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Unformatted text preview: Naming and Indexing of Chemical Substances for Chemical AbstractsTM 2007 Edition A publication of Chemical Abstracts Service Published by the American Chemical Society Naming and Indexing of Chemical Substances for Chemical AbstractsTM A publication of Chemical Abstracts Service Published by the American Chemical Society Copyright © 2008 American Chemical Society All Rights Reserved. Printed in the USA Inquiries concerning editorial content should be sent to: Editorial Office, Chemical Abstracts Service, 2540 Olentangy River Road, P.O. Box 3012, Columbus, Ohio 43210-0012 USA SUBSCRIPTION INFORMATION Questions about CAS products and services should be directed to: United States and Canada: CAS Customer Care 2540 Olentangy River Road P.O. Box 3012 Columbus, Ohio 43210-0012 USA Phone: Fax: E-mail: 800-753-4227 (North America) 614-447-3700 (worldwide) 614-447-3751 [email protected] Japan: JAICI (Japan Association for International Phone: Fax: Chemical Information) E-mail: 6-25-4 Honkomagome Bunkyo-ku, Tokyo Japan, 113-0021 81-3-5978-3621 81-3-5978-3600 [email protected] Countries not named above: Contact CAS Customer Care, 2540 Olentangy River Road, P.O. Box 3012, Columbus, Ohio 43210-0012 USA; Telephone 614-447-3700; Fax 614-447-3751; E-mail [email protected] For a list of toll-free numbers from outside North America, visit 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 102 NAMING AND INDEXING OF CHEMICAL SUBSTANCES 101. Foreword. Although the account which follows describes in considerable detail the selection of substance names for Chemical Abstracts (CA) indexes, it is not a nomenclature manual. It has the more restricted aim of enabling a user of CA indexes to proceed from the structure of an individual chemical compound to the place in the current Chemical Substance Index where the particular index name and any associated index entries will be found. This is the identical operation performed by a CA indexer when assigning an index name to a new or previously unnamed substance. What follows, in fact, is a comprehensive summary of CA substance indexing policies, which cover not only conventional organic and inorganic compounds but other completely defined substances entered in the Chemical Substance Index and given CAS Registry Number® identifiers. These substances include specific chemical elements, alloys, minerals, mixtures, polymers, enzymes, polysaccharides, and elementary particles. The chemical nomenclature used by Chemical Abstracts Service (CAS) has developed in parallel and generally in accordance with the rules published by the International Union of Pure and Applied Chemistry (IUPAC). Although these rules provide unambiguous text equivalents for the great majority of substances, equally acceptable alternative rules within the present IUPAC system often lead to two or more unambiguous names. This causes no difficulty in normal scientific communication, but is totally unacceptable in a formal, rigidly controlled, alphabetic listing such as the Chemical Substance Index. Here the names must be not only unambiguous, unique, and totally reproducible, but selected so as to bring the names of structurally related substances into juxtaposition in the alphabetical listing. They must be equally derivable by index users searching for information about individual substances and by those who prepare the index. It is also desirable that both should be able to use mechanical aids in name generation and retrieval. A major revision of CA index names was carried out in 1972 as the Ninth Collective Index period began. Most trivial names were dropped; exceptional treatment for various classes of substances was discontinued. Where, because of the stereochemical complexity of a natural product name, a trivial name was retained as a “stereoparent” (see ¶ 202), diagrams were furnished in the Chemical Substance Index to aid interpretation of index entries. The 1972 nomenclature revision and the reasons for its adoption are set forth in greater detail in the Ninth Collective Index Guide and in a journal article (J. Chem. Doc. 1974, 14(1), 3-15). The preferred CA index names for most chemical substances have been continued unchanged since that date. Changes in name-selection policies for the Twelfth (1987-1991) and Thirteenth (1992-1996) Collective Index periods affect alloys, carbohydrates (lactams), coordination compounds, formazans, index name selection (multiplicative names), inorganic compounds (line formulas of clusters, intermetallic compounds), molecular addition compounds (common components; hydrates), nitrilimines, onium compounds (free radicals), peptides, phosphonium ylides, phosphoryl halides and halogenoids, polymers (block, graft, and hydrolytic), ring systems (list of common systems), salts (lists of common anions), stereochemistry (sign of optical rotation), and zwitterions (inner salts, sydnones). The changes for the Fourteenth (19972001) Collective Index period affect coordination nomenclature, stereochemical practices, and stereoparents. The most recent changes (2007) involve locants, tautomers, and stereoparents. These changes, as well as the changes made in 1972, and in the Tenth (1977-1981) and Eleventh (1982-1986) Collective Index periods, are reviewed in Section G (¶¶ 225-293). The nomenclature of fullerenes is more fully documented in ¶ 163A of Section B. The arrangement of sections is as follows: A. B. C. D. E. F. G. H. J. K. L. M. Nomenclature Systems and General Principles (¶¶ 103-139) Molecular Skeletons (¶¶ 140-163A) Principal Chemical Groups (Suffixes) (¶¶ 164-177) Compound Classes (¶¶ 178-201) Stereochemistry and Stereoparents (¶¶ 202-212) Specialized Substances (¶¶ 213-224) Chemical Substance Names for Retrospective Searches (¶¶ 225293A) Illustrative List of Substituent Prefixes (¶ 294) Selective Bibliography of Nomenclature of Chemical Substances (¶¶ 295-308) Chemical Prefixes (¶¶ 309-311) Chemical Structural Diagrams from CA Index Names (¶¶ 312-318) Index The arrangement within each of these sections is indicated by a key at the beginning of the section. In the development of CAS policies for index names of chemical substances, no new nomenclature systems have been devised. Adaptation of current IUPAC rules to the specific needs of a highly ordered alphabetical index, not arbitrary coinage of new terms, has been the approach taken. It continues to be recognized by CAS that, while a unique name is needed for an index, and that this name, and the CAS Registry Number, are invaluable aids for substance identification, the use of this invariant index name for citation throughout every context in the scientific community is neither practicable nor desirable. But international agreement in chemical nomenclature, as embodied in the rules of IUPAC, IUB, and other organizations, continues to be of the greatest importance in restricting the arbitrary proliferation of substance names. References to individual rules which have formed the basis of CAS policies recorded in the sections that follow have not been cited, but the selective bibliography of the nomenclature of chemical substances which constitutes Section J contains a comprehensive list of current accepted rules. 102. Acknowledgement. CAS acknowledges the large contribution made by Cecil C. Langham in helping to develop and record CA name-selection policies for the Eighth Collective period (1967-1971) during the years immediately preceding his retirement in 1969. Dr. Langham’s work constituted an invaluable starting point for the revised name-selection policies introduced in 1972. A. NOMENCLATURE SYSTEMS AND GENERAL PRINCIPLES Introduction Inversion of names Name selection principles Order of precedence of compound classes Spelling Punctuation Enclosing marks Multiplicative prefixes “Mono” Functional derivatives ¶ 103 104 105 106 107 108 109 110 111 112 Order of citation of derivative terms Locants for substituent suffixes in substituent prefixes (radicals) for substituents on parents and parent radicals in multiplicative nomenclature for functional derivatives for indefinite compounds Alphabetization ¶ 113 114 115 116 117 118 119 120 121 ¶ 103 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 122 123 124 125 126 127 128 129 130 Substituent suffixes Substituent prefixes Compound radical names Carbonyl radicals Indicated hydrogen Added hydrogen Numbering of molecular skeletons Index name selection Subtractive nomenclature 2 ¶ 131 132 133 134 135 136 137 138 139 Tautomeric compounds Additive nomenclature Conjunctive nomenclature Multiplicative nomenclature Radiocofunctional nomenclature Replacement (“a”) nomenclature Replacement prefixes Replacement nomenclature for functions Substitutive nomenclature 103. Introduction. Many names may be employed in scientific publications for a single compound. Even so simple a compound as H2NCH2CH2OH can be named 2-Aminoethanol, 2-Aminoethyl alcohol, 2-Hydroxyethylamine, β-Hydroxyethylamine, 2-Hydroxyethanamine, 1-Amino-2-hydroxyethane etc., all of which describe it unambiguously; often, the less systematic (“trivial”) name Ethanolamine may be encountered. For more complex compounds, the number of possible names increases exponentially. In these circumstances, selection rules are essential if a single preferred name for citation in an index of chemical names is to be determined for each identifiable substance; lacking such a single name, information regarding the substance becomes scattered in the index. Beyond this, it is desirable that the selection rules bring chemically related substances close together in the index, and that they should be as consistent and as free from exceptions as possible. 104. Inversion of names. Ordering in the Chemical Substance Index is based on the index heading parent (1), which is often made up of a basic skeleton name, e.g., “Butane,” plus a suffix denoting the principal function, e.g., “-sulfonic acid.” A locant, e.g., “1-,” fixing its position is also often necessary. Following a comma (the comma of inversion) the substituents (2) are expressed in alphabetical order, e.g., “2,4-diamino-3- chloro-,” and the modification (3), now printed in boldface, completes the name by citing any derivatives of the principal function, e.g., “ethyl ester”, and stereochemical information (see ¶ 203) if appropriate. The uninverted name of the acid is 2,4diamino-3-chloro-1-butanesulfonic acid, and of the ester, ethyl 2,4-diamino-3chloro-1-butanesulfonate. The latter appears in the Chemical Substance Index as follows: 1 2 1-Butanesulfonic acid, 2,4-diamino-3-chloro1-ethyl ester 3 Also appearing in the boldface headings of certain very well-known substances are subdivision terms describing properties, etc., of the compound itself, or classifying certain derivatives of it, e.g., reactions, esters. 105. Name selection principles (see also ¶ 138). In choosing 1-Butanesulfonic acid as the heading parent in the example above, rather than, for example, 1,3-Butanediamine, an order of precedence of chemical functions and compound classes (¶ 106) was followed. In this hierarchy, sulfonic acids are ranked higher than amines. In the example cited, so-called substitutive nomenclature (¶ 130) was the type of nomenclature used. Generally, a preferred index name is determined by proceeding as follows until a decision is reached: (a) determine the most senior compound class; (b) determine the type of nomenclature that is appropriate; (c) determine the preferred index heading parent; (d) name the remainder of the structure as substituents, and/or as functional derivatives by modification phrases; (e) choose between alternatives where more than one unambiguous name is still possible. The remainder of Section IVA is devoted to detailing the application of these rules. 106. Order of precedence of compound classes, in descending order: (a) Free radicals and compounds for which substituent prefixes are unavailable, e.g., Sulfur diimide (¶ 200). (b) Cationic compounds: coordination cations, onium, aminium, ylium cations. (c) Neutral coordination compounds, including metallocenes. (d) Anionic compounds, e.g., Borate(1-). (e) Acids: peroxy acids, expressed as principal groups, in the order of the parent acids; acids, expressed as principal groups, in the order carbon,1 sulfur, selenium, tellurium; acids, expressed as functional parent compounds (¶ 130), in the order carbon (including Carbonic acid and Formic acid; see ¶ 183), chalcogen, nitrogen, phosphorus, arsenic, antimony, silicon, and boron. (f) Acid halides and related species, first in the order of the parent acid (see (e), above); then, for each acid, in the order fluoride, chloride, bromide, iodide, azide, isocyanate, isothiocyanate, isocyanide, cyanide (for non-carbon acid residues only). (g) Amides, in the same order as the parent acids (see (e), above). (h) Nitriles, in the same order as the parent acids (see (e), above). (i) Aldehydes, Thials, Selenals, Tellurals. (j) Ketones, Thiones, Selones, Tellones. (k) Alcohols and Phenols (of equal rank), Thiols, Selenols, Tellurols. (l) Hydroperoxides. (m) Amines. (n) Imines. (This is the lowest compound class expressed by a functional suffix; all the following classes are considered to be nonfunctional. For the ranking of nonfunctional cyclic and acyclic skeletons, see ¶ 138.) (o) Nitrogen compounds: heterocyclic; acyclic (other than “a”-named chains; see ¶ 127), e.g., Triazane, Diazene, Hydrazine, Hydroxylamine, Thiohydroxylamine. (p) Phosphorus compounds: heterocyclic, acyclic (other than “a”-named chains; see ¶ 127), e.g., Diphosphine, Phosphine oxide, Phosphine sulfide, Phosphine imide, Phosphorane, Phosphine. (q) Arsenic compounds (in similar order). (r) Antimony compounds (in similar order). (s) Bismuth compounds (in similar order). (t) Boron compounds: carbapolyboranes, hetero polyboranes, polyboranes, heterocyclic, Borane. (u) Silicon compounds: heterocyclic, acyclic (other than “a”-named chains; see ¶ 127), e.g., Disiloxane, Disilathiane, Trisilane, Disilane. Note that the order is determined first by the total number of skeletal atoms, then by the presence of oxygen, sulfur, etc; see ¶ 128. (v) Germanium compounds (in similar order). (w) Tin compounds (in similar order). (x) Lead compounds (in similar order). (y) Oxygen compounds other than “a”-named chains (see ¶ 127): heterocyclic; acyclic polyoxides, e.g., Trioxide, Peroxide. (z) Sulfur compounds: heterocyclic; acyclic polysulfides and their oxides, e.g., Trisulfone, Trisulfide, Disulfone, Disulfoxide, Disulfide. (aa) Selenium and tellurium compounds (in similar order). (bb) Carbon compounds: carbocyclic (cc) Silane (dd) Carbon compounds: acyclic 107. Spelling. CAS accepts Merriam-Webster’s Collegiate® Dictionary2 as the primary authority for spelling; e.g. sulfur (not sulphur); aluminum (not aluminium). Random House Webster’s Unabridged Dictionary3 is used for words not found in the Collegiate Dictionary. Elision of vowels is often practiced in combining the segments of names: e.g., in Butanone and disiloxanyl the final “e” of the basic skeleton name has been dropped; in Oxazepine an “a” has been omitted twice, after “oxa” and before “ep”; and “a” is often omitted before a multiplied “amine” or “one” suffix, as in Benzenetetramine and Cyclohexanehexone; the terminal “o” of acenaphtho, benzo, naphtho, and perylo, and the terminal “a” of cyclobuta, etc., are elided before vowels, e.g., Benz[cd]indole, 5H-Cyclobut[f]indene. Other examples of elision are -imidic (not -imidoic) acids; -imidamides (not imidoamides); -thiones (not thioones); and -hydrazonamides (not -hydrazonoamides). Examples will be found in later paragraphs. In a few cases, the vowel “o” is added for euphony, e.g., Carbonothioic acid (not Carbonthioic acid). Elision of entire syllables is now uncommon. Remaining examples include methoxy, ethoxy, propoxy, butoxy, phenoxy (not (methyloxy), etc.) radicals, and the thienyl (not thiophene-yl) radical. Carbamic acid is an elided form of Carbonamidic acid (¶ 183); Sulfamic acid is used in place of Sulfuramidic acid, and Sulfamide instead of Sulfuramide or Sulfuric diamide. The suffix “-carboxylic acid” undergoes various forms of elision in formation of replacement names, e.g., “-carbothioamide.” 108. Punctuation in chemical names is frequently of great importance in removing ambiguities and in differentiating one substance from another. Lower case italic Roman letters are used in fusion prefixes (¶ 151) in ring system names, and in as- and s-Indacene; capital italics such as N-, O-, P-, S-, are locants indicating substitution on these hetero atoms; H- denotes indicated or added hydrogen (¶¶ 135, 136); italic Arabic numerals are locants for atoms in abnormal valency states (¶ 158) and for “labeled” atoms (¶ 220); italic words and syllables are used in modifications to express isomeric oxides, e.g., thionooxide at a thio acid heading parent, and in stereochemical descriptors (¶ 203), e.g., erythro-, tetrahedro-. The small capitals D-, L-, and DL-, are configurational descriptors (¶ 203); like italic letters, they are disregarded in placing chemical names in order until Roman letters have been alphabetized. The “comma of inversion” has been mentioned above (¶ 104). Other commas are used between individual locants in index heading parents, substituents, 1 Acetic acid and Benzoic acid are ranked here as though they were named Ethanoic acid and Benzenecarboxylic acid, respectively. 2 Merriam-Webster’s Collegiate® Dictionary, 11th ed., Merriam-Webster, Springfield, MA, 2003. 3Random House Webster’s Unabridged Dictionary, 2nd ed., Random House, N.Y., 2001. 3 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 111 and modifications. Different types of functional derivatives are separated by commas in the text of the modification. Examples: (a) (b) (c) hydrazone phenylhydrazone diethyl ester, sodium salt ethyl methyl ester, hydrochloride are also employed around a ring-assembly name when it is followed by a principal-group suffix or forms part of a radical name. Examples: [1,2′-Binaphthalene]-2-carboxylic acid [1,1′-biphenyl]-4-yl Brackets enclose structural features of bridges or component rings when the enclosed locants are not applicable to the total system. Examples: 4a,9a-[2]Butenoanthracene 4H-[1,3]Oxathiolo[5,4-g]benzoxazole (the “2” locates the double bond in the buteno bridge) (formed by fusion of 1,3-oxathio with benzoxazole; in the total ring system, the oxygen and sulfur atoms of the oxathiole ring are in the 6- and 8-positions respectively) Hyphens at the end of the set of substituents in the inverted part of a boldface heading signify that no space is intended when the name is uninverted for use in textual matter. Conversely, absence of a hyphen after substituents at headings such as Disulfide, Hydroperoxide, Peroxide, indicates that a space appears at that point in the uninverted name. Examples: Acetic acid, 2-chloro2-Chloroacetic acid Disulfide, bis(2-chloroethyl) Bis(2-chloroethyl) disulfide (index name) (uninverted name) (index name) (uninverted name) Hyphens separate locants from the words and syllables of a name; when used between locants, the intention is to indicate that such locants refer to different parts of the name; e.g., in Acetamide, N-2-naphthalenyl-, the “N-” places the 2-naphthalenyl substituent on the nitrogen of the heading parent, Acetamide. Periods separate ring size descriptors in Von Baeyer and spiro names, e.g., Bicyclo[3.2.0]heptane. Colons separate sets of locants already related to one another; if a further step is called for, semicolons are employed. Examples: 1,4:5,6-Dimethanonaphthalene Benzo[1′′,2′′:3,4;5′′,4′′:3′,4′]dicyclobuta[1,2-a:1′,2′-a′]diindene 109. Enclosing marks are placed around compound substituent radicals and around and within complex radicals (¶ 162). Their presence or absence frequently removes ambiguity, especially when locants are omitted through lack of precise structural information. Examples: MeSiH 2 C l C lC H 2 S iH 3 CO 2H CO Cl CO 2H CO Cl CO 2H CO Cl When a multiplicative index name is uninverted, brackets are placed around the heading parent. Examples: Acetic acid, 2,2′-oxybis2,2′-Oxybis[acetic acid] Benzoic acid, 4,4′-methylenebis[2-chloro4,4′-Methylenebis[2-chlorobenzoic acid] (index name) (uninverted name) (index name) (uninverted name) Brackets are sometimes needed for functional terms in modifications, especially following locants or multiplicative prefixes. Examples: S-[(dodecylthio)methyl] ester bis[(2,4-dinitrophenyl)hydrazone] 110. Multiplicative prefixes. Generally, prefixes derived from the Greek (di, tri-, etc.) are used, rather than the Latin (bi-, ter-, etc.); exceptions are nona(not ennea-) for nine, and undeca- (not hendeca-) for eleven. (For lists of Latin and Greek prefixes, see ¶ 309.) The Latin prefixes bi-, ter-, etc., are used for ring assemblies. The prefixes bis-, tris-, tetrakis-, etc., are used for compound and complex radicals and functional derivatives, and to avoid misunderstanding in other cases, especially with names beginning with replacement terms like “aza” or “oxa”, fusion prefixes like “benzo” or “naphtho,” or compound fusion prefixes like “cyclopentapyrido.” They are used always in multiplying a heading parent. Examples: bis(methylene) bis(2-aminoethyl) [1,2-ethanediylbis(oxymethylene)] bis(O-methyloxime) bis(cyclohexaneacetate) tris(dihydrogen phosphate) bis(aziridinyl) bis(2,1-diazenediyl) bis([1,1′-biphenyl]-4-yl) bis(bicyclo[2.2.1]hept-2-yl) tris(decyl) tetrakis(1-aziridinyl) bis(benz[a]anthracen-1-yl) Benzo[1,2-c:3,4-c′]bis[1,2,5] oxadiazole Biscyclopenta[5,6]pyrido[4,3b:3′,4′-c]pyridine Benzoic acid, 2,2′-silylenebisPhosphonic acid, P,P ′-1,4phenylenebis- Silane, chloromethylSilane, (chloromethyl)Benzoic acid, 3-(chlorobenzoyl)- Benzoic acid, (3-chlorobenzoyl)- Benzoic acid, 3-(3-chlorobenzoyl)- Parentheses are placed around compound substituents like “(chloromethyl)”, above; in a case like (chloromethylamino), it is to be understood that both the chlorine atom and the unsubstituted methyl group are substituents of the amino group, i.e., Cl(CH3)N-. The alternative structure, ClCH2NH- is named [(chloromethyl)amino], which is a complex substituent prefix. Parentheses are used around simple radicals when they are preceded by “bis,” “tris,” etc. (¶ 110), e.g., bis(methylene), tris(decyl). They are used also to separate locants of the same kind which would otherwise be separated only by hyphens, to indicate the second atom involved in double-bond formation when it is not the next in the numbered pathway, to enclose parts of a heading parent, to set off added hydrogen, and to enclose multiplied terms in modifications, ion terms that would otherwise be ambiguous, Ewens-Bassett numbers (¶ 215), descriptive terms and ratios, and parts of synonym line formulas. Examples: Benzoic acid, 4-(2-naphthalenyl)Bicyclo[4.2.0]oct-1(6)-ene Butane(dithioic) acid (see ¶ 165) 1(2H)-Naphthalenone bis(inner salt) (disulfate) (from Disulfuric acid) iron(3+) salt compd. with benzenamine (1:1) acetate (salt) Thioperoxydiphosphoric acid ([(HO)2P(O)]2S2) Brackets enclose complex substituent prefixes and derivative terms, as well as Von Baeyer and spiro ring size designations (already described above). They 111. “Mono” is only rarely employed in index heading parents (an example is Peroxymonosulfuric acid) but is needed to express functional derivatives of polyfunctional heading parents and inner salts when needed. It is not used if a locant is necessary, or when only one functional group is present. Mono is used for esters of polybasic mononuclear acids having only one type of chalcogen atom, e.g. monoesters of carbonic acid, phosphonic acid, etc. The term “hydrogen” in an uninverted ester name precludes the use of “mono.” Examples: M e C( =N O H ) M e 2−Propanone, oxime Carbonic acid, monomethyl ester M e O CO 2 H OH OAc 1,2−Naphthalenediol, 2−acetate Phosphoric acid, ethyl dimethyl ester 1,2,3-Oxadiazolium, 2-(dimethylamino)-4(dimethylsulfonio)-5hydroxy-, mono(inner salt) E tO P( O ) ( O M e ) 2 + S−Me Μe 2Ν−Ν N O Me O- ¶ 111 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 2,5-Cyclohexadiene-1,4-dione 1-(phenylhydrazone), 4-oxime (previously mono(phenylhydrazone), oxime, but now locants are used.) Phosphoric acid monoethyl ester (index name) Ethyl dihydrogen phosphate (uninverted name) 4 P hN H N NOH E tO P (O )(O H ) 2 (f) other additive terms describing portions of the molecular structure not covalently attached, e.g., compd. with..., hydrate, mixt. with..., polymer with.... 114. Locants. When a choice is necessary, italic Roman letters are placed before Greek letters, and Arabic numerals are placed last, e.g., As, N, P, S, α, β, γ, 1, 2, 3. (For the Greek alphabet see ¶ 310.) Unprimed locants are followed by primed locants, then by doubly primed locants, etc., e.g., N , N ′ , S, α, 1′, 2, 2′, 2′′, 3. Low numbering of indices (superscript Arabic numbers) and application of primes are not considered until regular numerical locants have been chosen. Examples: M e P( =N M e ) ( N H M e ) 2 112. Functional derivatives of the principal reactive chemical groups of systematically-named index heading parents are cited in the modification; these derivatives, as defined for indexing purposes, are restricted to acyclic anhydrides, esters, hydrazides, hydrazones, and oximes. Other derivatives, such as semicarbazones, azines, acetals, and cyclic esters, are named in other ways, e.g., substitutively at the highest functional heading parent, as substituted hydrazones, etc., or as heterocycles, as detailed in Section D, below. Functional derivatives of subsidiary functions (those not expressed by the suffix of the heading parent) are cited in the main boldface heading as compound or complex substituents. Examples: E tC O 2 4 1 Phosphonimidic diamide, N,N ′ ,N ′′ ,PtetramethylBenzenemethanamine, N , α ,4-trimethyl1,3-Benzenediamine, 4-chloro-N3methyl- (not 1,3- Benzenediamine, 6-chloro-N1-methyl-) Me CH M e N H M e Cl MeNH NH2 CO 2 Me Benzoic acid, 4-(1-oxopropoxy)methyl ester (not Benzoic acid, 4-hydroxy-, methyl ester, propanoate) Butanal, 3-hydrazono- (not Butanal, 3-oxo-, 3-hydrazone) O O 1,1′:4′,1′′-Terphenyl, 2 ′ ,2 ′′-dichloro(not 1,1′:4′,1′′-Terphenyl, 2,3′-dichloro-) Cl Cl NNH2 C H 3 — C — C H 2 — CHO 4 3 2 1 Locants for unsaturation in compounds named as index heading parents are always cited when the compound contains three or more skeletal atoms, except for monocyclic hydrocarbons with one multiple bond and no suffix. Examples: H N =N N H 2 1 3 1-Triazene 1,2-Propadiene 1-Buten-3-yne Ethene CH 2 — C — O — C — CH 3 C H 3O O C —C H 2 — C H 2 — C H — CH 2 — C H 2 — COOCH 3 7 6 5 4 3 2 1 H 2 C=C=CH 2 H 2 C=CH C ≡ CH 1 4 Heptanedioic acid, 4-[2-(acetyloxy)2-oxoethyl]1,7-dimethyl ester (not Heptanedioic acid, 4-(carboxymethyl)-, 4-anhydride with acetic acid, dimethyl ester) O 2 1 H 2 C = CH 2 Cyclohexene CH3 1 5 H O — P — O — CH 2 — C H 2 — N + — CH 3 −O CH 3 1,3-Cyclopentadiene Ethanaminium, N,N,N-trimethyl-2(phosphonooxy)inner salt (not Ethanaminium, 2-hydroxy-N,N,N-trimethyl-, dihydrogen phosphate (ester), inner salt) NOH F 4 1 Locants denoting ring junctions of ring assemblies are always cited except for two-component assemblies of cycloalkenes, cycloalkadienes, etc. Examples: 1 1′ 1,1′-Biphenyl N 6′ C O 2 CH 2 CMe Benzoic acid, 4-fluoro2-(hydroxyimino)propyl ester (not Benzoic acid, 4-fluoro-, 2-oxopropyl ester, oxime) Benzoic acid, 4-[(acetyloxy)sulfonyl]methyl ester (not Benzoic acid, 4-sulfo-, S-anhydride with acetic acid, methyl ester) 6 N 1 1′ 2,2′-Bipyrazine N 4′ 4 N 6 1 1′ Bi-2-cyclohexen-1-yl 6′ A cO SO 2 4 1 CO 2 Me 113. Order of citation of derivative terms in modifications. The normal order is: (a) the term “inner salt”; (b) functional derivatives in the order: anhydrides, esters, hydrazides, hydrazones, oximes; multiplicative terms are cited before simple terms, e.g., 1,3-propanediyl dimethyl ester (with the appropriate locants), otherwise alphabetic order is followed; (c) additive terms describing fragments covalently attached to the index heading compound, e.g., N-oxide; (d) ionic terms, e.g., ion(1-), radical ion(1-), then ionic terms derived from separate structural fragments, e.g., chloride, acetate, or an “amminium” heading; (e) metal salts, followed by other salts alphabetically, e.g., acetate, hydrochloride; 115. Locants for substituent suffixes of index heading parents are cited except for the following cases: mononuclear skeleton parents, a single substituent suffix on a homogeneous molecular skeleton with two skeletal atoms, or a single substituent suffix on benzene or a saturated homogeneous monocyclic ring. Locants are not cited for Geneva suffixes which terminate a chain, e.g., “-oic acid’, “-dial”. Examples: CN CN CN CN | | | | N C — C = C — C = C — CN 1 2 3 4 1,3-Butadiene-1,1,2,3,4,4-hexacarbonitrile O 6 5 H N 1 3 O NH HN 1,3,5-Triazine-2,4,6(1H,3H,5H)trione O 5 N CO2 H Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 O H2 Si O N Si H2 Si O ¶ 118 2-Pyrazinecarboxylic acid cyclotrisiloxan-2-ylidene HO2CN=NCO2H H 2 C= C H C O 2 H 1,2-Diazenedicarboxylic acid O 2-Propenoic acid 1,4-dioxan-2-yl O N C H 3 C H 2 O C H 2 C H 2 OCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 COOH 15 14 13 12 11 10 9 8 76 5 43 2 1 2-pyrazinyl 4,7,10,13-Tetraoxapentadecanoic acid O O N 2-oxiranyl 2-Cyclopropen-1-one 116. Locants in substituent prefixes (radicals). Locants are assigned for multiple bonds and for free valencies in all unsaturated radicals containing three or more skeletal atoms. Locants are always cited for free valencies involving more than one position of a skeleton. Examples: H 3 C− C H = C H − C Η 2 − 2-buten-1-yl HC≡CCH= 3 1 2-propyn-1-ylidene Locants are not cited for free valencies on charged heteroatoms in cationic heterocyclic rings containing only one heteroatom, e.g. oxiranio-. 117. Locants for substituents on index heading parents and parent radicals are cited when the parent names possess locants for substituent suffixes, unsaturation, hetero atoms, indicated hydrogen, spiro or ring assembly junctions, or bridges (in fused systems). Locants are dispensed with for “hydro” prefixes in fully saturated ring systems unless ambiguity could result, e.g., because of a remaining etheno or other unsaturated bridge. Locants are not cited for a single substituent on a homogeneous monocyclic ring, e.g., benzene, methyl-. Similarly, locants are not cited for single substituents on homogeneous parents, or parent radicals containing only two skeletal atoms, or for one or more substituents on mononuclear radicals. Examples: O HO Cl O Cl OH HN=NNH— 3 1 2-triazen-1-yl 2,3-Oxiranediol, 2,3-dichloro- 2,4-cyclopentadien-1-ylidene Cl OH 2-Oxirenol, 3-chloro- —N = N N H — 1 3 1-triazene-1,3-diyl M e CO CO CH 2Cl 2,3-Butanedione, 1-chloro- —C ≡ C C ≡ C — 1,3-butadiyne-1,4-diyl H 2 N CO N H M e Me O Me Urea, N-methyl- —C H 2 C H 2 — 1,2-ethanediyl Me O Me 1,4-Dioxin, 2,3,5,6-tetramethyl- C=C 1,2-ethenediylidene Ph C ≡ CC ≡ C— 4 1 (4-phenyl-1,3-butadiyn-1-yl)- O 1,2-cyclopropanediyl O 1,4-Naphthalenedione, octahydro- 1,4-phenylene Locants are not cited for free valencies of radicals that have lost hydrogen from one skeletal atom of a saturated homogeneous cyclic or acyclic molecular skeleton or an unsaturated molecular skeleton of two atoms. Locants are not cited for a phenyl radical. Locants are cited for free valencies of all other radicals derived from cyclic parents. Locants are not cited for free valencies on acyclic radicals with only one possible site of attachment, e.g., acetyl, ethoxy, sulfonimidoyl, etc. Examples: MeC H 2 — HN=N— HP − P — || HP − PH P hC O − When one or more locants are needed for substituents on a heading parent or parent radical, all are cited. Examples: Ph CO CO− Ph Methanone, 1,1′-(1,4-phenylene)bis[1phenyl- ethyl diazenyl 118. Locants in multiplicative nomenclature are always cited for the positions of attachment on the heading parent, even for single atom parents. Skeletal locants are also cited for parents that are multiplied by esterification, hydrazides, hydrazones or oximes. When a multiplied acid has more than one kind of chalcogen atom or has both carboxylic and carboperoxoic groups (or their chalcogen analogues), superscript skeletal locants are used in combination with the heteroatom locants. Examples: Ph O Ph tetraphosphetanyl Benzene, 1,1′-oxybisBenzene, 1,1′-oxybis[4-fluoro- benzoyl F O F 5 1 2-cyclopenten-1-yl H O2 CCH 2 N H N H CH 2 CO 2 H Acetic acid, 2,2′-(1,2-hydrazinediyl)bis- ¶ 118 H O 2 C N H S iH 2 N H CO 2 H MeSMe Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Carbamic acid, N,N ′-silylenebisMethane, 1,1′-thiobisSilanol, 1,1′-methylenebisSilanamine, 1,1′-methylenebisAcetic acid, 2-chloro-, 1,1′-(1,2-ethanediyl) ester Phosphonothioic acid, P,P ′-methylenebis-, OP,OP,OP′,OP′-tetramethyl ester 6 H O S iH 2 C H 2 SiH 2 OH H 2 N SiH 2 C H 2 S iH 2 NH 2 C lC H 2 C O O (C H 2 ) 2 OCOCH 2 Cl 120. Locants for indefinite compounds must often be omitted. In addition, such compounds can sometimes be named only by departing from the regular name selection policies, e.g., by citation of the principal group in the modification instead of as a suffix of the heading parent, citation of a functional derivative in the modification rather than as a substituent, use of “mono” instead of the (unknown) locant, replacement of a numerical locant by the indefinite aromatic locant “ar-,” or inclusion of question marks in a set of otherwise known locants. Examples: S = − O Me S − = O Me MeO − P − C H 2 − P − OMe 119. Locants for functional derivatives are always cited when there is more than one occurrence of the principal functional group. Examples: 1 Benzenediamine Benzoic acid, dichloroNaphthalene, 2,2′-(1,4-phenylene)bis-, disulfo deriv. Benzeneacetic acid, 2-carboxy-, monomethyl ester 1,2-Ethanediol, 1-phenyl-, monocarbamate Naphthalene, ar-chloro-1,2,3,4-tetrahydroBenzenemethanol, ar-amino[1,1′-Biphenyl]-ar,ar′-dicarboxylic acid Benzene, 1,2,?-trimethylThe italic word “or” is used with substituent prefixes (but never with index heading parents) when the number of alternative structures cannot be misinterpreted. Examples: Quinoline, 2-chloro-3(or 4)-methylNaphthalene, 1(or 2)-ethyl-2(or 1)-methyl- CO2 Me 1,2-Benzenedicarboxylic acid, 3-methyl-, 1-methyl ester Me CO2 H 1 O a2 O || C H2 —O —C—CH 3 a3 2,3-Furandimethanol, α 3-chloro-, α 2-acetate C H —O H | Cl MeOP(O) (OH)OP(O) (OH) OMe p′ P When one or more substituent prefixes are in known positions and the remainder in unknown positions, lowest locants are used for the former. Example: Naphthalene, chloro-2-methyl- Diphosphoric acid, P,P ′-dimethyl ester Butanedioic acid, 1-hydrazide 2,3-Butanedione, 2-(phenylhydrazone), 3-oxime 1,4-Benzenedicarboxylic acid, 1,4-dimethyl ester H O 2 C (C H 2 ) 2 C O NHNH 2 MeC ( =N O H )C Me = NNHPh MeO − C O CO− OMe Locants are cited for esters of compounds named at an alcohol parent. Examples: H 2 N− (C H 2 ) 2 O C O CH 3 Ethanol, 2-amino-, 1-acetate (the term ester is not cited because a locant is present.) Benzeneethanol, 1-acetate (for a conjunctive name, the ring locant is used.) An indefinite name like Piperidine, 2(or 4)-bromo-4(or 2)-chloro- cannot be used because this name could be held to include the 2-bromo-2-chloro- and 4-bromo-4-chloro-isomers; in such cases locants are usually omitted. 121. Alphabetization of substituent prefixes affects the position in the index where an inverted chemical substance name will be found. Simple prefixes are placed in alphabetic order according to their names; only then are multiplicative prefixes (di-, tri-, etc.) placed in front of each as required, and locants inserted; e.g., an index compound in which two nitro groups, three bromine atoms, and a chlorine atom are present receives the substituent name “tribromochlorodinitro,” and the substituents so arranged will be found together with an appropriate index parent, such as Naphthalene, alphabetized in accordance with all the Roman letters in the complete name. The total name with locants, e.g., Naphthalene, 2,5,8-tribromo-3-chloro-1,6- dinitro-, will be preceded in the list of index entries by both Naphthalene, nitro- and Naphthalene, tetrachloro-. Compound and complex substituent prefixes (radicals) are constructed on similar alphabetic principles and then arranged by their first letters (which may have been derived from multiplicative prefixes within the radicals) in the total name. This name is then placed in the index as described above, all letters being alphabetized. When the letters are all identical, arrangement depends on locants. Examples: CO 2 H E t 2N ( CH 2) 2 6 1 PhC H 2 C H 2 O C O C H 3 (CH2) 2 NEt Cl 2 Locants are used in modifications for index headings that express the same (or similar) functions in both the index parent and the substituents when the latter are not derivatized. This avoids confusion with former CA index names. Examples: C O 2 Et HO3 S Cl Cl Benzoic acid, 3,4,5-trichloro-2,6bis[2-(diethylamino)ethyl]- (letter "c" is placed before "d", the initial letter of the complex radical) CO2H Benzoic acid, 3-sulfo-, 1-ethyl ester Br 8a 1 Br 5 4 CO 2 H E tO 3 S Benzoic acid, 3-(ethoxysulfonyl)(formerly Benzoic acid, 3-sulfo-, 3-ethyl ester) O2 N N [ ( CH 2 ) 2 Cl] 2 1-Naphthalenecarboxylic acid, 4[bis(2-chloroethyl)amino]-6,7-dibromo- (the multiplicative prefix "bis-" is part of the name of the complex substituent prefix and this is therefore placed before "bromo") NO2 8a 1 The locant for an additive term such as “oxide” is an Arabic number when a nitrogen, phosphorus, sulfur, etc., atom of a ring in the index heading parent is involved; otherwise a letter locant (N-, S-, etc.) is employed. Locants are not employed for ionic modification terms, e.g., salts such as “sodium salt,” “hydrochloride.” 5 4 Naphthalene, 2-(2-nitrophenyl)-7(3-nitrophenyl)- (the radicals are placed in order, according to the locants they contain, before locants relating to the heading parent are inserted) 7 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 122 122. Tautomeric compounds. Index names are normally based on the precise structures shown or described in the author’s original document. Tautomerism (ready interconvertibility of isomers) in certain types of compounds causes a serious problem in index-name selection, the issue here being not which name to select for a given molecular structure but which diagram to name for a given tautomeric system if scattering at different names of information about what is essentially a single substance is to be avoided. Common (trivial) names for most nitrogenous tautomeric systems are cross-referred to preferred systematic names. Examples: Adenine. Barbituric acid. Caffeine. Carbostyril. Cytosine. Guanine. Hydantoin. Melamine. Theophylline. Uracil. Uric acid. Xanthine. See 9H-Purin-6-amine See 2,4,6(1H,3H,5H)-Pyrimidinetrione See 1H-Purine-2,6-dione, 3,7-dihydro-1,3,7-trimethylSee 2(1H)-Quinolinone See 2(1H)-Pyrimidinone, 4-aminoSee 6H-Purin-6-one, 2-amino-1,9-dihydroSee 2,4-Imidazolidinedione See 1,3,5-Triazine-2,4,6-triamine See 1H-Purine-2,6-dione, 3,9-dihydro-1,3-dimethylSee 2,4(1H,3H)-Pyrimidinedione See 1H-Purine-2,6,8(3H)-trione, 7,9-dihydroSee 1H-Purine-2,6-dione, 3,9-dihydro- A unique CA Chemical Substance Index name is selected for each compound containing a normalized tautomeric structure by application of the rules that follow (see II, below). For tautomeric pyrazole derivatives and for tropolones, CA selects a single preferred structure and index name, and assigns a single CAS Registry Number, even though these systems do not conform to the general equilibrium illustrated above and are not currently normalized by the CAS Registry System. Lowest locants are employed successively in index parents and substituents in these cases. Examples: Me 5 H N 1 2 N2 CH 2 O H Me N 5 1 NH CH2 O H 1H-Pyrazole-3-methanol, 5-methyl(principle: lowest locant for principal group) NOT 1H-Pyrazole-5-methanol, 3-methyl- O 1 7 OH Br OH 7 1 O Br The necessity for many tautomeric structures to be redrawn to agree with selected CA index names is obviated by computer “normalization” algorithms in the CAS Registry System. In the normalization process, the different structural diagrams for a single tautomeric system (of one of the types expressed in the cross-references above) are recognized as equivalent and stored in identical machine-language representations. They share a single unique CAS Registry Number and CA Chemical Substance Index name. The structural requirements for the normalization process and the rules for selecting unique CA Chemical Substance Index names are as follows: I. Requirements for normalization of structures. Tautomeric structures represented by the following equilibrium: M= Q − ZH HM − Q= Z 2,4,6-Cycloheptatrien1-one, 3-bromo-2hydroxy(principle: lowest locants for substituents) NOT 2,4,6-Cycloheptatrien1-one, 2-bromo-7-hydroxy- For phosphonic-phosphorous and phosphinic-phosphonous acid tautomers, see ¶ 197. II. Rules for Choosing the Preferred Normalized Tautomer. These rules are used to select the particular structure of a tautomer from which the unique CA Chemical Substance Index name is then derived. They are applied in the order shown until a decision has been made. Rule 1: The Stereo Retention Rule are normalized, i.e., recognized as equivalent in the CAS Registry System, when the following requirements are met: (a) Q = C, N, S, P, Sb, As, Se, Te, Br, Cl or I with any acceptable valency for the individual elements. (b) M and Z = any combination of trivalent N and/or bivalent O, S, Se or Te atoms. (c) The bonds involved in tautomerization may be in an acyclic chain or in a ring system or partly in both. (d) The end-points, M and Z, may be in adjacent rings of a fused ring system, but a nitrogen atom which occupies a fusion point in such a system cannot take part in tautomerization. (e) The hydrogen atom of the tautomeric system may be replaced by deuterium or tritium. (f) Two or more systems of the form shown above may be linked through a common atom, whereby a proton can be considered to migrate along the chain. Example: —N H − C =N − C =N − C= N— —N =C − N =C − N H − C= N— When the original document reports the isolation of a normalized tautomer with an E or Z double bond connecting the central atom Q to a terminal N, the preferred tautomer retains the E or Z configuration. Z C N OH NO2 H N N E CH3 NH2 Ethanimidic acid, N-nitro-, (1Z)- 2(1H)-Pyridinone, hydrazone, (2E)- Ph N H N Z Me N | | | 1-Triazene, 1-methyl-3phenyl-, (1Z)- —N= C − NH − C= N − C =N — —N= C − N= C − N= C − N H — | | | | | | | | | Rule 2: The Oxo Rule For any tautomer mobile group, if M is a chalcogen and Z is N, the preferred tautomer has the mobile H on N; and if M and Z are both chalcogens, the preferred tautomer has the mobile H on the chalcogen of higher atomic number. The overall order of priority for attachment of the mobile H is then N > Te > Se > S > O In other words, a double bond to oxygen is preferred above all others. H N O N OH Replacement in the generalized formula above by specific elements affords normalized tautomeric systems such as the following: | | —NH − C = N— —N = C −ΝΗ — (amidine tautomerism) —NH − N = N— — N = N − NH— | NOT (diazoamino tautomerism) —N H − C = O (S, Se , Te ) | —N = C − O( S, Se , T e ) H 2(1H)-Pyridinone 2-Pyridinol (lactam-lactim tautomerism) —NH − P = N— O || —S − NH 2 || O —N = P − NH— S OH | —S = NH || O Ph C NH2 NOT Ph SH C NH Benzenecarbothioamide Benzenecarboximidothioic acid ¶ 122 O HO P OH NH O P OH OH Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 O NOT HO P OH N OH P OH OH O N NH N O O H N N N O 8 NOT 2H-Pyrrol-2-one, 5,5′iminobis- Imidodiphosphoric acid Phosphorimidic acid, N-phosphonoRule 5: The Alternating-Bond Rule 2H-Pyrrol-2-one, 1,5-dihydro5-[(2-oxo-2H-pyrrol-5yl)imino]- O P SeH NOT HO P Se For a cyclic tautomer mobile group in which M and Z are both N and Q lies at the junction of two rings, the preferred tautomer has one N in a ring with alternating single and double bonds and the mobile H on the other N. H N N N N H O H N O 1H-Phosphole, 1-selenyl-, 1-oxide 1H-Phosphole, 1-hydroxy-, 1-selenide NOT N N H N Rule 3: The Unsubstituted Imino Rule For an acyclic tautomer mobile group, if M and Z are both N, the order of priority for attachment of the mobile H is R−N > T−N > D−N > H−N 6(5H)-Pteridinone, 7,8-dihydroNH2 N 6(5H)-Pteridinone, 1,7-dihydroNH2 H N O N N H N O NOT HN where R is any covalently attached atom or group other than H, D, or T. In other words, an unsubstituted imino group is preferred to a substituted one, and an unlabeled imino group is preferred to a labeled one. N N H 8H-Purin-8-one, 6-amino7,9-dihydroH N 8H-Purin-8-one, 6-amino1,7-dihydroH N N Et NH C NH NOT Et N N C NH2 N O N O NOT 1-Piperidinecarboximidamide, N-ethylO Ph S NH NH Ph NOT 1-Piperidinecarboximidamide, N ′-ethylO Ph S NH2 N Ph N N H O N H N O Pyrazino[2,3-b]pyrazine-2,3dione, 1,4-dihydro- Pyrazino[2,3-b]pyrazine-2,3dione, 5,8-dihydro- Rule 6: The Tautomer CIP Rule For the isolated (n = 1) or extended (n > 1) tautomer R NH Q N n R′ Benzenesulfonimidamide, N-phenylNH NOT Et C NHNH2 Benzenesulfonimidamide, N ′-phenylNH 2 Et C NNH2 in which a) R and R′ are any covalently attached atoms or groups, and b) both terminal N’s (those attached to R and R′) are acyclic or both are in a ring, the preferred tautomer has the mobile H on the terminal N of higher priority based on the Cahn-Ingold-Prelog (CIP) sequence rule, the one used to assign absolute configuration [R. S. Cahn, C. K. Ingold, and V. Prelog, Angew. Chem. Int. Ed. Engl., 1966, 5, 385-415 (errata: 1966, 5, 511); V. Prelog and G. Helmchen, ibid., 1982, 21, 567-583. N D Propanimidic acid, hydrazide Propanehydrazonamide NH NOT Et C NH D Et NH 2 C Propanimidamide-N-d Propanimidamide-N ′-d For each tautomer, a tree diagram is constructed for the terminal N bearing the mobile H. Then the following CIP-based rules are used: Subrule 6.1: The Element Subrule Rule 4: The Amino/Hydrazinyl Rule For a tautomer mobile group in which M and Z are both N, but one N is in a ring and the other is attached to the ring, the preferred tautomer has the mobile H on the acyclic N. N NHNH 2 NOT H N NNH 2 Under subrule 6.1, at the first point of difference, the element with the higher atomic number has priority. The terminal N for that branch is then assigned the mobile H in the preferred tautomer. N HN O2N N NH 2 N NOT O2N N NH NH 2 Pyridine, 2-hydrazinyl- 2(1H)-Pyridinone, hydrazone H N NH 1H-1,2,3-Triazol-4-amine, 5-nitro- 1H-1,2,3-Triazol-5-amine, 4-nitro- H N N Br NH H N P N Br N P N H NH 2 NOT NOT 1H-Imidazol-2-amine 2H-Imidazol-2-imine, 1,3-dihydro- 1H-1,3,2-Benzodiazaphosphole, 6-bromo- 1H-1,3,2-Benzodiazaphosphole, 5-bromo- 9 NH2 N N N N H Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 NH2 ¶ 124 unlike pair (R,S or S,R): H N NOT N N N CO2H Me NH H C N R CH S CH Et CH S CH S Et NOT H C NH N CO2H Me CH S R CH CH S S CH Et 9H-Purin-6-amine 7H-Purin-6-amine Et CO2H Me HN O N Me Me N NH Me O Me CO2H Me L-Isoleucine, NOT L-Isoleucine, N-[[[(1R,2S)-1carboxy-2-methylbutyl]imino]methyl]- N-[[[(1R,2S)-1carboxy-2-methylbutyl]amino]methylene]- 4H-Imidazol-4-one, 3,5-dihydro5,5-dimethyl- 4H-Imidazol-4-one, 1,5-dihydro-5,5-dimethyl- And finally, under subrule 6.5, an R chiral center has priority over an S one: HN N NH2 Cl NOT H2N Cl N NH Cl HN N NHNH2 H2N N NNH2 NOT Cl S H H R S H H R 2H-Pyrrol-2-imine, 5-hydrazinyl- 2H-Pyrrol-2-one, 5-amino-, hydrazone 2H-Pyrrol-5-amine, 3,4dichloro-3,4-dihydro2-imino-, (3S,4R)- 2H-Pyrrol-5-amine, 3,4dichloro-3,4-dihydro-2imino-, (3R,4S)- HN Cl N N CO2H NOT Cl N N NH CO2H 1H-1,2,4-Triazole-3-carboxylic acid, 5-chloro- 1H-1,2,4-Triazole-5-carboxylic acid, 3-chloro- 123. Additive nomenclature embraces molecular structures whose several component parts are considered to be added together without replacement (substitution) of atoms (usually hydrogen). It includes coordination names (¶ 215), conjunctive nomenclature (¶ 124) and binary names of inorganic compounds (¶ 219). Examples: Copper, dichlorobis(methanamine)Benzeneethanol Sodium chloride (NaCl) The construction of additive names often involves indicated or added hydrogen (¶¶ 135, 136) in that part of the molecule known as the heading parent, the addition of hydro “substituents”, or the use of additive terms such as “oxide” or “sulfide” in the modification. In a few cases, the additive term becomes a part of the heading parent. Examples: 9(10H)-Anthracenone Naphthalene, 1,2,3,4-tetrahydroPyridine, 1-oxide Phosphine imide For salts and molecular addition compounds, see ¶¶ 192, 198. 124. Conjunctive nomenclature allows a cyclic molecular skeleton to be included as a part of the heading parent name even though the principal chemical group is separated from the ring by an acyclic chain. Larger molecules may be named thereby as heading parents and more compounds of similar structure can be collected at a given ring system name. Moreover, the major requirement of substitutive nomenclature, that the principal group be expressed in the heading parent as a suffix, is fulfilled. A conjunctive name is employed when any ring system (including a polyhedral borane) is attached by single bonds to one or more saturated acyclic hydrocarbon chains, each of which bears only one functional substituent corresponding to the principal chemical group of the compound. When a second or third such substituent is present on the chain, a conjunctive name may still sometimes be employed so long as the resulting index heading parent does not express more than a single function in each chain and other principles are not violated (see the final example below). It is always implied that the chemical functional group is at one end of the acyclic chain and the ring system is at the other. Examples Ph CH2 OH Subrule 6.2: The Isotope Subrule If a comparison of atomic numbers fails to reveal a difference in the tree diagrams, the CIP rule then compares mass numbers. Under subrule 6.2, at the first point of difference, the atom with the higher mass number has priority: Me Ph 15 Me N Ph NOT Ph 15 NH C N C NH Ph Ethanimidamide-N-15N, N,N ′-diphenylEt 13 Ethanimidamide-N ′-15N, N,N ′-diphenylEt CH3 NH C N Me NOT 13 CH3 N C NH Me Propanimidamide, N ′-methylN-(methyl-13C)- Propanimidamide, N-methylN ′-(methyl-13C)- H2N 35 N S S NH HN N S S NH2 NOT 35 3H-1,2,4-Dithiazol-1-35S-5amine, 3-imino- 3H-1,2,4-Dithiazol-2-35S-5amine, 3-imino- Subrules 6.3-6.5: The Stereo Subrules If a comparison of mass numbers also fails to reveal a difference, the CIP-based rule then compares stereo elements. For example, under subrule 6.3, a Z double bond has priority over an E one if the structure is X− CH=CH−Y, where X and Y are any covalently attached atoms or groups: NH Ph C N CH E CH Me CH Z CH Me NOT Ph C NH CH E CH Me N CH Z CH Me Benzenemethanol CH M e CH2 O H β α Cyclopentaneethanol, β-methyl- Benzenecarboximidamide, N ′-(1E)-1-propen-1-yl-N(1Z)-1-propen-1-yl- Benzenecarboximidamide, N-(1E)-1-propen-1-yl-N ′(1Z)-1-propen-1-ylPh CH 2 CO 2 H [1,1′-Biphenyl]-4-acetic acid Under subrule 6.4, a like pair of chiral centers (R,R or S,S) has priority over an ¶ 124 Pr | C H N H2 α Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Example: 3-Pyridinemethanamine, α-propyl6 10 3 CO 2 H 1 CO 2 H 1′ N 1 S 6′ Benzoic acid, 2,2′-thiobis- 3 S S C H C lC H2 CH2 CONH2 γ β α N 1 5 1,3-Dithiolane-2-butanamide, γ-chloro- α C H C lC O 2 H 1,3-Benzenediacetic acid, α1,α3-dichloroC H C lC O 2 H α′ In the example above, a simple one-part polyvalent radical, thio, was employed as a multiplier; other such radicals are oxy, -O-; methylene, -CH2-; 1,4phenylene, -1,4-C6H4-; imino, -NH-; nitrilo, -N=; and 1,3-disiloxanediyl, -SiH2OSiH2-. In general, any simple multivalent radical may be used as a multiplicative radical, and may itself be substituted; e.g., (methylimino), -N(CH3)-; (1-methyl-1,3-propanediyl), -CH(CH3)CH2CH2-. Multicomponent radicals may be used as multipliers if they contain a central one-part multivalent radical (simple, compound, or complex) around which all other multivalent radicals are so arranged that the sequence of atoms and bonds in each path is identical as one proceeds outwards. There is no restriction in the number of components that may comprise the total multiplying radical, so long as their use results in an unambiguous total name. Examples of permissible multiplying radicals: — CH 2 O CH 2 — [oxybis(methylene)] CH 2 − CH Cl— H N OH | C H C H2 CH2 α 1H-Pyrrole-2-methanol, α−(2− phenylethyl)- (the heading parent which expresses the preferred ring system, not the preferred acyclic chain, is chosen) — CH Cl − CH 2 − N − CH 2 − CH Cl— — O CH 2 CH ClO — | SiH | [nitrilotris(1-chloro-2,1-ethanediyl)] [(1-chloro-1,2-ethanediyl)bis(oxy)] 2 9 1 10 6 CHO | C HCH 2 CHO α3 C H 2 CHO α4 Bicyclo[4.3.1]dec-7-ene-3,4-diacetaldehyde, α3-(2-oxoethyl) (not Bicyclo[4.3.1]dec-7-ene-3-propanal, βformyl-4-(2-oxoethyl)-; the preferred heading parent expresses the maximum number of principal groups and, because it also expresses a ring system, is preferred to Butanedial) — SiH 2 CH 2 CH 2 C − SiH 2 — SiH2 | (1-propanyl-3-ylidynetetrasilylene) ([1,1′-biphenyl]-2,4′-diyldiimino) —NH NH— A conjunctive name is not permissible under the following conditions and the regular rules of substitutive nomenclature apply: 1) when a double bond joins the ring to the functional acyclic chain; 2) when a conjunctive index parent would express two or more functional groups in a single acyclic chain; 3) when the acyclic chain is unsaturated, or contains hetero atoms; and 4) when a conjunctive name would fail to express the maximum number of principal chemical groups. Examples: C H C O2 H The requirement for total symmetry in multiplication allows the use of “ylidene” in combination with other bivalent radicals. Η C H 2C C 2 CH2 (cyclobutylidenemethylene) || — C— Acetic acid, 2-cyclopropylidene- CH 2 — Si — O 5 1 || (methylenesilylene) C H (O H )2 Methanediol, 1-(2-furanyl)- Enclosing marks are used to distinguish certain combinations of multivalent radicals which would otherwise be ambiguous. — C − O − C— [oxybis(cyclopropylidenemethylene)] O C H = CHCH 2 NH 2 2-Propen-1-amine, 3-(2-benzofuranyl)- — CH 2 — C— O — C— CH 2 — [oxybis[(cyclopropylidene)(methylene)]] Examples of combinations of multivalent radicals which are not used as multipliers: N H C O2 H Carbamic acid, N-cyclopropyl— CH 2 N H — —O — CH 2 CH = N CH 2 C H = S— — CH Cl CH 2 PH CH C l C H2 — OH C H 2 OH 1,4-Naphthalenediol, 2-(hydroxymethyl)- — CH 2 O O — OH 125. Multiplicative nomenclature employs polyvalent radicals by which a multiplicity of occurrences of an index heading parent in a compound may be expressed. The naming of multiplying radicals is accomplished by citing first the central unit. This is followed by a prefix, e.g., “di” or “bis”, denoting the number of “radial” series generated by the central unit. The remaining terms of the name, in the form of radicals, are cited in appropriate enclosing marks as necessary. The entire multiplying radical is set off by further enclosing marks, 11 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Example: 1′ 2′ 2 1 ¶ 128 which are preceded by locants “placing” the radical at the proper point of attachment on each index heading parent. Multivalent radicals other than central units are numbered (if there is a choice) from the heading parents towards the center of the complete radicals, and the locant relating to the position closest to the heading parent is cited last. Examples: —C H C l C H 2 O C H 2 CHCl— 1 1 6 2 2 1 1′ 6′ H O CH 2 C H 2 O CH 2 S i H 2 O Si H O Si H 2 C H 2 O CH 2 C H 2 O H | O Si H2 C H2 O CH2 CH2 O H [oxybis(1-chloro-2,1-ethanediyl)] (dithiodi-4,1-phenylene) (selenodi-2-propene-3,1-diyl) [methylenebis(1,3,5-triazine-6,2,4triyl)] (the 2- and 4-positions are equally close to the heading parent and are therefore cited in normal sequence) S—S Ethanol, 2,2′-[[3-[[[(2-hydroxethoxy) methyl]silyl]oxy]-1,5-trisiloxanediyl]bis(methyleneoxy)]bis- (not Ethanol, 2,2′,2′′-[silylidynetris(oxysilylenemethyleneoxy)]tris-) 126. Radicofunctional nomenclature is used by CA in only a few cases, for disulfides, hydroperoxides, and peroxides (¶¶ 200, 196). Radicofunctional names express the compound type, e.g., “peroxide,” usually as a separate word. When inverted, the substituents are not followed by a hyphen unless multiplicative nomenclature (¶ 125) is used with Hydroperoxide; e.g., Disulfide, ethyl methyl; Hydroperoxide, 1-methylethyl; Hydroperoxide, cyclohexylidenebis-. 127. Replacement nomenclature (“a” nomenclature) is used for certain heterocyclic ring systems (¶ 146) and also, sometimes, for heteroorganic acyclic compounds. This nomenclature is limited to cases in which carbon atoms have been replaced in chains and rings by nonmetals and/or elements of which the hydrides are CA index heading parents, i.e., P, As, Sb, Bi, Si, Ge, Sn, Pb, and B. Requirements for its use in expressing acyclic chains are as follows: (a) A minimum of four hetero units must be present, none of which may be all or a part of a functional chemical group to be expressed in the index heading parent as the preferred functional compound class (i.e., as a functional suffix or as a functional index compound such as Carbonic or Phosphonic acid). A hetero unit is defined as an isolated hetero atom or a series of consecutive hetero atoms, alike or different, that may be expressed as a unit, such as by a bivalent radical name. Examples: -S- (thio); -S-S- (dithio); -N=N- (1,2-diazenediyl); -SiH2-O-SiH2-(1,3-disiloxanediyl); -SiH2-NH-SiH2-(1,3-disilazanediyl). The above are all single hetero units, but -HP-NH-, -S-O-, and -OSiH2-O-, are not. (b) The “a” name must not be lower in order of precedence than the name obtained by regular substitutive nomenclature, i.e., it must express at least as many principal functions of at least equal rank. (c) All hetero atoms must be in their standard valency state, or else the abnormal valency must be expressible unambiguously by use of “oxide,” etc., terms. (d) The chain may be terminated only by C, P, As, Sb, Bi, Si, Ge, Sn, Pb, or B. Acyclic “a” nomenclature is employed for organic chains containing silicon or metal atoms, polyesters, anhydrides, amides, polyamides, polyalkylene glycols, and condensed carbonic acid derivatives. It is not used for peptides or polymers, or (if it can be avoided) for chains containing no carbon atoms. Otherwise, if the above criteria are met, an “a” name is always selected. 128. Replacement prefixes for the elements most frequently found in carbon chains are set out in descending order of precedence in Table I. (The order is the reverse of that shown in ¶ 215 for coordinated elements.) TABLE I REPLACEMENT PREFIXES IN DESCENDING ORDER OF PRECEDENCE Element Oxygen Sulfur Selenium Tellurium Nitrogen Phosphorus Arsenic Antimony Bismuth Silicon Germanium Tin Lead Boron Substitutive Valence II II II II III III III III III IV IV IV IV III Prefix Oxa Thia Selena Tellura Aza Phospha Arsa Stiba Bisma Sila Germa Stanna Plumba Bora — C Η 2 C Η = C H Se CH = CHCH 2 — 1 2 3 3 2 1 1 1′ 6′ 5′N N 3N 6 CH 2 N N3′ N5 Carbonyl groups which are part of carbon chains are expressed as oxo substituents; chalcogen, imino, and hydrazono analogs are expressed as thioxo, selenoxo, telluroxo, imino, and hydrazono substituents. Examples: —C H2 N H C O C H 2 C ONHCH2 — 1 2 3 [(1,3-dioxo-1,3-propanediyl)bis(iminomethylene)] (1,2-dioxo-1,2-ethanediyl) —C O C O — —C H2 C ( = N H ) 1 2 C( =ΝΗ) CH2 — 2′ 1 [1,4-phenylenebis(2-imino-2,1ethanediyl)] When carbonyl groups and their analogs are not part of a larger acyclic carbon chain, the names carbonyl, carbonothioyl, carbonimidoyl, etc., are employed. Examples: 1 6 1′ 6′ CO (carbonyldi-4,1-phenylene) (carbonimidoyldiimino) [1,4-phenylenebis(carbonothioylimino)] —N HC ( = N H ) N H— —N H C S CSNH— Valid multiplying radicals are used only when the entire compound is symmetrical around the central unit of such a radical; i.e., the radical must be attached to the heading parent by bonds of the same type (single, double, or triple) and at equivalent positions, and this parent must be identical with regard to positions of principal groups (and their functional derivatives) and other substituents. Whether or not such other substituents are present, the terms “bis,” “tris,” etc., are employed after the multiplying radical, not “di,” “tri,” etc. If other substituents are present, they are cited as regular substitutive radicals after an opening bracket (which, perforce, is left unclosed). Examples: 1 N Cl 6 N S 1′ 6′ Cl Pyridine, 3,3′-thiobis[6-chloro- (not Pyridine, 5,5′-thiobis[2-chloro-; multiplicative radicals are given lowest locants) (The uninverted form of this name is 3,3′-Thiobis[6-chloropyridine].) Me H2 N Me 6′ 1′ 1 NH2 6 C = CH 1′′ 6′′ NH 2 Benzenamine, 3,3′,3′′-(1-ethenyl-2-ylidene)tris[6-methyl- Me The principles of multiplicative nomenclature are applied only after the index heading parent has been chosen, and after other principles, e.g., centrality (¶ 138), have been applied. When more than one multiplicative name is possible, that one is used which multiplies the greatest number of index heading parents, and then, if a choice is still necessary, that one which appears earliest in the alphabetic sequence of index entries. The number of occurrences of the parent is not increased by arbitrary breaking of the skeleton from which the multiplying radical is derived. The replacement prefixes are placed in descending order of precedence ahead of the name of the carbon skeleton with locants to indicate the positions of the atoms replaced. Lowest locants are assigned to functional groups if present, otherwise to the hetero atoms. Replacement nomenclature is also employed for acyclic substituent prefixes (radicals) when the above requirements are fulfilled. In this case, lowest locants are assigned to free valency positions; i.e., the “a” names are based on the carbon chain radical names, but the free valency locant (“1”) is always cited. Examples: CH3 − O − CH2 − CH2 − O − CH2 − CH2 − O — 14 13 12 6 5 11 4 10 3 9 2 8 1 7 ~~~ — CH 2 − CH 2 − N H − CH 2 − CH 2 − C Η 2 − O H 7,10,13-Trioxa-4-azatetradecan-1-ol ~~~ ¶ 128 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 12 (C H 2 ) 3 − S − (C H 2 ) 3 − O − CH 2 − CH 2 − CH 2 − SH 8 4 3 2 1 | O 12 | 16 20 21 22 23 (C H 2 ) 3 − S − ( C H 2 ) 3 − O − CH 2 − CH = CH 2 4,12,20-Trioxa-8,16-dithiatricos22-ene-1-thiol C H 3 − N H − C H 2 − C H 2 − NH − CH 2 − CH 2 −ΝΗ− CH 2 1 2 3 4 5 6 7 er by ≡N is denoted by nitrido. Peroxy acids are named by use of the affixes peroxo, (thioperoxo), and (dithioperoxo). These affixes are combined, in alphabetical order, with the functional suffix of compound names based on molecular skeletons. The systematic names Benzenecarboxylic, Ethanoic, and Methanoic acids, not the trivial names Benzoic, Acetic, and Formic acids, are used as the parents for functional replacement nomenclature. Examples: M e CS 2 H C H 3 − N H − C H 2 − C H 2 − NH − CH 2 − CH 2 − NH − CH 2 14 13 12 11 10 9 8 Ethane(dithioic) acid (not Acetic acid, dithio-) Benzenecarboximidic acid (the tautomeric Benzamide is preferred, except for esters and anhydrides; see ¶ 122) Benzenemethanesulfonohydrazonimidic acid (derived from the conjunctive name Benzenemethanesulfonic acid) Ethane(dithioperoxoic) acid 3,6,9,12-Tetraazatetradecane1,14-diamine, N1,N14-dimethyl- PhC( =NH) OH OH O C H 3 − C H − C − O − C H − C − O − CH − C − O − CH − C − O − CH − COOH 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 | || CH3 O | || CH 3 O | || CH3 O | || CH3 | NNH 2 || CH2 S − O H || NH 3,6,9,12-Tetraoxapentadecanoic acid, 14-hydroxy-2,5,8,11tetramethyl-4,7,10,13-tetraoxoO C H 3 − C H 2 − O − (C H2 − CH 2 − O) 3 − CH 2 − CH 2 − O − C − ( CH 2 ) 10 − CH 3 12 2 1 O || CH 3 CSSH || Dodecanoic acid 3,6,9,12-tetraoxatetradec-1-yl ester CH3 + In replacement names from phosphorus and arsenic functional parent compounds (¶ 197), all the affixes except hydrazono may be employed as part of the suffix. For Carbonic acid and its relatives (¶ 183) all but hydrazido and nitrido may be used. Examples: C l P ( O ) ( O H )2 Phosphorochloridic acid Arsonamidous acid, As-methylPhosphorothioic triamide Carbonohydrazonic acid Carbonodiperoxoic acid N 12 C H 2 − N H − CH 2 − NH − CH 2 − NH − CH 2 − NH − CH 2 9 8 7 6 5 4 3 2 1 3 4 3 CH 3 1 2 N 4 + MeAs (NH2) OH 2I − P(S)(NH2)3 (HO)2 C=NNH2 ( H O O ) 2 CO Quinolinium, 2,2′-(2,4,6,8-tetraazanonane-1,9-diyl)bis[1methyl-, iodide (1:2) O C − N H − CH 2 − CH 2− S − CH 2 − CH2 − O − CH2 − CH2 − NH − C O O H 12 11 10 9 8 7 6 5 4 3 2 1 || 5-Oxa-8-thia-2,11-diazadodecanoic acid, 12-oxo-12-phenyl- In replacement names from other mononuclear acids and from condensed nuclear acids (anhydrides), the affixes are used as nondetachable prefixes cited at the beginning of the heading parents. Because multiplicative prefixes are rarely used for thio and other chalcogen prefixes, ambiguity is resolved by synonym line formulas in the boldface index headings. Examples: O C H 3 − O − C H 2 − O − C H 2 − O − CH 2 −Ο− CH 2 − CH 2 −Ο COOH HO−P−NH−P−O−P−OH | | | OH OH OH H O 2 CN H CO 2 H || O || O || Imidotriphosphoric acid Imidodicarbonic acid Benzoic acid, 4-(3,5,7,9-tetraoxadec-1-yloxy)O CH3 O CH3 O CH3 O O O O || H O − S − Se H || O S S || || H S − C − S − C − SH Selenosulfuric acid (H2SO3Se) || P − C H 2 − CH 2 − C − NH − CH 2 − NH − C − C = CH 2 || || Thiodicarbonic acid ([(HS)C(S)]2S) P − C H 2 − CH 2 − C − NH − CH 2 − NH − C − CH 2 CH3 O O || O || O || Nondetachable prefixes are used in a few other cases. Examples: ClSO 3 H S( O ) ( = N H ) ( N H 2 ) 2 ( H 2 N ) 2 CS H 2 N SH Phosphonic acid, P,P′-(8-methylene3,7,10,14-tetraoxo-4,6,11,13tetraazahexadecane-1,16-diyl)bis-, P,P,P′,P′-tetramethyl ester 129. Replacement nomenclature for functions is a method of describing the replacement of hydroxyl and oxo functional groups by nitrogen, chalcogens, halogens, or halogenoids such as isocyanato. The replacement may be carried out in substituent suffixes, e.g., -thioic acid from -oic acid; in substituent prefixes, e.g., carbonimidoyl (¶ 134) from carbonyl, and phosphinothioyl from phosphinyl (¶ 197); and in functional parent compounds (¶ 130), e.g., Phosphonimidodithioic acid from Phosphonic acid. Replacement of hydroxyl in compounds and radicals is denoted by the following affixes (the final “o” is often elided): amido (for -NH2), azido (for -N3), chlorido (for -Cl) (and similarly for other halo atoms), cyanatido (for -OCN), hydrazido (for -NHNH2), isocyanatido (for -NCO), (isothiocyanatido) (for NCS), and (thiocyanatido) (for -SCN). Seleno and telluro analogs are named analogously. Replacement of oxo is denoted by the affixes hydrazono (for =NNH2), imido (for =NH), thio (for =S), etc. Replacement of a hydroxyl and an oxo togeth- A c O SA c E t O SH Chlorosulfuric acid Imidosulfamide Thiourea Thiohydroxylamine Thioperoxide, diacetyl Thiohydroperoxide, O-ethyl 130. Substitutive nomenclature, in which hydrogen atoms are replaced by other atoms or chemical groups, is of paramount importance among nomenclature systems because of its versatility. Substitutive parent compounds, which are real or hypothetical compounds whose names imply the presence of replaceable hydrogen atoms, are of two kinds: (a) Functional parent compounds have names which express a chemical function but are not based on a molecular skeleton. Substitutive examples include Arsonic acid, Imidodicarbonic acid, Carbamic acid and Phosphonamidic chloride. Their substituents are always expressed as prefixes, never as suffixes. 13 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Examples: M e ( CH 2 ) 4 O — ClCO — Ph O 2 C— ( M e O ) 2 P( O ) — M e O CS— ¶ 133 (b) Molecular-skeleton parent compounds are nonfunctional. They are chains or rings of atoms with only hydrogen atoms attached and possessing names which express or imply the substitutive valency and bonding of the skeletal atoms. (Methane and monoatomic hydrides of the Group IVA elements and the Group VA elements (except nitrogen) are treated as molecular skeletons.) Examples include Ethane, Distannane, Diazene, 3,6,9,12,15-Pentaoxaheptadecane, Cyclohexane, Morpholine, Phosphine, and Stannane. They are transformed into index heading parents by appending, as a suffix, the substituent which represents the principal functional group of the compound; other substituents are expressed as prefixes. 131. Substituent suffixes of molecular-skeleton parent compounds are chosen to represent the principal chemical functional group (or groups) in accordance with the order of precedence of compound classes (¶ 106). When no suffix is available to represent the preferred compound class, either a substitutive functional parent compound (¶ 130) is used as a heading parent, or another system of nomenclature, e.g., coordination or radicofunctional, is adopted. Examples: E tP(O ) (O H ) 2 (pentyloxy) (chlorocarbonyl) (phenoxycarbonyl) NOT (pentylhydroxy) NOT (chloroformyl) NOT (phenylcarboxy) (dimethoxyphosphinyl) NOT (dimethylphosphono) (methoxythioxomethyl) NOT (methoxycarbonothioyl) Phosphonic acid, P-ethyl-(Phosphonic acid is a functional parent compound.) Sulfur, trifluorophenyl-, (T-4)(a coordination name) Peroxide, bis(trifluoromethyl) (a radicofunctional name) P hS F 3 F3COOCF3 The particular suffixes used for various classes of compounds in descending order of precedence from acids through imines (¶ 106) are described in the sections of this Guide dealing with these classes. Only one class may be expressed as a suffix in a single index heading parent; less preferred classes are denoted by prefixes. Multiplicative prefixes are employed to indicate the number of principal groups present. Examples (in descending order of compound classes): C O2 H COCl E tC O 2 H Benzoic acid, 2-(chlorocarbonyl)Propanoic acid 2-Propanesulfonic acid 2-Pentanone, 4-thioxo- All compound radicals are enclosed in parentheses. Simple radicals are so enclosed when two locants of like type fall together; e.g., Benzoic acid, 3-(4pyridinyl)-; for clarity, when one locant has been omitted in the name of an indefinite compound; e.g., 1,2-Propanediol, 3-(thienyl)-; and when “bis” or “tris” has been employed to remove ambiguity (see ¶ 110); e.g., tris(decyl), bis(benzanthracenyl), bis(azepinyl). Brackets are used in complex radicals, e.g., [2-(dimethylamino)ethoxy]. Spaces in a name often permit the dropping of one set of enclosing marks around radicals in substituents and modifications; e.g., Disulfide, 2-chloroethyl ethyl; Propanoic acid, 2-ethylbutyl ester. 133. Compound radicals. Selection of names for compound radicals is usually simple, but, when chain branching is present, can sometimes become perplexing. The following rules are successively applied; ((a) through (e) lead to selection of the preferred parent radical, (f) through (h) to a particular occurrence of this radical). (a) Greatest number of acyclic hetero atoms. (b) Greatest number of skeletal atoms. (c) Greatest number of most preferred acyclic hetero atoms (see Table I, ¶ 128). (d) Greatest number of multiple bonds. (e) Lowest locants in the simple radical for replacement atoms in “a” names, then for multiple bonds of any kind, and finally for double bonds. (f) Greatest number of substituents attached to the simple radical. (g) Lowest locants for such substituents. (h) Earliest index position of the total radical as it appears within the index name. Examples (the italic letters on the left indicate the particular rule (above) that is exemplified): (a) CH 2 − CH 2 − CH 3 | CH 3 − O − CH − O − CH 2 − CH 2 − O − CH 2 − CH 2 − Ο − CH 2 − CH 2 — 11 10 9 8 7 6 5 4 3 2 1 1 MeC H MeSO 3 H 2 12 MeC O C H 2 C SMe 1 5 (10-propyl-3,6,9,11-tetraoxadodec-1-yl) (a) SiH3 | H3 Si − O − SiH — 3 2 1 H O S iMe 2 O S iMe 2 OH 6 1,3-Disiloxanediol, 1,1,3,3-tetramethyl(b) Benzenemethanol, 2-hydroxy(b) (1-silyl-1-disiloxanyl) 1 C H 2OH OH 4 CH3 − C = O | CH 3 − CH = CH − CH — 3 2 1 (1-acetyl-2-buten-1-yl) CH3CH2NH2 Ethanamine (b) 3 CH 2 || CH 3 − CH 2 − C— 2 1 (1-methylenepropyl) [(1-propylpentyl)oxy](not (1-butylbutoxy))(the selection principles are applied before elision is performed; another example follows) ([1,1′-biphenyl]-4-yloxy)(not (4phenylphenoxy)) O || C— 132. Substituent prefixes (commonly called “radicals”) are employed to denote atoms and chemical groups attached to an index heading parent. The following substituents are never expressed as suffixes; they may be termed “compulsory” or “mandatory” prefixes: astato (At-), astatyl (AtO2-), azido (N3-), bromo (Br-), chloro (Cl-), chlorosyl (OCl-), chloryl (O2Cl-), diazo (N2), fluoro (F-), iodo (I-), iodosyl (OI-), iodyl (O2I-), isocyanato (OCN-), isocyano (CN-), nitro (O2N-), aci-nitro ((HO)(O)N=), nitroso (ON-), and perchloryl (O3Cl-). In addition, all thio, sulfinyl, and sulfonyl radicals, (RS-), (RS(O)-), and (RS(O)2-), and their seleno and telluro analogs, are mandatory substituent prefixes; so are hydrocarbon radicals and other radicals derived from molecular skeletons, e.g., ethyl, furanyl, disiloxanediyl, when attached to a more preferred heading parent. Radicals may be simple, compound, or complex. A compound radical is made up of two or more simple radicals, e.g., (chlorothio), (diaminomethyl). A complex radical is composed of a simple radical to which at least one compound radical is attached; e.g., [(chloromethyl)amino], [1-(trichloromethyl)-2buten-1-yl]. In these examples, amino and 2-buten-1-yl are parent radicals, and methyl (in both cases) is a subsidiary radical. This procedure may be repeated indefinitely. (Chlorothio) is obtained by addition of the two components, (aminomethyl) by substitution of methyl by amino. Substitution is the preferred method when a substitutive simple radical is available; e.g., (aminomethylene) is (NH2CH=), not (NH2CH2-). Substitution in certain radicals, including the following, is not permitted: hydroxy, mercapto, selenyl, telluryl, hydroperoxy, sulfeno, formyl, carboxy, sulfo, phosphono, and carbonothioyl. CH 2 − CH 2− CH 3 | CH 3 − ( CH 2 ) 3 − CH − O — 5 4-2 1 (b) —O (b) ([1,1′-biphenyl]-4-ylcarbonyl)(not (4-phenylbenzoyl))(the simple radical benzoyl is retained for (phenylcarbonyl) only when the rules lead to this name) (4-chlorobenzoyl)(not [(4-chlorophenyl)carbonyl]) (b) Cl CO — (b) 1 6′ 1′ 3′ 1′′ [1,1′:3′,1′′-terphenyl]-5′-yl ¶ 133 ( c) S − S iH 3 | H 3 S i − O − S iH — Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 H 2 N CH 2 CO — ClCO CO — 14 [1-(silylthio)-1-disiloxanyl] (2-aminoacetyl)(glycyl is permitted in peptide nomenclature) (2-chloro-2-oxoacetyl) (acetylamino) [(1-oxopropyl)amino] (4-imino-4-phenyl-1-thioxobutyl) [(1-iminoethyl)amino] 1 ( c) 14 S − CH 2 − CH2 −Ο− CH2 − CH3 | C H 3 − C H 2 − O − CH 2 −Ο− CH 2 − CH − CH 2 − O − CH 2 − CH 2 −Ο− CH 2 − CH 2 — 13 12 11 10 9 8 7 6 5 4 3 2 1 AcNH— E tCO N H — Ph C( = N H ) ( CH 2 ) 2 CS— 4 [8-[(2-ethoxyethyl)thio]-3,6,10,12tetraoxatetradec-1-yl] (d) C H3 − C = O | C H2 = C H − C H — M e C( = N H ) N H — (1-acetyl-2-propen-1-yl) Isolated carbonyl radicals, other than carboxy, are expressed as carbonyl (as a doubling radical, or when both free valencies are attached to a single atom), formyl (if unsubstituted), benzoyl (if attached to a phenyl group which is not itself attached to another phenyl), or as a compound radical in which carbonyl is the parent. Examples: H O 2 CCO — H 2 N CO — ClCO — — N H CO N H — HCO CO — (d) C H 3− C H 2− C ≡ C − CH = CH | C H 3 − C H = C H − CH = CH − CH 2 − CH— 7 6 5 4 3 2 1 [1-(1-hexen-3-yn-1-yl)-3,5-heptadien-1-yl] (double bonds are preferred over an equal number of triple bonds) ( e) C H 3 − O − CH 2 − CH 2 − O − SiH 2 −Ο− CH 2 − CH 2 | C H 3 − C H 2 − Ο − CH 2 − CH 2 −Ο− SiH 2 −Ο− CH 2 − CH − CH 2 — 10 9 8 7 6 5 4 3 2 1 (carboxycarbonyl) (aminocarbonyl)(not carbamoyl) (chlorocarbonyl)(not chloroformyl) (carbonyldiimino) (4-formylbenzoyl) 11 [2-(3,5,8-trioxa-4-silanon-1-yl)4,6,9-trioxa-5-silaundec-1-yl] ( e) C H 3 − C H2 − C ≡ C − CH 2 − CH = CH | C H 3 − C H 2 − C H 2 − CH = CH − C ≡ C − CH − CH 2 — 9 8 7 6 5 4 3 2 1 OC (3-carbonylcyclohexyl) Replacement analogs of isolated carbonyl groups (other than chalcogen analogs of carboxy) are named as thioxo, imino, etc., derivatives of methyl, unless both free valencies are attached to a single atom, or the radical is being used multiplicatively (¶ 125), in which case carbonimidoyl, carbonohydrazonoyl, carbonothioyl, etc., are employed. Examples: H S 2 CN H — H CS H O C( = N H ) — H 2 N C( = N H ) N H — HN=C=N — CO — [2-(1-hepten-4-yn-1-yl)-5-nonen-3-yn-1-yl] (e) C H2 = C H − C ≡ C − CH2 | H C ≡ C − C H = C H − CH 2 − CH— 5 4 3 2 1 6 [1-(4-penten-2-yn-1-yl)-3-hexen5-yn-1-yl] (f) CF 3 | CH3−C−CH2— | CF 3 CH 3− CH 2 | C H 2 − CH 2 − CH— CH 3 − CH − CH3 | O CH2 || | C H 3 − C H 2 − C − CH— 3 2 1 [3,3,3-trifluoro-2-methyl-2-(trifluoromethyl)propyl] [(dithiocarboxy)amino] [4-(thioxomethyl)benzoyl] (hydroxyiminomethyl) [(aminoiminomethyl)amino] (carbonimidoylamino) (f) (1-ethyl-3-phenylpropyl)(not [1-(2phenylethyl)propyl]) [1-(2-methylpropyl)-2-oxobutyl] (not [3-methyl-1-(1-oxopropyl)butyl]) (g) 4 (g) C H3 | C H3 − C H − C H — | B rC H 2 − C H 2 [1-(2-bromoethyl)-2-methylpropyl] (not [3-bromo-1-(1-methylethyl)propyl]) 135. Indicated hydrogen is a designation comprising a locant followed immediately by an italic capital H placed before a ring system name to express the position of each of the saturated atoms necessary for formation of a definable, stable ring system. Thus, Pyrrole always has one saturated atom (an atom not connected to either of its neighbors by a double bond) and, according to the position of this atom, the compound is named as follows: 1 (h) C H3 | C H3 − C H − C H — | C H3 − C = O (1-acetyl-2-methylpropyl)(not [1(1-methylethyl)-2-oxopropyl]) H N 5 1 5 1 N 5 N 134. Carbonyl radicals which form part of a carbon chain are expressed by oxo substituents on the chain; the only exceptions are carboxy (-C(O)OH) and acetyl (-C(O)CH3) radicals. The latter is used whenever (1-oxoethyl) would otherwise be called for. All chalcogen, imido and hydrazinylidene analogs of carbonyl in a chain are treated similarly by use of thioxo, selenoxo, telluroxo, imido, and hydrazinylidene radicals, except for chalcogen analogs (but not imido, etc., analogs) of carboxy; e.g., (HS(S)C-) is named (dithiocarboxy). Replacement analogs of acetyl are named (1-iminoethyl), (1-thioxoethyl), etc. Acyl radical names other than acetyl and benzoyl, e.g., propanoyl, are not used for substituents; neither are amido radicals, e.g., acetamido. Examples: HO2CCH2— HCOCH2— E tC O — C lC O C H 2 — 1H-Pyrrole 2H-Pyrrole 3H-Pyrrole In the Chemical Substance Index only a single illustrative structural diagram is provided for each ring system, viz., the diagram which shows the saturated center(s) in the lowest-numbered nonangular position(s). Tetrahydropyrrole has the trivial name Pyrrolidine: dihydropyrroles are named as derivatives of that pyrrole which has indicated hydrogen at the lowest numberedpositionconsistentwiththestructure.Othermonocyclicheterosystems are named in the same way. Hydrogen on a single ring atom between two bivalent hetero atoms is not indicated in the name. Examples: H N 5 1 (carboxymethyl) (2-oxoethyl)(not (formylmethyl)) (1-oxopropyl) (2-chloro-2-oxoethyl) 1H-Pyrrole, 2,5-dihydro- (not 2H-Pyrrole, 1,5-dihydro-) 15 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 1 7a 3 4 1 ¶ 136 O 6 2H-Pyran, tetrahydro- (not 4HPyran, tetrahydro-) 3aH-Indene-3a-carboxylic acid, 1,4-dihydro- CO 2 H 1 10a S 6 S3 4H-1,3-Dithiin (not 2H,4H-1,3Dithiin) 9 O 6 10 O 4 4H,6H-Benzo[1,2-b:5,4-b′]dipyran4,6-dione, 2,3,7,8-tetrahydro- The lowest locants for nonangular positions of fused ring systems are normally cited for indicated hydrogen. Example: 1 7a 3 4 5 O 1 O 4H-Indene, 3a,5-dihydro- (not 3aH-Indene, 4,5-dihydro- or 5H-Indene, 3a,4-dihydro-) 7 O 9 8a 3a O Indicated hydrogen is assigned to angular or nonangular positions when needed to accommodate structural features, e.g., a bridge, spiro junction or ring-assembly junction, if that form of the ring system can exist. Examples: H N 1 5 4H-3a,7-Methanoazulene-4,9dione, 1,2,3,7,8,8a-hexahydro(not 1H-3a,7-Methanoazulene-4,9(7H)-dione, 2,3,8,8a-tetrahydro-) (the ketone function on the bridge is ignored in choosing indicated hydrogen to accommodate the single remaining function) 2 1 8a S 4 NH N (2,3-dihydro-4H-1,2,4-benzo thiadiazin-4-yl)(not 2H-1,2,4benzothiadiazin-4(3H)-yl) 6 8 7a 3a,6-Methano-3aH-indole, 1,4,5,6-tetrahydroO 1 8a 3a O 4 1 11a 11b 7 8 6′ 1′ 3 4 6 5 Spiro[7H-benz[de]anthracene7,1′-cyclohexane], 4,5,6,6atetrahydro- O O 2H-1-Benzopyran-4,5,8(3H)-trione, 6,7-dihydro- (not 4H-1-Benzopyran-4,5,8-trione, 2,3,6,7-tetrahydro-) 7a H N 1 Ν 3 2 2′ Ν H N 1′ 7′a 3′ 4′ 2,2′-Bi-2H-indazole, 1,1′,3,3′tetrahydro- 4 When a bridge requires hydrogen to be added, but indicated hydrogen of the parent system cannot be used for that purpose, the lowest locant, or a locant to accommodate a principal function, is chosen for the parent ring, and additional indicated hydrogen is cited in the name ahead of the bridge designation. Example: 4H-3a,6-Methano-3H-1,2-benzoxathiole, tetrahydro- (3aH-1,2Benzoxathiole cannot exist; the lowest available locant is therefore cited and the “extra” hydrogen for the bridge cited as additional indicated hydrogen, not in the “added” hydrogen form (see below), 3a(4H),6Methano....) 136. Added hydrogen is hydrogen which is added to a ring system in the same operation as, but in a position different from, hydrogen added to accommodate structural features of a ring system, e.g., bridges, or spiro or ring-assembly junctions, or principal groups of a heading parent, or free valencies of a parent radical, when indicated hydrogen (¶ 135) is either not needed for the ring system itself or cannot be chosen to accommodate them. It differs from indicated hydrogen in being expressed as a locant and capital italic H in parentheses immediately following the locant for the principal function or other accommodated structural feature, e.g., “2(1H)-.” Use of added hydrogen permits expression of a principal function, etc., in a heading parent instead of as a substituent. Thus, 1-Naphthalenone cannot exist without partial hydrogenation of the naphthalene ring system; a name such as Naphthalene, 1,2-dihydro-1-oxo- violates the rule that the principal function be expressed as a suffix. Therefore, two hydrogen atoms are added in one operation to provide the name 1(2H)-Naphthalenone, in which the “added” (or “extra”) hydrogen is at the 2position. O 8a 1 1 6 8 3a 7a O S2 5 4 After structural requirements have been met, indicated hydrogen is chosen to accommodate principal functions or (in a cyclic radical) free valencies, so long as the number of indicated hydrogens cited equals or exceeds the number of principal groups or free valencies that must be accommodated. For the usual case of a ring which requires a single indicated hydrogen for its existence, a single principal function or free valency is accommodated, but a polyfunctional compound is named at the ring system with lowest nonangular indicated hydrogen. (Functions on bridges are disregarded in applying this rule.) Examples: 1 When principal functions or free valencies require added hydrogen, it is assigned to the lowest-numbered available angular or nonangular position; e.g., 1(2H)-Naphthalenone, 3,4-dihydro- (not 1(4H)-Naphthalenone, 2,3-dihydro-); 2(4aH)-Naphthalenone, 5,6,7,8-tetrahydro-. When the ring system requires indicated hydrogen and it cannot be assigned to accommodate a principal group or free radical, it has preference over added hydrogen for lowest locants. When a pair of principal groups, e.g., “-dione,” are expressed by a heading parent, added hydrogen is not cited unless necessary, it being understood that only sufficient hydrogen has been added to accommodate the functions. Examples: 8a 1 O 6 4H-Pyran-4-one, tetrahydro- 4a(2H)-Naphthalenecarboxylic acid, 1,3,4,5-tetrahydro(a 4a(1H)-isomer cannot exist) 5 4 CO 2 H O O 6 9a 2 H N 1 3 N (C H 2 ) 2 O H 6 5 2H-2-Benzazepine-2-ethanol, 1,3,4,5-tetrahydro- NH 4,6(1H,5H)-Pyrimidinedione, dihydro- O ¶ 136 H N 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 (3,4-dihydro-2(1H)-quinolinylidene) (not (1,4-dihydro-2(3H)-quinolinylidene)) O 16 8a 5 4 (6-chloro-2,5-dioxo-3-cyclohexen1-yl) Cl O 1 9a 3 9b 5 6 4 O 1H-Benz[e]indene-3,5(2H,4H )dione, 3a,9b-dihydro- 1 M e CH = CH C ≡ CCF 3 6 2-Hexen-4-yne, 6,6,6-trifluoro(double bond given preference over triple bond) O OH 1 6 1 O O 2H-Pyran-3(4H)-one, dihydro(3H-Pyran cannot exist) 8a CO 2 H 3 2-Azulenecarboxylic acid, 8-hydroxy-4,5-dimethyl- 4 Me O 8 9 10a 5 10 9a 1 Me 9,10-Anthracenedione (not 9,10(9H,10H)-Anthracenedione) 4 NHEt 1 3 4a O O 1 9a 9b 3 4 6 5 NMe2 O 1,3-Benzenediamine, N1-ethyl-N3,N3,4-trimethyl- (not 1,3Benzenediamine, N3-ethylN1,N1,6-trimethyl-; see ¶ 114) 1H-Benz[e]indene-1,2(3H)-dione (not 3H-Benz[e]indene-1,2-dione) (low numbering of indicated hydrogen is observed, even if added hydrogen must then be cited) Me Br 6 N 1 4 Benzene, 1-bromo-3-nitro- (not Benzene, 3-bromo-1-nitro-) (2,3-dihydro-1,4-pyrazinediyl) (not (1,4(2H,3H)-pyrazinediyl)) NO2 N Added hydrogen cited when hydrogen is required elsewhere for spiro and ring-assembly junctions is assigned (in descending order of preference) (a) to accommodate another spiro or ring-assembly junction, (b) to accommodate principal groups or free valencies, or (c) to lowest-numbered available positions. 137. Numbering of molecular skeletons. Lowest locants for a set of principal groups, substituents, etc., are always preferred. The set, e.g., 5,6,1,2,1 is compared with another (alternative) set, e.g., 1,2,5,6,5, by rearranging them both in ascending numerical sequence: 1,1,2,5,6 and 1,2,5,5,6. The set which contains the lowest locant at the first point of difference when all sets are compared term by term is the lowest, i.e., 1,1,2,5,6 is lower than 1,2,5,5,6. Example: NO 2 8a 1 Cl 5 4 Naphthalene, 5-bromo-6-chloro1,2-dihydro-1-nitro- (not Naphthalene, 1-bromo-2-chloro-5,6-dihydro-5-nitro-) Br Lowest locants for various kinds of structural features in cyclic and acyclic molecular skeletons are assigned, in order, to: (a) hetero atoms (except for “a”-named radicals, see ¶¶ 127, 161); (b) indicated hydrogen; (c) principal groups or (for radicals) free valencies; (d) multiple bonds; (e) substituent prefixes; (f) the substituent prefix cited earliest in the name. Examples: C H 3 − O − C H 2 − C H 2 − O − CH 2 − CH 2 −Ο− CH 2 − CH 2 −Ο− CH 2 − CH 2 −Ο H 13 12 11 10 9 8 7 6 5 4 3 2 1 138. Index name selection. Most organic compounds have names based on molecular skeletons, e.g., Propanoic acid (from propane); 1,3-Dioxan-2amine (from 1,3-dioxane). Procedures for selecting the preferred name of this kind for index use are described in this section (see also ¶ 105). Selection of a heading parent name based on a molecular skeleton is made by successive application of the following principles until a decision is reached. (a) Greatest number of the principal chemical functional group. (b) Preferred atomic content of the molecular skeleton in accordance with the order of precedence of compound classes (¶ 106). The heading parent should express at least one occurrence of an atom appearing earliest in the following list: N, P, As, Sb, Bi, B, Si, Ge, Sn, Pb, O, S, Se, Te. (This principle is used to decide between a cyclic and an acyclic parent, but is not applied to choices between ring systems. When acyclic and cyclic skeletons of the same compound class are present, a cyclic parent is preferred.) ( c) Preferred ring system. The choice between ring systems for use as heading parents is based on the following criteria, applied successively until a decision is reached. The senior ring system should: (1) be a nitrogenous heterocycle; (2) be a heterocycle; (3) contain the largest number of rings; (4) be a cyclic system occurring earliest in the following list of systems; spiro, bridged fused, bridged nonfused (Von Baeyer), fused; (5) contain the largest individual ring (applies to fused carbocyclic systems); (6) contain the greatest number of ring atoms; (7) contain the greater number of ring atoms common to two or more rings (applies to Von Baeyer ring systems); thus is s e n io r to 3,6,9,12-Tetraoxatridecan-1-ol H O2 C 6 1 O 2H-Pyran-6-carboxylic acid, 3,4dihydro- (not 4H-Pyran-2-carboxylic acid, 5,6-dihydro-) 4 O || CH2=CH−C−CH3 3 2 1 3-Buten-2-one (not 1-Buten-3-one) (8) contain lowest locants for bridges; (9) contain the largest number of hetero atoms; (10) contain the most preferred hetero atom other than nitrogen, according to the order in Table I, ¶ 128, i.e., O, S, Se, Te, N, P, As, Sb, Bi, Si, Ge, Sn, Pb, B. (11) possess the most linear arrangement of rings (thus, Anthracene is senior to Phenanthrene); (12) possess the lowest locants for hetero atoms assigned according to the rules (¶¶ 146, 152); (13) express the lowest state of hydrogenation; thus, Benzene is preferred over Cyclohexane, Pyridine over Piperidine; (14) express the lowest locant for indicated hydrogen. Note: These criteria differ from those employed in selecting base components for fused systems (¶ 150). (d) Greatest number of acyclic hetero atoms. (e) Largest index heading parent. 17 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 (e) CH 2 || CH 3 − CH 2 − CH 2 − C − CH 2 − CH 3 6 5 4 3 2 1 ¶ 138 (f) Greatest number of most preferred acyclic hetero atoms, according to the order of precedence in ¶ 128, above; i.e., O, S, Se, Te, N, P, As, Sb, Bi, Si, Ge, Sn, Pb, B. ( g) Greatest number of multiple bonds. (h) Lowest locants in the heading parent successively for hetero atoms, principal groups (suffixes), all multiple bonds, double bonds. If the preferred heading parent occurs more than once in the total compound, further principles must be applied, as follows: (i) Centrality. For three or more occurrences of the heading parent, at least one of which must be nonterminal, the basis of the name is the central occurrence (or one of the central pair—both, when multiplicative nomenclature is permitted—if the total number is even) in the linear arrangement which comprises all or part of the maximum number of occurrences. (j) Maximum number of substituent prefixes. (k) Lowest locants for substituents on the heading parent. (l) Multiplication of heading parents; when there is a choice of multiplicative names, that one is chosen which multiplies the largest number of occurrences of the index heading parent. (m) Earliest index position of the total name. Examples (the italic letters on the left indicate the particular rules (above) that are exemplified): (a) 4 Hexane, 3-methylene- (not 1-Pentene, 2-ethyl-) (e) HO CH ( O H ) CH 2 O H β α 1,3-Benzenediethanol, β1, 5-dihydroxy- (see ¶ 124) ( CH 2 ) 2 O H (f ) H 3 SiO SiH 2 SiH 2 SSiH 3 3 21 Disiloxane, 1-disilathianyl- (g) CH 3 | CH 2 = C − CH = CH 2 1 2 1,3-Butadiene, 2-methyl- OH CH 2 − C H 2 − CH 2 − CH 2 − CH 3 C H 3 − C H − C H − C H 2 − OH 3 2 1 | | (g) 1,3-Butanediol, 2-pentyl- C ≡ C − CH 2 − CH 2 − O H | H O − CH 2 − CH = CH − CH 2 − CH − CH 2 − CH = CH − CH 2 − O H 9 8 7 6 5 4 3 2 1 (a) H O2 C CH( CO 2 H) CH 2 CO 2 H Butanedioic acid, 2-(4-carboxyphenyl)(h) (b) H O2 C NHNHCO 2 H 2 1 2,7-Nonadiene-1,9-diol, 5-(4-hydroxy-1-butyn-1-yl)- (double bonds are preferred over an equal number of triple bonds) Hydrazinecarboxylic acid, 2-(4carboxyphenyl)- O − CH2 − CH3 | CH 3 − O − CH 2 − CH − O − CH 2 − O − CH 2 − O − CH 2 − CH 2 − CO O H 9 8 7 6 5 4 3 2 1 10 11 12 (b) O S iH 2 SiH 3 Disilane, 2-furanylDiazene, phenyl- (not Benzenamine, N-imino-) (homogeneous hetero chains are never broken to obtain a higher function or more preferred parent) 4,6,8,10-Tetraoxadodecanoic acid, 9-(methoxymethyl)- (not 3,5,7,9-Tetraoxadodecan-12-oic acid, 4-(methoxymethyl)-) (b) PhN=NH (h) ΟΗ H O - CH2 - CH2 - CH 2 | | H O − CH 2 − CH 2 − CH 2 − CH 2 − CH − CH 2 − CH − CH 3 1 2 3 4 5 6 7 8 (b) (C H 2 ) 6 − CH 3 | C H − C OOH α 1 6 Benzeneacetic acid, α-heptyl(not Nonanoic acid, 2-phenyl-) 2-Pyridinecarboxylic acid, 5-(2carboxyhydrazino)- (the number of preferred hetero atoms in the cyclic and acyclic chains is disregarded) 1,7-Octanediol, 5-(3-hydroxypropyl)- (not 1,8-Octanediol, 4-(2-hydroxypropyl)-) (h) CH 2 − CH = CH − CH 2 − O H | H O − CH 2 − CH = CH − CH 2 − CH − CH = CH − CH 2 − CH 2 − O H 1 2 3 4 5 6 7 8 9 (b) N CO 2 H H O2 C N H N H (b) 1 O − CH 2 − CH 2 −Ο− CH 2 − C H 3 | C H 3 − Ο − C H 2 − C H 2 −Ο− CH 2 − CH 2 −Ο− CH − CH 2 − NHNH − CH 2 − CH 2 − CH 3 2 3 4 5 6 7 8 9 10 11 12 13 14 15 2,6-Nonadiene-1,9-diol, 5-(4-hydroxy-2-buten-1-yl)- (not 2,7Nonadiene-1,9-diol, 5-(4-hydroxy-1-butenyl)-) 2,5,8-Trioxa-11,12-diazapentadecane, 9-(2-ethoxyethoxy)( c) N NH OH N OH 3-Quinolinol, 2-(1,2-dihydro-2hydroxy-5-pyrimidinyl)- (i) Ph CH 2 CH2 Ph Benzene, 1,4-bis(phenylmethyl)- (d) C H 2 − C H 2 − CH 2 | C H 3 − Ο − C H − Ο − CH 2 −Ο− CH 2 −Ο− CH 2 −Ο− CH 3 1 2 3 4 5 6 7 8 9 10 11 (i) Cl 2 CH CH 2 O ( CH 2 ) 2 O ( CH 2 ) 2 Cl Ethane, 1-(2-chloroethoxy)-2(2,2-dichloroethoxy)- 2,4,6,8,10-Pentaoxaundecane, 3propyl(e) HCO ( CH 2 ) 8 CHO (i) NH2 Benzenenonanal, 4-formyl- (not Benzaldehyde, 4-(9-oxononyl)-) (e) CH = CH − CH 2 − OH | H O − C H 2 − C H 2 − CH 2 − CH 2 − CH − CH = CH − CH 2 − C Η 2 − OH 9 8 7 6 5 4 3 2 1 H2 N N NH NH NH2 3-Nonene-1,9-diol, 5-(3-hydroxy-1propen-1-yl)- (not 2,5-Octadiene1,8-diol, 5-(4-hydroxybutyl)-) 1,4-Benzenediamine, N1,N1-bis(4aminophenyl)-N4-[4-[(4-aminophenyl)amino]phenyl]- ¶ 138 (i,j) Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 (k) H O2 C 1 18 Cl O Cl CO 2 H CH3 CH 2 CH − CH2 | CH 3 CH3 CH 2 CH3 CH3 6 Benzoic acid, 3-(4-carboxy-2chlorophenoxy)-2-chloro(l) CH 2 − O − CH − O − CH 2 Benzene, 2-methyl-1-[1-methyl-2[4-[(3,4,5-trimethylphenyl)methyl]phenyl]ethyl]-4-(phenylmethyl)- (of the two central occurrences of the preferred heading parent, the one with the maximum number (three) of substituents is chosen; note that the centrality principle prevents choice of the tetrasubstituted parent on the right) Benzene, 1,1′-[(phenylmethylene)bis(oxymethylene)]bis(note that all occurrences of benzene are terminal and that the principle of centrality is therefore not applicable) (l,m) (i,l) Cl CH 2 CH2 CH2 Cl Benzene, 1,1′-methylenebis[4[(4-chlorophenyl)methyl]- C−O−C−S−C (i,l) CH 2 Benzene, 1,1′,1′′-[[[diphenyl(triphenylmethoxy)methyl] thio]methylidyne]tris- (not Benzene, 1,1′,1′′-[[diphenyl[(triphenylmethyl)thio]methoxy]methylidynetris-) CH 2 CH CH2 (m) F 3 CCF( CCl 3 ) CO 2 H 32 1 Benzene, 1,1′,1′′-methylidynetris[4-( phenylmethyl)- (when multiplication of the heading parent is permitted, occurrences directly attached to the central connecting radical are included in the same operation if possible) Propanoic acid, 2,3,3,3-tetrafluoro- 2-(trichloromethyl)- (not Propanoic acid, 3,3,3-trichloro2-fluoro-2-(trifluoromethyl)-) (m) O O CHCH 2 (j) H2 N CH − CH 2 − COOH Cyclohexanone, 2-[2-(2-oxocyclohexyl)ethylidene]- (not Cyclohexanone, 2-[2-(2-oxocyclohexylidene)ethyl]-) Benzenepropanoic acid, 4-aminoβ-phenyl- 139. Subtractive nomenclature employs the suffixes “-ene” and “-yne” to signify removal of hydrogen pairs from saturated molecular skeletons; removal of hydrogen atoms from an aromatic system is denoted by “dehydro.” Examples: 1 (j) 6 CH 3 | C C l 3− C− C O OH |2 1 3 CCl 3 Propanoic acid, 3,3,3-trichloro2-methyl-2-(trichloromethyl)(not Propanoic acid, 2,2bis(trichloromethyl)-) (like treatment of like groups is discontinued ( ¶ 255)) 7 4 1 6 Bicyclo[2.2.1]hepta-2,5-diene N Pyridine, 2,3-didehydro- (not Pyridyne) (k) 6 1 NH N Me Me Benzenamine, 2-methyl-N-(4methylphenyl)- Functional class names such as “anhydride,” “ester,” “oxime,” imply loss of water and may strictly be regarded as subtractive terms. Prefixes such as “deoxy,” “nor,” and “anhydro,” are sometimes employed in names for classes of stereoparents (see Section E), but never in general index nomenclature. 19 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 B. MOLECULAR SKELETONS ¶ 143 Introduction Acyclic hydrocarbons Organic hetero chains Homogeneous hetero chains Heterogeneous hetero chains Monocyclic hydrocarbons Monocyclic hetero systems Polycyclic systems Fundamental fused carbocycles Fundamental fused heterocycles Selection of a base component Index names for fused systems Orientation and numbering of fused systems ¶ 140 141 142 143 144 145 146 147 148 149 150 151 152 Replacement (“a”) nomenclature for fused systems Bridged fused systems Von Baeyer nomenclature Spiro systems Ring assemblies Hetero atoms with abnormal valencies Boron molecular skeletons “Hetero” polyboranes Substituent prefixes from molecular skeletons Compound and complex radicals Molecular skeletons as index heading parents Fullerenes ¶ 153 154 155 156 157 158 159 160 161 162 163 163A 140. Introduction. A molecular skeleton is defined for purposes of name selection as a chain or ring of atoms in which the number of hydrogen atoms attached to each skeletal atom is (usually) implied or (occasionally) explicitly stated by citation of the substitutive valency and bonding of the skeletal atoms. Monoatomic hydrides of Group IVA and VA elements (except nitrogen) are also treated as molecular skeletons; so are boron hydrides, but because of their unusual nature these are discussed separately (¶ 159). Examples: CH4 A sH 5 H 3 S iO SiH 2 O SiH 2 H 3 S nS nH 3 set of multiple bonds; when there is a choice, double bonds are preferred over triple bonds. When principal groups (functional suffixes) are present, these and not the multiple bonds are preferred for low numbering. Examples: M e CH =CH CH 2 CH =CH 2 1,4-Hexadiene (not 2,5-Hexadiene) 1,2-Propadiene 3-Hexyne 1,3-Butadiyne 1-Penten-4-yne 6-Octen-1-yne (not 2-Octen-7-yne) 2-Propen-1-ol (not 1-Propen-3-ol) H 2 C=C=CH 2 Methane Arsorane Trisiloxane Distannane 10 9 8 7 6 5 4 3 2 1 M e CH 2 C ≡ CCH 2 M e 6 1 H C ≡ CC ≡ CH 1 4 14 C H 3- C H 2- O- C H 2- CH 2 - O -CH 2- CH 2 - O - CH 2 - CH 2- O - CH 2- CH 3 13 12 11 H C ≡ CCH 2CH =CH 2 5 1 3,6,9,12 -Tetraoxatetradecane M e CH =CH ( CH 2 ) 3 C ≡ CH 1 Benzene H N H 2 C=CH CH 2 O H Pyrrolidine 8 9 9a 1 9H-Fluorene 142. Organic hetero chains containing at least four hetero units (¶ 127) are given “a” names, i.e., replacement names based on the hydrocarbon skeleton by use of “oxa,” “thia,” etc., prefixes. Lowest locants (¶ 137) are assigned to all hetero atoms regardless of type and then to preferred hetero atoms (Table I, ¶ 128). Locants for functional suffixes take precedence for low numbering. Examples: 13 4b 4a CH 3 - CH 2 - O - CH 2 - CH 2 - O - CH 2 - CH 2 - O - CH 2 - CH 2 - O - CH 3 12 11 10 9 8 7 6 5 4 3 2 1 2,5,8,11-Tetraoxatridecane Bicyclo[2.2.1]hept-2-ene 1 CH 3 −− O −− SiH 2 −− CH 2 −− CH 2 −− SiH 2 −− S −− CH 3 2 3 4 5 6 7 8 7′ a 1 1′ 5 Spiro[cyclopentane-1,1′ -[1H ]indene] 2-Oxa-7-thia-3,6-disilaoctane (not 7-Oxa-2-thia-3,6-disilaoctane) CH 3 - CH 2 - SiH 2 - CH 2 - CH 2 - SiH 2 - CH 2 - CH 2 - SiH 2 - CH 2 - CH 2 - SiH 2 - C H 2 -C H 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 4′ 6 3′ 3,6,9,12-Tetrasilatetradecane 7λ4-[1,2]Dithiolo[1,5-b][1,2]dithiole 3 1 7 S 4 S S H 2 C=CH CH 2 [ O ( CH 2 ) 2 ] 3 O M e 14 12 21 2,5,8,11-Tetraoxatetradec-13-ene 3,6,9,12-Tetraoxatetradeca1,4,7,10,13-pentaene H 2 C=CH ( O CH =CH ) 3 O CH =CH 2 14 13 3 1 Molecular skeletons are nonfunctional substitutive parent compounds. Substituents denoting a preferred compound class are generally cited as suffixes and other substituents as prefixes. Molecular skeletons, alone or in combination with a substituent suffix, are index heading parents. This part of the manual deals with the formation of index names for structures that consist solely of one or more molecular skeletons. 141. Acyclic hydrocarbons. Saturated unbranched alkanes containing one through four carbon atoms are named Methane, Ethane, Propane, and Butane. Higher members of the class are named by adding the termination “-ane” to the appropriate multiplicative term, as, Nonane for C9H20, Hexadecane for C16H34, Eicosane for C20H42, Heneicosane for C21H44, and Tritriacontane for C33H68. Unsaturated unbranched acyclic hydrocarbons (unbranched alkenes, alkadienes, alkynes, etc.) are named by replacing the ending “-ane” by “-ene” (for a single double bond), “-adiene” for two double bonds, “-yne” for a single triple bond, etc. Combinations, e.g., “-enyne,” “-trienediyne,” are employed when both bond types are present. Low numbering (¶ 137) is employed for the 143. Homogeneous hetero chains are considered to include the mononuclear hydrides Phosphine (PH3), Phosphorane (PH5), Arsine (AsH3), Arsorane (AsH5), Stibine (SbH3), Bismuthine (BiH3), Silane (SiH4), Germane (GeH4), Stannane (SnH4), and Plumbane (PbH4). Chains composed of two or more of these hydride residues are named by prefixing the hydride name with “Di,” “Tri,” etc. Examples: H 2 BiBiH 2 H 4 PPH 4 H 3 Sn Sn H 2 Sn H 3 H 3 Si( SiH 2 ) 3 SiH 3 Dibismuthine Diphosphorane Tristannane Pentasilane ¶ 143 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 20 Saturated nitrogen chains are named Hydrazine (not Diazane) for H2NNH2, Triazane for H2NNHNH2, Tetrazane for H2NNHNHNH2, etc. Unsaturation is denoted by use of the subtractive suffixes “-ene” and “-yne.” Locants are employed as for hydrocarbon chains (¶¶ 114, 141). Examples: H A s=A sH H 2 S i=SiH 2 H 2 N N =N N H 2 H N =N N =N H 1,3-Cyclopentadiene Diarsene Disilene 2-Tetrazene 1,3-Tetrazadiene Cyclohexene 1,3 -Cyclohexadien -5 -yne (not Benzyne) 144. Heterogeneous hetero chains in which any one of the Group IVA elements (silicon, germanium, tin, or lead) alternates with chalcogen are given “oxane,” “thiane,” etc. names. Examples: H 3 SiOSiH 2 OSiH 3 1 23 45 Trisiloxane Digermaselenane Tristannathiane H3GeSeGeH3 1 23 146. Monocyclic hetero systems. (a) Rings of three through ten members containing nonmetallic hetero atoms (except silicon) are named systematically by the (extended) HantzschWidman system or at trivial names. Table II supplies the stems for the systematic names, which are completed by adding replacement prefixes for the hetero atoms in the order set out in Table I, ¶128, e.g., oxa, thia, aza, together with locants and multiplicative prefixes denoting the position and number of each. A locant for a single hetero atom is not cited. The preferred hetero atom is numbered “1.” This means the set of locants may not be the lowest possible, as defined in ¶137. The letter “a” of replacement prefixes is elided before another vowel in Hantzsch-Widman names; e.g., Dioxazole, not Dioxaazole. Examples: 1 H 3 SnSSnH 2 SSnH 3 1 23 45 O Oxirene Chains of alternating atoms of a Group IVA element and nitrogen, e.g., SiH3NHSiH3, SnH3NHSnH3, are not named Disilazane, Distannazane, etc. Instead, the amine function is recognized; thus, Disilazane is indexed at Silanamine, N-silyl -. However, substituent radicals derived from such heterogeneous chains containing nitrogen, e.g., 1-disilazanyl for SiH3NHSiH2 -, are employed in the presence of higher functions (see ¶161). “A” names for hetero chains are avoided unless carbon substituents can be included in the chain. Otherwise the preferred parent is a homogeneous hetero chain, hydride, or element name. Examples: H 3 G eO SiH 2 S P bH 3 H 3 G eO PbH 2 SeMe 1 23 4 3 H N 1 3 1 Aziridine 6 P Phosphorin Silane, (germyloxy)(plumbylthio)1 2-Oxa-4-selena-1-germa-3plumbapentane O 5 N 3 Oxazole (not 1,3-Oxazole, because the 1,2 - isomer has the trivial name Isoxazole) 145. Monocyclic hydrocarbons (cycloalkanes, cycloalkenes, etc.) are named by attaching the prefix “cyclo” to the name of the acyclic hydrocarbon with the same number of carbon atoms. Unsaturation is expressed by use of “-ene” and “-yne” in place of “-ane” as for the acyclic analogs. No locant is employed for a single multiple bond; lowest locants (¶ 137) are cited when two or more multiple bonds are present. The trivial name Benzene is used for 1,3,5Cyclohexatriene. Examples: Cyclohexane O 5 1 S2 1,2 -Oxathiolane ( all locants are placed ahead of the name; cf. ¶146(c), below) 2H-1,5,2-Dithiazine (not 1H-2,4,1Dithiazine; not 6H-1,3,6-Dithiazine; not 4 H -1,5,4-Dithiazine) (The numbering must begin with a sulfur atom and proceed in the direction that gives lowest numbers to the remaining hetero atoms .) (The “2 H ” signifies indicated hydrogen (see ¶ 135)). 1 S 6 5S 2 NH TABLE II HANTZSCH-WIDMAN STEMS FOR MONOCYCLIC HETERO SYSTEMS OF THREE THROUGH TEN MEMBERS1 No. of members in the ring 3 4 5 6 7 8 9 10 Rings containing nitrogen Unsaturated -irine -ete -ole -ine3 -epine -ocine -onine -ecine 2 Rings containing no nitrogen Unsaturated2 -irene -ete -ole -in3 -epin -ocin -onin -ecin Saturated -irane -etane -olane -ane5,6 -epane -ocane -onane -ecane Saturated -iridine -etidine -olidine 4 4 4 4 4 1The symbols denoting the ring sizes for 3, 4, 7, 8, 9, 10 members are derived from numerical prefixes as follows: “ri” from tri; “et” from tetra; “ep” from hepta; “oc” from octa; “on” from nona; and “ec” from deca. 2Corresponds to the maximum number of noncumulative double bonds when the hetero atoms have the substituent valencies given in Table I, ¶ 128. 3When the Hantzsch-Widman prefixes “phospha,” “arsa,” or “stiba” are immediately followed by the Hantzsch-Widman stems “-in” or “-ine,” they are replaced by the prefixes “phosphor,” “arsen,” or “stibin,” respectively. 4Saturation is expressed by detachable prefixes such as “tetrahydro-,” “hexahydro-,” etc. The prefix “perhydro-” is not used. 5This stem is not used for saturated hetero systems based on the elements silicon, germanium, tin, or lead. Saturation of these rings is indicated by detachable prefixes such as “tetrahydro-,” “-hexahydro-,” etc., when HantzschWidman names are used. 6Saturation of six-membered hetero systems based on the elements boron or phosphorus is denoted by the stem “-inane.” 21 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 148 Table II indicates those cases in which special endings are employed for fully saturated monocyclic hetero systems: e.g., Azetidine, not Azete, tetrahydro-. Special names for partially saturated ring systems are discontinued. Example: 4 1 (c) Rings of more than ten members not containing silicon atoms are indexed at organic replacement (“a”) names. Unsaturation is indicated by “-ene” and “-yne” suffixes. Examples: 11 NH H N 1 Azete, 1,2-dihydro- (not 2-Azetine) 6 Azacycloundecane Certain five- and six-membered monocyclic hetero systems, both saturated and unsaturated, are indexed at trivial names. These names are set out in Table III in the order of the corresponding Hantzsch-Widman names, which are not used for indexing. Fully hydrogenated five-membered rings are given “-olidine” names, as for systematically named systems. Special names for partially hydrogenated five-membered rings e.g., 2-Pyrroline, were discontinued in 1972; they are now named as dihydro derivatives of the fully unsaturated rings. Indicated hydrogen (see ¶135) is necessary in some rings to describe the location of the saturated skeletal atom, e.g., 1H-Pyrrole, 2H-Pyrrole, 3H-Pyrrole. Presence of a triple bond in addition to the maximum number of noncumulative double bonds is expressed by the subtractive prefix “didehydro.” Example: N H P HN 9 HP 8 7 10 11 H N H P 12 5 H N 1 4 2P H 3 6 N H P H O N H NH 1,3,5,7,9,11-Hexaaza-2,4,6,8,10,12hexaphosphacyclododecane P H 1,6-Dioxacyclododec-3-yne O Pyridine, 2,3- didehydro- (d) Rings containing silicon in general are indexed at replacement (“a”) names based on the cyclic hydrocarbons. Systems comprising only silicon atoms or silicon atoms alternating with nitrogen or one of the chalcogens are given “Cyclosila-” names. Examples: H2 Si 1 Silacyclopropane TABLE III MONOCYCLIC HETERO SYSTEMS WITH TRIVIAL NAMES Index name Azine Pyridine Azine, hexahydroPiperidine Azole Pyrrole (1H-, 2H-, or 3H-) Azolidine Pyrrolidine 1,2-Diazine Pyridazine 1,3-Diazine Pyrimidine 1,4-Diazine Pyrazine 1,4-Diazine, hexahydroPiperazine 1,2-Diazole Pyrazole (1H-, 3H-, or 4H-) 1,3-Diazole Imidazole (1H-, 2H-, or 4H-) 1,2-Diazolidine Pyrazolidine 1,3-Diazolidine Imidazolidine 2H-1,4-Oxazine, tetrahydroMorpholine 1,2-Oxazole Isoxazole Oxin Pyran (2H- or 4H-) Oxole Furan 1,2-Selenazole Isoselenazole Selenole Selenophene Tellurole Tellurophene 2H-1,4-Thiazine, tetrahydroThiomorpholine 1,2-Thiazole Isothiazole Thiole Thiophene 1,3,5,2,4,6-Triazatriborine, hexahydro- Borazine 1,3,5,2,4,6-Trioxatriborinane Boroxin 1,3,5,2,4,6-Trithiatriborinane Borthiin Hantzsch-Widman name 3 H N1 5 N2 3 1,2,4-Triaza-3-silacyclopent-2-ene HN 4 Si H H Si 6 1 Silabenzene 5 H2 Si 1 H 2 Si H2 Si 4 2 Si H2 Si H2 3 Cyclopentasilane H2 Si 4 H N 1 3 2 SiH2 Cyclodisilazane N H H2 Si 10 O 11 O9 H 2 Si 8 7 6 H2 O Si 12 1 2 Si H 2 O3 Cyclohexasiloxane O 5 4 O Si H2 Si H2 (b) Rings of three through ten members containing antimony, tin, lead, germanium or bismuth atoms in addition to carbon atoms are indexed at Hantzsch-Widman names. Partially saturated and fully saturated six-membered ring systems of this type containing germanium, lead or tin are named on the basis of the unsaturated rings. Heterocycles containing metallic atoms other than the above five are indexed by coordination nomenclature (¶ 215). Examples: 1 O 6 2 Sn H 2 O3 4H-1,3,2-Dioxastannin, dihydro- 1 H2 Ge H 2 Ge 4 5 O 2 147. Polycyclic systems may be subdivided into four classes as follows: (a) Fused systems contain at least two rings of five or more members and only “ortho-” or “ortho- and peri-” fusions (see below). (b) Bridged systems are monocyclic or fused systems with valence bonds, atoms, or chains connecting different parts of the structure. (c) Spiro systems have pairs of rings (or ring systems) with only one common atom. (d) Ring assemblies have pairs of rings (or ring systems) connected by single bonds. In the following sections, methods of naming ring systems of all these types will be described. The names of more complicated cases are built up from base components which may be described as “fundamental” systems. 148. Fundamental fused carbocycles with ortho-fusions only, e.g., Naphthalene, have adjoining rings with only two atoms in common; they thus have n common faces and 2n common atoms. An ortho- and peri-fused system contains a ring which has two, and only two, atoms in common with each of two or more rings, the total system containing n common faces and fewer than 2n common atoms. Examples: 4 1 12 c 12 a 12 b 7 5 6 8 9 10 a 1 Ge H 2 Ge H 2 3 Oxatetragermolane 3 10 c 10 b 4 6 5 1 6 S 4 2 H 2Sn 5S Sn H 2 Sn H2 S3 1,3,5,2,4,6-Trithiatristannin 9 8 An ortho-fused system An ortho- and peri-fused system (3 common faces; 6 common atoms) (5 common faces; 6 common atoms) ¶ 148 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Rubicene Coronene Trinaphthylene Heptaphene Heptacene Pyranthrene Ovalene 22 Systems of five or more ortho-fused benzene rings are named by the “acene” system if the arrangement is linear, by the “phene” system if one central angular site is present. Examples: 11 12 13 14 14a 1 Pentacene 8 7 6 5 4 C5-C5-C6-C6-C6-C6-C6 C6-C6-C6-C6-C6-C6-C6 C6-C6-C6-C6-C6-C6-C6 C6-C6-C6-C6-C6-C6-C6 C6-C6-C6-C6-C6-C6-C6 C6-C6-C6-C6-C6-C6-C6-C6 C6-C6-C6-C6-C6-C6-C6-C6-C6-C6 1 20a 20 5 15 16 17 19 18 18 a 18b 7 12 11 10 9 8 6 4 149. Fundamental fused heterocycles often have trivial names, e.g., Cinnoline, Xanthene. Others belong to one or another semisystematic system. A linear set of three fused six-membered rings with the same hetero element in both unfused positions of the central ring are given “-anthrene” names. Example: Octaphene 9 10 B 10a 1 Boranthrene 6 B 5 4 Names ending in “-alene” are employed for bicyclic fused systems, and in “-phenylene” for systems built up from benzene rings fused to alternate sides of a monocyclic hydrocarbon. (Analogous “-naphthylene” names have been used for corresponding 2,3-fusion systems of naphthalene.) Examples: 1 6a A similar set with different hetero elements in these positions is given a “Pheno-” name containing the organic replacement terms in the usual order (Table I, ¶128) and the ending “-in” (or “-ine” if nitrogen, phosphorus or arsenic is included). Example: 9 Pentalene 4 3 1 12a 12b 8b 8a 4a 4b H Si 10 10a 1 1H-Phenoxasilin 4 Triphenylene 8 O 5 Table IV lists the names of trivially-named fundamental fused carbocycles in ascending order of preference for adoption as base components in the naming of more complex fused hydrocarbon systems. Also included are some of the names discussed immediately above. (The order is based on the rules described in ¶¶138, 150.) The ring analyses describe the number of component rings and the number of atoms each ring contains. Diagrams of these rings, which show the preferred orientation and numbering, are displayed in the Ring Systems Handbook. Diagrams justified by current entries are also provided in the semiannual and collective Chemical Substance Indexes. The following ring systems require citation of indicated hydrogen (¶ 135) to complete the name: Indene, Fluorene, Phenalene, Trindene. TABLE IV FUNDAMENTAL FUSED CARBOCYCLES IN ASCENDING ORDER OF PRECEDENCE FOR USE AS BASE COMPONENTS IN FUSED SYSTEMS Name Pentalene Indene Naphthalene Azulene Heptalene Biphenylene as-Indacene s-Indacene Acenaphthylene Fluorene Phenalene Phenanthrene Anthracene Trindene Fluoranthene Acephenanthrylene Aceanthrylene Triphenylene Pyrene Chrysene Naphthacene Pleiadene Picene Perylene Pentaphene Pentacene Tetraphenylene Hexaphene Hexacene Ring analysis C5-C5 C5-C6 C6-C6 C5-C7 C7-C7 C4-C6-C6 C5-C5-C6 C5-C5-C6 C5-C6-C6 C5-C6-C6 C6-C6-C6 C6-C6-C6 C6-C6-C6 C5-C5-C5-C6 C5-C6-C6-C6 C5-C6-C6-C6 C5-C6-C6-C6 C6-C6-C6-C6 C6-C6-C6-C6 C6-C6-C6-C6 C6-C6-C6-C6 C6-C6-C6-C7 C6-C6-C6-C6-C6 C6-C6-C6-C6-C6 C6-C6-C6-C6-C6 C6-C6-C6-C6-C6 C6-C6-C6-C6-C8 C6-C6-C6-C6-C6-C6 C6-C6-C6-C6-C6-C6 An exception is Phenazine for the analog that contains nitrogen in both central positions. Arsenic and phosphorus analogs of fused nitrogen heterocycles (Indole, Quinoline, etc.) are named as follows: Arsindole, Isoarsindole, Arsinoline, Isoarsinoline, Phosphindole, Isophosphindole, Phosphinoline, Isophosphinoline, Arsanthridine, Acridarsine, Acridophosphine, Phenarsazine, Phenophosphazine. The replacement of the oxygen in Xanthene by sulfur or selenium has been denoted by the appropriate chalcogen functional replacement prefix: Thioxanthene, Selenoxanthene. In the “benzo” system, bicyclic fused heterocyclic systems containing a benzene ring and a ring named by the Hantzsch-Widman system are indexed by prefixing the latter name by “Benz-” or “Benzo-.” Indicated hydrogen, if necessary, and locants are placed in front of the complete name. Similar names are used when benzene is fused to a monocycle with a trivial name (unless the bicyclic system itself has a trivial name). Examples: 8a N O3 1 4H-3,1-Benzoxazine (not 4H-Benz[d]oxazine) 5 4 1 7a O N3 Benzoxazole (locants are not cited; the isomers are named 1,2- and 2,1Benzisoxazole) 4 1 7a O 3 Benzofuran (the isomer is named Isobenzofuran) 4 Such “benzo” names are not usually adopted as base components of fused systems when only hydrocarbon rings are fused to the benzene portion. When benzene is fused to a heterocyclic ring containing more than ten skeletal atoms, “Benzo-” or “Benz-” is placed ahead of the replacement (“a”) name of the saturated ring and the ending changed to “-in” (or “-ine” if nitrogenous) to indicate the maximum number of noncumulative double bonds. (Saturated positions other than those occupied by indicated hydrogen are denoted by hydro substituents.) Example: 1 15a O 6 2H-1,11-Benzodioxacyclotridecin, 5,6-dihydro- 12 11 O 23 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Triphenodioxazine Phenanthrazine Anthrazine C4NO-C4NO-C6-C6-C6 C4N2-C6-C6-C6-C6-C6-C6 C4N2-C6-C6-C6-C6-C6-C6 ¶ 151 Trivially named fundamental fused hetero systems are listed in Table V. Also included are some of the systems discussed immediately above, as well as a selection of monocyclic hetero systems to help illustrate the ascending order of priority for adoption as base components in complex fused systems. Fused systems containing only silicon and carbon skeletal atoms are indexed at “Sila-” replacement names if the corresponding hydrocarbon has a fundamental name (Table IV, ¶148). TABLE V FUNDAMENTAL HETEROCYCLES IN ASCENDING ORDER OF PRECEDENCE FOR USE AS BASE COMPONENTS IN FUSED SYSTEMS1 Index Name Isoarsindole2 Arsindole2 Isoarsinoline Arsinoline Arsanthridine Acridarsine Arsanthrene Isophosphindole2 Phosphindole2 Isophosphinoline Phosphinoline Tellurophene Selenophene Selenanthrene Thiophene Thianthrene Furan Pyran2 Isobenzofuran Xanthene2 Phenoxastibinin Phenoxarsine2 Phenoxaphosphine2 Phenoxatellurin Phenoxaselenin Phenoxathiin Pyrrole2 Imidazole2 Pyrazole2 Isothiazole Isoxazole Pyridine Pyrazine Pyridazine Pyrrolizine2 Indolizine Isoindole2 Indole2 Indazole2 Purine2 Isoquinoline3 Quinoline3 Quinolizine3 Phthalazine Naphthyridine4 Quinoxaline Quinazoline Cinnoline Pteridine Carbazole2 Phenanthridine Acridine Perimidine2 Phenanthroline5 Phenazine Anthyridine Phenarsazine Phenophosphazine Phenotellurazine2 Phenoselenazine2 Phenothiazine2 Phenoxazine2 Thebenidine Quindoline2 Quinindoline2 Phthaloperine2 Acrindoline2 Triphenodithiazine Ring Analysis C4As-C6 C4As-C6 C5As-C6 C5As-C6 C5As-C6-C6 C5As-C6-C6 C4As2-C6-C6 C4P-C6 C4P-C6 C5P-C6 C5P-C6 C4Te C5Se C4Se2-C6-C6 C4S C4S2-C6-C6 C4O C5O C4O-C6 C5O-C6-C6 C4OSb-C6-C6 C4AsO-C6-C6 C4OP-C6-C6 C4OTe-C6-C6 C4OSe-C6-C6 C4OS-C6-C6 C4N C2N2 C3N2 C3NS C3NO C5N C4N2 C4N2 C4N-C4N C4N-C5N C4N-C6 C4N-C6 C3N2-C6 C3N2-C4N2 C5N-C6 C5N-C6 C5N-C5N C4N2-C6 C5N-C5N C4N2-C6 C4N2-C6 C4N2-C6 C4N2-C4N2 C4N-C6-C6 C5N-C6-C6 C5N-C6-C6 C4N2-C6-C6 C5N-C5N-C6 C4N2-C6-C6 C5N-C5N-C5N C4AsN-C6-C6 C4NP-C6-C6 C4NTe-C6-C6 C4NSe-C6-C6 C4NS-C6-C6 C4NO-C6-C6 C5N-C6-C6-C6 C4N-C5N-C6-C6 C4N-C5N-C6-C6 C5-C4N2-C6-C6-C6 C4N-C5N-C6-C6-C6 C4NS-C4NS-C6-C6-C6 1The order of precedence is based first on the presence or absence of nitrogen, then upon the nature of the (other) hetero atoms (see Table I, ¶ 128). For fused heterocycles, this order (for base-component selection) is distinct from that used to determine seniority of a total ring system in an index name (¶ 138). 2Citation of indicated hydrogen (¶ 135), e.g., 1H-Pyrrole, 2H-Pyrrole, is necessary when these component names are used alone. 3Because of established usage, Quinolizine is favored over Isoquinoline and Quinoline as a base component. 4Naphthyridine requires the locants 1,5-, 1,6-, 1,7-, 1,8-, 2,6- or 2,7- to define the position of the nitrogen atoms. 5Phenanthroline requires the locants 1,7-, 1,8-, 1,9-, 1,10-, 2,7-, 2,8- or 2,9- to define the positions of the nitrogen atoms. 150. Selection of a base component is facilitated by use of Tables IV, ¶ 148 and V, ¶149; the appropriate component listed latest in these Tables is used. The system must contain at least two rings of five or more atoms, although such rings need not be directly fused to one another; i.e., they may be joined by a smaller ring, as in Cyclobutadicyclopentene. The criteria for base components differ markedly (in the case of heterocyclic systems) from those described (¶ 138) for a preferred ring system in a compound containing more than one. A base component of lower preference is used if the fusion procedure is not possible on the preferred component; as a last resource, an organic replacement (“a”) name based on the fused hydrocarbon is employed. The preferred base component should: (a) be a heterocycle; (b) be a nitrogenous heterocycle; (c) be a nonnitrogenous heterocycle containing a hetero atom of highest precedence (see Table I, ¶ 128); (d) contain the greatest number of rings; (e) contain the largest individual ring; Benzindene (not Cyclopentanaphthalene) is an exception based on established usage; (f) contain the greatest total number of hetero atoms; (g) contain the greatest variety of hetero atoms, e.g., one nitrogen and one oxygen rather than two nitrogens; (h) contain the greatest number of hetero atoms of highest precedence; (i) possess the most linear structure; (j) have the lowest locants for hetero atoms (before fusion). 151. Index names for fused systems, other than fundamental systems which possess their own names (Tables IV, ¶ 148 and V, ¶149), are formulated from the names of the components. Cycloalkanes may be adopted as base components by invariant use of the “-ene” suffix. This denotes a maximum number of noncumulative double bonds; e.g., Cyclooctene as part of a fused system is not meant to imply the presence of a single double bond; instead, saturated carbon atoms are indicated by “hydro” prefixes. Fusion locants for the base component comprise lower case italic letters assigned sequentially to all sides, beginning with the side “1,2” as denoted by the usual peripheral locants. (See the Ring Systems Handbook for a complete set of ring system diagrams, including base components, complete with such locants.) If more than twenty-six letters are required, subsequent alphabets of the form a1, b1, c1,... etc., are adopted. Locants for the fusion prefixes (derived from the less preferred fundamental ring systems) comprise the normal peripheral numerical locants. When a choice is possible, lowest alphabetic and numerical locants are cited. When one or both types of locants are unnecessary they are usually omitted. Numerical and letter locants are separated by a hyphen, and the locant set is bracketed. Example: Benzene + j i h g f e d c k l m n 1 11 a 2 b 8 7 12 12a 1 4 12b 5 6 Anthracene (base component) Benz[a]anthracene In this example, a locant defining the fusion site on Benzene is unnecessary. The “1,2” side of Anthracene is lettered “a” and the lettering proceeds around every side back to the 1-position. The fused system is then oriented (¶ 152) and renumbered. ¶ 151 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 24 Angular positions of base components involved in fusion are not cited. Example: Naphthalene 5′ 8 a b c d e f 4′ 8a 1 2 3′ 4′ 2′ 1 1′ 3 f 2 a 4 1′ 2 2′ 3 f 1 a + NOT Cyclopenta[ a ]cyclopropa[4 ′ ,5 ′ ] cyclopenta[1′,2′:2,3]cyclopropa[ 1 , 2 -f ] n a p h t h a l e n e ( n o t Cyclopenta[ a ]cyclopropa[3 ′ ,4 ′ ]cyclopenta[2 ′ ,1 ′ :1,3]cyclopropa[2,1-f ]naphthalene.) (The locants 1,2 in the preferred name are lower than 2,1 in the incorrect name. It should be noted that the use of 1′ ,2′ requires that the cyclopentane ring be numbered the long way around.) Perylene Naphtho[8,1,2-bcd]perylene (not “[8,8a,1,2-bcd]”) 2′ a′ 1′ 3′ 3 5′′ 1′′ 4′′ 2′′ 4 4′ 2 a 1 When a hetero atom is shared by two or more rings, it is expressed in all the components. When the order of lettering of the base component proceeds in the direction opposite to numbering in the fusion-prefix component, numerical locants for the latter are reversed. Example: 3 b 54 1′′ 2′ 2′′ 4 ′ 3 ′′ 5′ 6′ 1′ O Benzo[1 ′′ ,2 ′′ :3,4;5 ′′ ,4 ′′ :3 ′ ,4 ′ ]dicy clobuta[1,2 -a :1 ′ ,2 ′ -a ]diindene (Note that a semicolon separates locant sets which already contain colons.) O1 2 N 6 2 N a 1b I s o i n d o l o [ 2 , 1 -a ] q u i n o x a l i n e (not “[2,3-a]”; not “[1,2-c]”) N 3′ N Pyrrolo[2′′,3′′:4′,5′]pyrano[2′ ,3′ :5,6]pyrano[4,3-b]pyrrole Fusion prefixes are placed in alphabetical order and the earliest cited prefix is given preference for lowest letter locant. When two or more fusion prefixes are identical, as in “Dibenzo-” systems, the letter locants are separated by commas, e.g., “[a,j].” Example: j a Benzo[ a ]cyclopent[ j ]anthracene A form of multiplicative name is employed for fused systems different from that described for general substitutive nomenclature. Multiplication proceeds in steps, with “di,” “tri” repeated as necessary (not “bis,” “tris,” etc., except to avoid ambiguity). Serially primed letters are used for fusion sites on the second, third, etc., base components and the locant sets are separated by colons. When a base component is fused to a central component and to another component, lowest letters (when a choice must be made) relate to the central fusion site. Examples: 152. Orientation and numbering of fused systems. (a) Hydrocarbons. The component rings are normally drawn as regular polygons. The cyclopropane ring may point left or right, and cyclopentane and cycloheptane rings may point up or down. The total system is oriented so that (a) a maximum number of rings are in a horizontal row, and (b) a maximum number are above and to the right. If further choice is necessary, then (c) a minimum number of rings should be in the lower left quadrant. Numbering begins at an atom not engaged in fusion in the most counterclockwise position of the uppermost ring furthest to the right. Angular positions are not counted; their locants, when needed, are derived from those of the preceding nonangular positions by addition of the lower-case Roman letters, “a,” “b,” etc. Interior atoms are numbered last by addition of letters to the highest available numerical locant in a continuous pathway, a clockwise route being followed whenever a choice presents itself; any remaining interior atoms are then numbered similarly from the next highest available numerical locant. Examples: 10 11 12 12 a 1 Naphthacene 7 6 5 4 9 8 10a 1 9 3 4 10a 5c 1 O c 10c 10b NOT 8 3 4 5b 5a O 6 c ′′ 5 1 4 2 3 c′ Benzo[1,2-c:3,4-c′:5,6-c′′]trifuran 6 5 Pyrene O 4 4 1 16d 16c 7 11 10 9 8 11 10 9 8a 8 5 6 14 5 6 7 1 d′ 2′ 4 b′ 5′ 2 b 1 1 d Dinaphtho[1,2 -d :1 ′ ,2 ′ -d ′ ]benzo [1,2 -b :5,4 -b ′ ]dithiophene (not Dinaphtho[2,1-b :2 ′ ,1 ′ -b′ ]benzo[1,2-d :5,4-d ′ ]dithiophene) 1 16a 16b 13a 13b NOT 13 16b 16a 8d 8c 8b S S 2 Ring systems fused to base components are designated primary components; a ring system (other than a base component) fused only to a primary component is a secondary component, and primed numerical locants are used to denote its fusion sites. Primed and unprimed locant sets are separated by colons. Lowest locants are used for the site closest to (or fused directly to) the base component. Doubly primed locants are needed (a) when the secondary component is centrally located with identical primary and base components on both sides, and (b) when tertiary components are present. Examples: Naphtho[1′ ,8′ :3,4,5]cyclohepta[1,2-c]phenanthrene When a further choice is needed for orientation and numbering, carbon atoms at angular positions are assigned lowest numbers. Examples: 1 8a 2 3 1 3 4 5 6 5 6 NOT 8a 8b N 5 b4 3 1 2 N Pyrido[1 ′ ,2 ′ :1,2]imidazo[4,5 -b ] quinoxaline 8b N N Acenaphthylene (Note: 2a,5a,8a,8b is lower than 3a,5a,8a,8b) 25 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 154 Indicated hydrogen is assigned the lowest locant. Example: 1 7a 1H-Indene (not 3H-Indene) 3 4 153. Replacement (“a”) nomenclature for fused systems is employed when fusion names fail to express all interfaces (fusion sites) between component systems. This occurs when two or more components that are expressed as prefixes are fused to one another as well as to the base component. “A” names are also used for silicon replacement in a carbocycle that has a trivial name. Indicated hydrogen of the parent carbocycle is ignored, but is cited, if needed for the “a” name, ahead of the replacement prefixes. Examples: 1O 7a 7O 7b 2 3 4 5 The following fused carbocyclic compounds have special numbering systems: Anthracene, Phenanthrene, Cyclopenta[a]phenanthrene (steroid numbering) and the Cyclopropacyclopenta[a]phenanthrenes. (b) Heterocycles. The ring systems are oriented as for hydrocarbons. When a choice is necessary, lowest locants are assigned to (a) all hetero atoms; (b) most preferred hetero atom (Table I, ¶ 128); (c) carbon atoms common to two or more rings; (d) positions bearing indicated hydrogen; (e) an angular rather than a nonangular atom of the same hetero element. The ring is then numbered as for hydrocarbons, except that hetero atoms common to two or more rings are counted. Interior atoms are numbered last, following the shortest path from the highest previous number. Examples: 1 7a 5 4 6 H− 1,7 −Dioxacyclopent[ cd]indene (not 1,7-Dioxa-6H-cyclopent[cd]indene) 1 9a 9b 3 B 7 6 4 9b-Boraphenalene O 8a H Si 1 Cyclopenta[b]pyran 5 1-Silanaphthalene, 3,4-dihydro- 4 1 9a N 4,1-Benzothiazepine 6 5 S 4 6 1 6a S 4 O Thieno[2,3-b]furan 3 6 1 6a N HN 4 O 4H-1,3-Dioxolo[4,5-d]imidazole O3 1 8 8 1 8a N NOT N N NOT 8 1 8a N 5N 4a N N Saturation of double bonds in fused systems is denoted by hydro prefixes which are given lowest locants; e.g., Naphthalene, 1,2,3,4(not 5,6,7,8)tetrahydro-. Triple bonds are indicated by “didehydro.” 154. Bridged fused systems are fused ring systems that possess atomic bridges or valence bonds which connect two or more parts of the system without creating or extending a fused system. They are named by adding bridge prefixes (in alphabetical order if different types are present) to the fused system names. Simple bivalent bridges include methano (−CH2−), ethano (−CH2−CH2−), etheno (−CH=CH−), propano (−CH2CH2CH2−), 2-buteno (−CH2CH=CHCH2−), and benzeno (−C6H4−). Trivalent bridges, e.g., metheno (−CH=), 1-propanyl-3-ylidene (−CH2CH2CH=), and tetravalent bridges are also employed; locants for positions of attachment on the fused system are cited in the same order as free-valency locants of the radicals. Bridges from monocyclic hydrocarbons other than benzene are named as for the fusion prefixes, except that “endo-” is used with them to avoid ambiguity, e.g., “endo-cyclopenta.” Simple hetero bridges include epoxy (−O−), epithio (−S−), imino (−NH−), epidioxy (−O−O−), and -silano- (−SiH2−). Heterocyclic rings may also be used as bridges. Example: O N 4 N 5 N 4 N 5 N 4 Imidazo[1,2-b][1,2,4]triazine 3,4-furano (cf. “furo” for the fusion prefix) 11 10a 10b 12 12a 1 NOT 10 11 12 12 a 12b 1 7 N 6 5a N 5 4a 6a N 6 5a N 5 4 Pyrrolo[1,2-a:5,4-b′ ]diindole When locants are used for the bridge itself, e.g., 2-buteno, 3,4-furano-, they are placed in brackets within the bridged system name. Compound bridges are named by combination of simple bridges beginning at the terminal position which gives the preferred (a) cyclic bridge (¶ 138), (b) hetero atom (Table I, ¶ 128), (c) chain, (d) alphabetic order. Examples: NH(CH2)2− (iminoethano) (epoxythioxy) O 1 7O 8a 8b 9 2 N 5a 3 F u r o [ 3 , 4 -a ] p y r r o l o [ 2 , 1 , 5 - c d] indolizine −OSO− 5b (epoxy[1,2]benzeno) The following heterocyclic systems have special numbering systems: Acridine, Carbazole, Purine, Xanthene, and Epoxy- and Epithiocyclopenta[a]phenanthrenes (steroid numbering). Indicated hydrogen for fused carbocyclic and heterocyclic systems is normally cited, if there is a choice, at the lowest nonangular position, unless a saturated angular atom is required to accommodate a principal function or free valency (see ¶ 135). Indicated hydrogen of component systems is ignored in constructing a fused ring name, and is reassigned if it is still needed in the final system. Example: 1 11 12 Indicated hydrogen of a fused system is cited, if possible, to accommodate a bridge. When this is unnecessary or impossible, the lowest-numbered nonangular indicated hydrogen is cited for the fused system, and additional indicated hydrogen, when needed, is cited ahead of the bridge locants. Examples: 1 6a 7 4 3 1,4-Methanopentalene, 1,4-dihydro- O 12a 12b 5 4 8 O 7 O 6 5 H-[2]Benzopyrano[3,4 -b ][1,4] benzodioxin ( Note: The locants “2” and “1,4,” which relate to the components, are bracketed to indicate that they do not confor m to the peripheral numbering of the total system) 1 6a 6 5 7 6b 2 3 8 4 6,1,3-Ethanylylidenecyclopenta[cd] pentalene ¶ 154 21 22 15 18 11 17 16 12 13 14 14 a 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 1 8a 7 9 10 4 26 N NH 2 6,13[2 ′ ,3 ′ ] -Naphthalenopentacene 4 O 5 NOT 8 7 6 5 9 14 12 8 9 11 1 9a 10 1,7 -Ethano -1 H -pyrano[3,2 -c ] pyridazine, octahydro- (not 4,6(Epoxymethano) -1H -pyrido[1,2 b]pyridazine, octahydro-)(The fused ring system Pyranopyridazine is preferred to Pyridopyridazine ; see ¶ 138.) N H N 1 O 11 4 9,10[1′ ,2′ ]-endo-Cyclobutanthracene 5 10 a 5 10 4a 4 1 6a 6 4O 7 8 O 2 3 3,2,6 -(Epoxyethanylylidene)furo [3,2-b]furan Fused carbocyclic and nonnitrogenous heterocyclic systems with simple imino bridges are named by use of the termination “-imine” with appropriate locants. Such a name requires addition of a regular functional suffix when appropriate. (Nitrogen heterocycles with imine bridges are named as bridged fused heterocycles in the usual manner.) Example: 1 8a O 9 Br 9 NCO2 H 1 10a 10 11 12 6 7 10b 3 4 N a p h t h a l e n -4 a , 8 a -i m i n e -9 carboxylic acid, 2,3 -dibromo octahydro - 7 , 1 0 -E t h e n o c y c l o h e p t a [ d e ] naphthalene 4a Br 1 8a 7 10 4a 9 O 5H-4a,7-Ethano-2H-1-benzopyran (4aH-1-Benzopyran cannot exist) Numbering of bridged fused systems is based on the regular numbering of the parent fused system. Lowest locants are assigned to bridgehead positions and the bridge atoms are numbered from the end nearest the highest numbered position of the parent fused system. In cyclic bridges, e.g., benzeno, endocyclobuta, the shorter bridge is first numbered, and then the rest of the ring in the same direction. If possible, hetero atoms in bridges are numbered low. Examples: 10 11 12 12a 14 13 7 6 1 8a 9 NH 10 4a 5 4 1 155. Von Baeyer nomenclature. This was first developed to name alicyclic hydrocarbons containing two rings. It has been extended to all bridged systems which cannot be treated as fused or bridged fused systems. Von Baeyer names for hydrocarbons are formed by prefixing to the name of the acyclic hydrocarbon with the same number of carbon atoms “Bicyclo-,” “Tricyclo-,” etc., terms, followed by a set of numerals, separated by periods and bracketed, which describes in descending sequence the number of atoms in each bridge. The system is numbered from one bridgehead via the other bridgehead(s) and back, always choosing the longest route. The system is numbered along the same route, ending with the smallest bridge, numbered from the bridgehead with the highest locant. Example: 6 11 10 9 1 Bicyclo[4.3.2]undecane 1,4-Ethenonaphthacene For tricyclo- and higher hydrocarbon systems, superscripts are employed to indicate the positions of secondary bridges. Example: 8a,4a-(Iminomethano)naphthalene ( n o t 4 a , 8 a -( I m i n o m e t h a n o )naphthalene) 1 10 11 7 6 2 12 Tricyclo[,6]dodecane 15 12 9 11 1010a 1 O 11 H -5,10[1 ′ ,2 ′ ] -endo -Cyclopent 5H-oxazolo[3,2-b]isoquinoline N 6 5 4 The exceptional numbering employed for bridged cyclopenta[a]phenanthrenes is shown in the following example. Steroid numbering is used for positions 1 through 17. When the methyl groups normally numbered 18 and 19 are transformed into methano bridges, their locants are retained. Other bridges are numbered 20 and upward. 17 19 1 20 O 4 10 11 9 8 13 18 15 When more than one Von Baeyer name is possible for a hydrocarbon, the choice is determined by the following principles, applied successively until a decision is reached. (a) The main ring contains the maximum number of atoms, two of which must serve as bridgeheads for the main bridge. (b) The main bridge is as large as possible. (c) The main ring is divided as symmetrically as possible by the main bridge. (d) Lowest superscripts (regardless of order of citation) are cited. Examples: 1 7 9 4 5 5 7 8 2 16 14 18 17 19 10 5 1 1 2 8 Tricyclo[,4]nonane (not Tri− cyclo[,3]nonane) 6 Tricyclo[ 2,7]octane (not Tricyclo[,6]octane) Criteria for the naming of bridged fused systems are applied successively as follows: (a) The unbridged system contains the maximum number of (i) rings, (ii) skeletal atoms. (b) The bridges are as simple as possible; e.g., two simple bridges are preferred to one compound bridge, and saturated bridges are preferred to unsaturated ones. (c) The unbridged system has the highest precedence according to ¶ 138(c). Examples: 1 8a 9 5 4 Tricyclo[,14]nonadecane 10 1 1,4 -Methanonaphthalene, 1,2,3,4 tetrahydro - (not 1,3-Ethano1H-indene, 2,3-dihydro-) 11 6 5 12 Tricyclo[,5]dodecane (not Tricyclo[,6]dodecane) 27 10 1 8 7 6 2 5 3 4 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Pentacyclo[,5.03,8.04,7]decane (not Pentacyclo[,9.05,8.07,10] d e c a n e ; n o t P e n t a c y c l o[ 2,5 .0 3,10 .0 4,9 ]decane; not Pentacyclo[ 2,9 .0 3,8 .0 7,10 ] decane) ¶ 156 Unsaturation is denoted by “-ene” and “-yne” suffixes. A second locant in parentheses is cited for a double bond at a bridgehead when it does not proceed to the next atom in the numbered path. Multiple-bond locants are determined by the following criteria applied successively: (a) The numbering proceeds in a clockwise sequence. (b) The cases in which both locants for a double bond are cited are minimized. (c) Lowest locants are employed. Examples: 8 9 5 10 2 1 156. Spiro systems contain pairs of rings or ring systems having only one atom (a “spiro atom”) in common. In the simplest monospiro systems, in which two alicyclic rings share an atom, the name is formed by prefixing to the acyclic hydrocarbon name the term “Spiro” and numerals (separated by periods) in ascending sequence to define the number of atoms in each ring linked to the spiro atom. The numbering begins at the atom next to the spiro atom in the smaller ring and proceeds around that ring, through the spiro atom and around the larger ring. Example: 8 4 1 Spiro[3.4]octane This system is extended to dispiro and higher systems. Numbering begins next to a terminal spiro atom and proceeds in such a way as to give the spiro atoms lowest locants. Example: 15 8 16 17 1 6 Tricyclo[,8]deca-3,6-diene Dispiro[]heptadecane ( note that the numbering path corresponds to the bracketed sequence) 8 1 6 1 14 15 11 8 16 Bicyclo[4.2.0]oct -6-ene (not Bicyclo[4.2.0]oct-1(8)-ene) 4 Heterocyclic analogs are named by “a” nomenclature. The hetero atoms are given locants as low as are compatible with the ring numbering. Example: 10 5 1 Tricyclo[ 4,8 ]hexadeca -1 (15),4,6,8(16),11,13-hexaene (not Tricyclo[,8]hexadeca-4,6,8(16),11(15),12,14-hexaene) 6-Oxaspiro[4.5]decane O 6 Von Baeyer names for heterocyclic systems are formed from the hydrocarbon names by use of replacement (oxa, thia, aza, etc.) prefixes and lowest locants for hetero atoms in the order of Table I, ¶ 128. Unsaturation is denoted as for hydrocarbons. Examples: 6 7 2 1 Unsaturation is expressed by “-ene” and “-yne” suffixes. Example: 10 O 6 N 12 4 1 9 5,10-Dioxa-12-azadispiro[]dodec-11-ene O 4 3O 3-Oxatricyclo[,6]heptane (not 5-Oxatricyclo[,6]heptane; not 2-Oxatricyclo[,5]heptane) (low numbering for bridge takes precedence over hetero atom) 6-Oxa-2-thia-4-azabicyclo[3.1.0]hexane ( not 6-Oxa-4-thia-2azabicyclo[3.1.0]hexane) 5 Saturated spiro systems containing only silicon atoms or silicon atoms alternating with nitrogen or one of the chalcogens are given Spirosilazane, Spirosiloxane, etc., names. Example: 11 2 1 6O 5 S NH 4 O H 2 Si 10 9O H2 Si 12 13 1 O O Si 6 H2 Si 2 4 O3 Spiro[5.7]hexasiloxane 8 Si H2 O7 O 5 Si H2 8 1 S2 93 Sb H 5 S 4 2,4 -Dithia -3 -stibabicyclo[3.3.1] nona -1(9),5,7 -triene ( not 2,4Dithia-3-stibabicyclo[3.3.1]nona1(8),5(9),6-triene) Saturated bridged systems containing only silicon atoms, or silicon atoms alternating with nitrogen or one of the chalcogens, are given Bicyclosilazane, Tricyclosiloxane, etc., names. Regular Von Baeyer numbering is employed. Examples: 9 Monospiro systems containing at least one fused or bridged component are named by placing the component names in brackets in alphabetical order and prefacing them with “Spiro.” The position of the spiro atom is denoted by two locants, separated by a comma, related to the two components. Primes are used for the component cited second. Indicated hydrogen (¶ 135) is assigned, where possible, to accommodate the spiro unions. Locants related to the components but not to the total spiro system are bracketed to avoid ambiguity. Example: 5 H 2 Si H2 Si 8 H2 H2 Si H Si 3 10 Si 1 2 Si H2 Si 7 Si H H2 8 6 5 Bicyclo[4.4.0]decasilane 4′ 7′ a 1 1′ Spiro[cyclopentane -1,1 ′ -[1 H ] indene] ( not Spiro[cyclopentane − 1,1′ -1′ H-indene]) 3′ SiH2 4 Si H2 6′ 7′ 8′ 3′ 9 1′ HN H2 Si 7 H Si 1 2 4′ HN 6 NH NH Si H 2 Si 5 NH H4 14 3 Bicyclo[3.3.1]tetrasilazane 8 S 2′ 9a Spiro[9 H − fluorene -9,3 ′ -[2]thia bicyclo[2.2.2]oct[5]ene] 1 4b 4a O 13 H Si 15 17 H Si 12 O OH 11 Si 10 O 9 H Si 16O O 18 O2 4 1 Pentacyclo[ 3,9 .1 5,15 .1 7,13 ] octasiloxane Added hydrogen (¶ 136) is cited in parentheses in the usual way, but with a primed locant if it does not relate to the component cited first. It is assigned the lowest available locant unless a different one can be used to accommodate a principal group. Example: H N1 5 4 2′ 19 O HSi 8O 3 Si OH 20 O Si H 5 8′a H N 1′ NH 3 Spiro[imidazolidine -4,2 ′ (1 ′ H ) quinoxaline] H Si 7 O6 5′ N 4′ ¶ 156 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 8a 1 1′ 8′ a 28 Monospiro systems containing identical fused components are given “Spirobi-” names. The component name is bracketed if it is preceded by locants or is itself made up of fusion components. Added hydrogen is cited in parentheses following the spiro locants. Examples: 7′a 1′ 2,2′ -Binaphthalene 5′ 5 4 4′ 1′ 7′ 6′ 1 6 7 4 N 3′ 4 3 3,3′ -Spirobi[3H-indole] 5,5′ -Bibicyclo[2.2.1]hept-2-ene (not 2,2′ -Bibicyclo[2.2.1]hept-5-ene) 4′ 4′ N 1 7a 3′ 3′′ 1′′ 1′ 1 1,1′ :2′ ,1′′ -Tercyclopropane 3 8 ′a 1 8 2 5 4 1′ 2′ 4′ 5′ 2,2 ′ (1 H ,1 ′ H ) -Spirobinaphthalene 2 H N 1 HN 5 5′′ 1′′ H N 2′′ NH 4,4′ :4′ ,4′′ -Terpyrazolidine Di-, tri-, etc., spiro systems containing at least one fused or bridged component are named by extension of these policies. If terminal components are identical, citation is determined by earliest index position of the complete name. Serially primed locants are used for successive components. “Branched” polyspiro systems in which a single component is surrounded by three or more identical components are named by citing the central component (which is assigned plain locants) first and multiplying the identical (terminal) components. When two terminal components of a “branched” spiro system are identical, and one different, they are cited in alphabetical order (as usual) and the term “bis” is applied as appropriate. Examples: 1 8 9 3 1′ 4′ 5 3′ 1′′ 4′′ 5′ HN 2′ 1′ NH 1 5 1′ 5′ 1′′ 5′′ 1′′′ 5′′′ 3,3 ′:5 ′,3 ′′:5 ′′,3 ′′′-Quatercyclopentene Dispiro[bicyclo[3.3.1]nonane − 3,1 ′− cyclobutane − 3 ′ ,1 ′′− cyclo − butane] Indicated hydrogen (¶135) is assigned, where possible, to points of attachment. When indicated hydrogen is cited in different positions for different components, a ring-assembly name is not used. Added hydrogen (¶ 135) is cited immediately after the locant to which it relates. Example: 1 1′ 2 2′ N 5 1′′ N 5′ N N 3 N N 3′ 6′′′ 1′′′ 6′′ 7′′a O 3′′ 4′′ 3′ 2′ 6 5′ 1′ 1 5′′ Trispiro[cyclohexane -1,1 ′- cyclo pentane−3′,3′′(2′′H)−cyclopenta− [ b ]pyran − 6 ′′ (4 ′′ H ),1 ′′′− cyclo − hexane] 2,2′ -Bi-2H-1,2,3-triazole H N 4′ H N N N1 NH 23 H N 3′ O 7′′′a 1′′′ 2′ 1 2′′′ 3′′′′ 3 2 2′′ 1H-Benzotriazole, 1-(1,3−dihydro2 H -benzotriazol -2 -yl) -2,3 -di hydro - (not 1 H -Benzotriazole, 2-(2,3-dihydro-1 H-benzotriazol-1yl)-2,3-dihydro-; not 1(3 H ),2 ′ B i -2 H -b e n z o t r i a z o l e , 1 ′ , 3 ′ dihydro-) 2(1H),4′ -Biisoquinoline O O O 1′ 3′′ 7′a 4′′ N N O 4′′′ O 1′′ 7′′a Trispiro[cyclopropane-1,2′ :2,2′′ :3,2′′′ -tris[1,3]benzodioxole] 5′′ 1′′ O 3′′ O 7a 2′′ 3′′′ O 2′′′ 4′ 1′′′ 5′′′ O 1 2 2′ 1′ O Trispiro[1,3 -benzodioxole -2,1 ′ c yclohexane -2 ′ ,2 ′′ :4 ′ ,2 ′′′ -bis [1,3]dioxolane] O3 4 6′ Linear benzene assemblies (polyphenyls) are named by prefacing “phenyl” with the appropriate term (Bi-, Ter-, etc.). Arabic numeral locants are cited in all cases for points of attachment. Two-component assemblies of monocyclic hydrocarbons and of hetero systems with “cyclo” names, e.g., Cyclopentastannane, Cyclotrisiloxane, and monocycles with one silicon using “sila” names, are named from the radicals, and locants for the points of attachment are cited only when the radical has no locant for the free valency. Two-component ring-assembly names from unsaturated (“-enyl”) radicals are formed only when the unsaturation is symmetrical with respect to the points of attachment. Examples: 6 1 1′ 157. Ring assemblies contain a multiplicity of the same cyclic system joined by single bonds, not necessarily in equivalent positions. They are treated as molecular skeletons in substitutive nomenclature and rank just above the component ring. Except for assemblies of benzene, and two-component assemblies of cycloalkanes, cycloalkenes, and hetero systems with “cyclo” names (see below), they are named by prefixing the component names with the terms Bi-, Ter-, Quater-, Quinque-, Sexi-, Septi-, Octi-, Novi-, Deci-, Undeci-, etc. Locants are placed ahead of the name to define the points of attachment. These locants are as low as possible, compatible with fixed numbering (expressed or implied) of the components, including “-ene” and “-yne” suffixes. Examples: 2,2′ -Bipiperidine 1,1′ -Biphenyl 6′ 6′′′′ 1′′′′ 6′′′ 1′′′ 6′′ 1′′ 6′ 1′ 1 6 1,1′:4′,1′′:4′′,1′′′:4′′′,1′′′′- Quinquephenyl 6 6′ 1′ 1 1′ 6′ 1 6 1,1 ′ -Bicyclohexyl (not Bicyclohex − 1-yl) N H N H 29 6′ 1′ 1 6′ Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Bi-2-cyclohexen-1-yl (not 1,1′-Bi2-cyclohexen-1-yl) Cl 1′ ¶ 158 Te Cl H2 Si 7 1 O 8 O H 2 Si 3O H Si 2′ O 3′ O H2 8′ Si O 7′ 6′ 5H-5λ4-Dibenzotellurophene, 5,5-dichloroBicyclotetrasiloxan-2-yl • A radical is formed according to the established rules–including the use of added hydrogen to accommodate an “ylidene” radical–when the free valence is on the nonstandard heteroatom. Cyclohexene, 1- (3- cyclohexen- 1yl) - (not Cyclohexene, 4-(1cyclohexen-1-yl)- (lowest locant for the substituent prefix is preferred (¶ 138)) N Me S SO 2 Me H 2Si 6 5 3 11 6 4 O Si H2 Si H2 4′ Si H2 O 5′ 6 158. Nonstandard heteroatoms in CA ring nomenclature. Additive terms are used to describe oxides, sulfides, selenides, and tellurides of ring heteroatoms: 7a Me O2 S 1 3 Benzo[ b ]thiophene, 3,5 -dimethyl 1,1-dioxide Me Benzenesulfonamide, N-(3,4-dihydro-5,6-dimethyl1λ4-thiopyran-1(2H)-ylidene)- Me 4 O N 6 1 H N Me P P Me H N SCH2 CO 2H Acetic acid, 2-[(1-oxido-2-pyridinyl) thio] - N H N H For all other neutral ring heteroatoms with nonstandard bonding numbers (hereafter referred to as nonstandard heteroatoms), the IUPAC lambda convention (Pure Appl. Chem. 1984, 56, 769-778) is used, regardless of the heteroatom in question, its bonding number, or the kinds of bonds joining it to other skeletal atoms. The rules are as follows: • The λ term is prefixed to the name for the ring parent, preceded by the locant for the nonstandard heteroatom–in a fusion name, that locant is for the fused ring system, not a component ring–and followed by a superscript denoting the nonstandard valence. (In the IUPAC recommendations, the λ is usually inserted within the ring name, after the locant for the nonstandard heteroatom.) Me O S O Me 2λ5-1,3,2-Diazaphospholidine, 2-methyl-2-(2-methyl-2λ5-1,3,2diazaphospholidin-2-ylidene)- N HP N P H2 PH N 2λ5,4λ5,6λ5-1,3,5,2,4,6-triazatriphosphorine-2,4-diyl • After the established rules for low numbering have been applied–for heteroatoms, indicated hydrogen, an onium center, and so on–low numbering is assigned to a nonstandard heteroatom in preference to the same heteroatom with the standard bonding number. S 6 5 4 3 1 2 2λ4-1,3,2-Dioxathiane, 2,2-dimethylH N P N H NEt 2 I NEt 2 S H 1λ4-1,5-Benzodithiepin • In a bridged fused ring system, the name of the bridge (including its locants and any indicated hydrogen required by the bridge) is prefixed to the fusion name with its λ term. S N 2λ5-1,3,2-Diazaphospholidine-2,2-diamine, N,N,N ′,N ′-tetraethyl-2-iodoF I O F F N S Me Me 1λ5-1,2-Benziodoxole, 1,1,1-trifluoro-1,3-dihydro-3,3-dimethylH S 5 1,4-Methano-5,11-nitrilo-11H-5λ4,11λ4dibenzo[c,f][1,5,2]dithiazepine • In a ring assembly or spiro name, the component name is always cited with its own λ term. Cl N Cl P6 N5 Cl 1 2P 3 N 12 4 3N Et Me N P 2′ N 3′ Cl 1′ 4′ Cl 6′ P 5′ N 1λ4-Pyrido[2,3-e]-1,3-thiazine • For a ring parent with the maximum number of noncumulative double bonds, indicated hydrogen is used with a nonstandard heteroatom if that atom is joined to other skeletal atoms only by single bonds–unless the other atoms are divalent, in which case indicated hydrogen is not used. Indicated hydrogen always precedes the λ term. Cl 4 N P Cl P Cl 2,2′-Bi-2λ5,4λ5,6λ5-1,3,5,2,4,6-triazatriphosphorine, 4,4,4′,4′,6,6,6′,6′-octachloro-2-ethyl-2′-methyl- ¶ 158 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 O 1 4 2 30 N P 2′ 1′ N 3 N Spiro[2λ5-1,3,2-benzoxazaphosphole-2,2′[2H-2λ5-1,3,2]diazaphosphole] S 1 3′ 2 Te 2 ′ 3 1′ S S S 2,2′-Spirobi[2λ4-1,3,2-benzodithiatellurole] • In a replacement name for a saturated ring parent, both the lambda convention and subtractive suffixes are used to describe a nonstandard heteroatom joined to cumulative double bonds. S 61 2 543 Until structures have been determined, author terms such as “iso” and “neo” are cited in index modifications to differentiate isomers. Numbering of polyboranes in CA indexing is based on “Nomenclature of Boron Compounds” adopted by the American Chemical Society, and “Nomenclature of Inorganic Boron Compounds”, published by the International Union of Pure and Applied Chemistry,1 which may be consulted for further details. For “closed” polyboranes (those whose boron skeletons are polyhedra with triangular faces throughout) the numbering begins with the boron atom at the head of the largest axis of highest order, then proceeds sequentially to the planes which intersect this axis. Boron atoms in each plane are numbered clockwise unless lowest locants for substituents demand anticlockwise numbering. On succeeding planes, numbering begins at the boron atom immediately “below” the lowest-numbered one on the previous plane, or the one nearest to it in the direction of numbering. Example: H1 B 5 4 HB B H 3BH 2 BH 9 H B 2 6 Si H2 HB BH 1λ4-1-Thia-4-silacyclohexa-1,6-diene H HB B 9 5 5 1 3 HB BH 6 BH BH • To describe all other nonstandard heteroatoms joined to cumulative double bonds, the lambda convention is used together with the IUPAC delta convention (Pure Appl. Chem. 1988, 60, 1395-1401). The terms are combined into a single expression, prefixed by the locant for the nonstandard heteroatom. The number of cumulative double bonds to the nonstandard heteroatom is specified by a superscript Arabic numeral after the δ. S 1 2 3 B H7 HB 8 BH 7 4B B 10 H Decaborane(10) planar projection H N N (Note that atom “6” (in the lower plane) is nearest to atom “2” in the direction of numbering.) For “open” polyboranes (those with incomplete polyhedral boron skeletons) the rules are more complex. A planar projection, as viewed from the open side, is numbered so that interior boron atoms have lowest locants, beginning at the “center” or “apex.” Each atom set is numbered in the same direction. Examples: H2 B SH 1 1λ4δ2-1,2,3-Thiadiazole N 6 7 S 5 4N 3 N8 1 2 Diborane(6) H S N H 2 1λ4δ2,3λ4-1,3,5,2,4,6,8-Trithiatetrazocine B H2 H B 1 S H HB H HB 4 5 H B 2 5 H 3 1 2N 43 BH H 3 2 N S 1′ H BH HB H 1 H B 4 BH H B H Spiro[3λ 6δ2-1,3,2,4-benzodithiadiazine-3,1′-[1H-1λ6]thiophene] Pentaborane(9) BH H H 1 H planar projection H B 2 1 159. Boron molecular skeletons. Because the number of hydrogen atoms in neutral and anionic boron hydrides often bears no simple relationship to the number of boron atoms, borane names must express the number of both. (The single exception is Borane itself, which represents BH3.) The Ring Systems Handbook should be consulted for structural diagrams of the neutral polyboranes of established structure. Diagrams justified by current index entries are displayed in the Chemical Substance Indexes. (In these diagrams, the lines do not represent electron-pair bonds but indicate the geometry of the structures.) Neutral boron hydrides, real or hypothetical, are treated as molecular skeletons in substitutive nomenclature, Borane and the diboranes as heteroacyclic compounds, and the higher hydrides as heterocyclic compounds. Borane(1) is BH, Borane(2) is BH2. In higher boranes, the number of boron atoms is expressed by multiplicative prefixes. Examples: B2H4 B2H6 B3H7 B4H10 B5H9 B6H10 B10H14 H HB 6 H 3 BH H BH HB 6 2 HB 5 4 BH 3 BH BH H 5 4 H H B H B H Hexaborane(10) planar projection Some polyboranes can be named as derivatives of simpler polyboranes. Thus, a bimolecular polyborane, i.e., a two-component “ring” assembly in which both skeletons are identical, can be named as follows: 1,1′ -Bipentaborane(9) When the various parts of the structure are not identical, the general principles of substitutive nomenclature are applied, and a polyborane radical is used for the less preferred skeleton, e.g., Decaborane(10), 2-octaboran(8)-1-yl-. Polyboranes joined along an edge, or with a triangular face in common, are named like fused ring systems; e.g., Decaborano(14)[5′ ,6′ :5,6]decaborane(14), Undecaborano[2′ ,7′,11′ :1,2,3]dodecaborane(17). Diborane(4) Diborane(6) Triborane(7) Tetraborane(10) Pentaborane(9) Hexaborane(10) Decaborane(14) 1Inorg. Chem. 1968, 7(10), 1945-65; Pure Appl. Chem. 1972, 30(3-4), 683-710. 31 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 161 160. “Hetero” polyboranes are boron hydride skeletons in which boron atoms have been replaced by those of other elements, notably carbon. Replacement prefixes, e.g., “carba,” “phospha,” are employed with the polyborane name, and the number of hydrogen atoms attached to the skeleton expressed in parentheses after the name. Structural diagrams for compounds of established structure can be found in the Ring Systems Handbook and, when justified by current entries, in the Chemical Substance Index. Numbering is as for the parent polyboranes, with lowest compatible locants assigned to the replacement atoms. Examples: H C 1 multiple) in one or two positions of an acyclic chain are always terminal, otherwise a compound radical name is employed. When three or more positions have free valencies, two of them must be terminal. Examples: MeCH2− H2C= CHCH2− EtCH= PrC≡ H2C= C= ethyl 2-propen-1-yl (not allyl) propylidene butylidyne ethenylidene 2-propen-1-ylidene 2-hepten-5-yn-1-ylidene 1,2-ethanediyl 1-ethanyl-2-ylidene 1,2-ethenediyl 1,3-propanediyl 1,2-propadiene-1,3-diylidene 1,2,3-propanetriyl 1,3-propanediyl-2-ylidene BH HB 5 6 CH H B 3 2 H B 4 1,2-Dicarbadodecaborane(12) H2C= CHCH= MeC≡CCH2CH= CHCH= −(CH2)2− H B HB 9 10 H B 11 H8 B 12 7 BH −CH2CH= −CH= CH− −(CH2)3− = C= C= C= | —CH2CHCH2— B H H B 1 HB 6 5 4C B H H B 2 CH H 3 2,4-Dicarbaheptaborane(7) || —CH2CCH2— 7 B H (c) Organic heteroacyclic (“a”) radicals are used when the requirements ( ¶127) are met. The numbering of the parent radical is retained. A single free valency is hence always in the 1-position, and this locant is always cited. When there is still a choice, lowest locants are assigned to hetero atoms, then to most preferred hetero atoms (Table I, ¶ 128), then to unsaturation (with double bonds preferred). Examples: Me[O(CH2)2]3 OCH2CH2− 161. Substituent prefixes (radicals) derived from molecular skeletons are used very frequently in substitutive nomenclature. Their names are based on the skeleton names and may be classified accordingly as radicals from (a) monoatomic skeletons, (b) hydrocarbon chains, (c) organic hetero (“a”-named) chains, (d) homogeneous hetero chains, (e) heterogeneous hetero chains, (f) carbocycles, (g) heterocycles, (h) ring assemblies, (i) polyboranes. Combination of simple radicals to form compound and complex radicals is performed by application of principles described earlier (¶ 133). (See also “Illustrative List of Substituent Prefixes,” which constitutes Section H (¶ 294). (a) Monoatomic radicals from borane, methane, silane, germane, stannane, and plumbane are named by replacing “-ane” by “-yl,” “-ylene,” and “-ylidyne” to denote the loss of one, two, or three hydrogen atoms. The final “e” of the hydrides arsorane and phosphorane may be replaced by “-yl,” “-ylidene,” and “-ylidyne.” Stibine and bismuthine may have the “-ine” ending replaced by “-ino,” “-ylene,” and “-ylidyne.” Phosphine and arsine may have the “-ine” replaced by “-ino,” “-inidene,” and “-inidyne.” The -tetrayl suffixes indicate loss of all hydrogen from Group IVA monoatomic hydrides. Examples: H2B− H2C= =Sn= H2P− HP= P≡ H4P− H3P= H2P≡ H2As− HC≡ HSi≡ HAs= As≡ H2Sb− HSb= Sb≡ H2Bi− HBi= Bi≡ 3,6,9,12-tetraoxatridec-1-yl (not [2-[2-[2-(2-methoxyethoxy)ethoxyl]ethoxy]ethyl]) 2 1 MeSiH2CH2SiH2CH= CHSiH2CH2SiH2CH= 10 9 7 4 2,4,7,9-tetrasiladec-5-en-1-ylidene —CH2CH2[S(CH2)2]2SCH= CHNHCH2CH21 2 9 12 14 3,6,9-trithia-12-azatetradec-10-ene1,14-diyl (d) Homogeneous heteroacyclic radicals are named analogously to acyclic hydrocarbon radicals, except that only the “e” of “ane” suffixes of heteroacyclic skeleton names is replaced by “-yl.” Examples: HN= N− diazenyl (also used for the substituted radical, rather than azo) triazanyl 2-triazen-1-yl 1,3-pentazadien-1-yl diphosphinyl 1,2-diphosphinediyl 1,2-diarsinediylidene 1,2-distibenediyl hydrazinyl (not hydrazino) hydrazinylidene (not hydrazono) 1-hydrazinyl-2-ylidene 1,2-hydrazinediyl (not hydrazo or hydrazi) 1,2-diazenediyl (not azo or azi) 1,2-hydrazinediylidene (not azino) boryl methylene stannanetetrayl phosphino phosphinidene phosphinidyne phosphoranyl phosphoranylidene phosphoranylidyne arsino methylidyne silylidyne arsinidene arsinidyne stibino stibylene stibylidyne bismuthino bismuthylene bismuthylidyne H2NNHNH− HN= NNH− H2NN= NN= N− H2PPH− −PHPH− = AsAs= −Sb= Sb− H2NNH− H2NN= −NHN= −NHNH− (b) Acyclic hydrocarbon radicals are named from the skeletons by replacing “-ane,” “-ene,” and “-yne” suffixes by “-yl,” “-enyl,” and “-ynyl,” (for monovalent radicals); by “-diyl,” “-triyl,” “-enediyl,” “-ynediyl,” etc., for divalent radicals with hydrogen removed at more than one position; and by “-ylidene” and “-ylidyne” to indicate two or three hydrogen atoms lost at one position. (Methylene is an exception.) Locants are not cited for monovalent radicals (the free valency position is always “l”), but unsaturated positions are always indicated for chains of three or more atoms. Free valencies (single or −N= N− = NN= ¶ 161 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 7a 1 32 (e) Heterogeneous heteroacyclic radicals are named analogously to hydrocarbon radicals. Examples: 4 1H-inden-2-yl 3 H3SiOSiH2− H3SiOSiH= H3SnOSn≡ −SiH2NHSiH2− 1-disiloxanyl 1-disiloxanylidene 7a 1 1-distannoxanylidyne 1,3-disilazanediyl 1,3,5-trisiloxanetriyl 4 3 3aH-inden-3a-yl (a hydro derivative would be named, e.g., 2,3-dihydro3aH-inden-3a-yl, not 2 H-inden3a(3H)-yl) | —SiH2OSiHOSiH2— 10 9 11a 1 (f) Cyclic hydrocarbon radicals. Loss of one or two hydrogen atoms from a single cycloalkane carbon atom is denoted by replacement of “ane” of the ring name by “-yl” and “-ylidene,” respectively. The implied locant (“l” in all cases) is not expressed. In radicals from cycloalkenes, cycloalkadienes, etc., only the final “e” is replaced by the radical suffix, and locants for unsaturation and the free valency (always “l”) are all cited. Loss of hydrogen at more than one position is expressed by the suffixes “-diyl” (not “-ylene”), “-diylidene,” “-enylylidene,” etc. All locants are cited, and locants for free valencies are assigned lowest locants. Examples: 1 6 5H-dibenzo[a,d]cyclohepten-5-ylidene 4 6 9 8 4b 4a 10a 1 2,7-phenanthrenediyl cyclohexyl 8a 1 3-naphthalenyl-1(4 H)-ylidene (not 2-naphthalenyl-4(1H)-ylidene) 5 4 1 3 2-cyclopropen-1-yl Von Baeyer and spiro radicals follow similar principles. Free valency locants are assigned lowest locants compatible with ring-system numbering and are preferred over locants for unsaturation. Examples: 2,4-cyclopentadien-1-yl bicyclo[2.2.2]oct-5-en-2-yl (not bi cyclo[2.2.2]oct-2-en-5-yl) 1 5 1 6 1,5-cyclohexadien-3-yn-1-yl 8 1 9 5 1 6 bicyclo[3.3.1]nonane-2,3-diyl-4ylidene 2,4-cyclohexadien-1-ylidene 11 12 7 5 1 dispiro[]dodec-2-yl 1 5 1,3-cyclopentanediyl (not 1,3-cyclopentylene) 6 1 72 1′ 6′ 4 spiro[bicyclo[2.2.1]hept-5-ene-2,1′[3,5]cyclohexadien]-2 ′ -yl (note: lowest locants are assigned, in order, to spiro atoms, free valencies, all multiple bonds, double bonds) 1 6 1-cyclohexanyl-2-ylidene (not 1cyclohexyl-2-ylidene) (g) Heterocyclic radicals from ring systems not named by organic replacement (“a”) nomenclature are named analogously to fused-hydrocarbon radicals (above). The shortened form thienyl is used for thiophene radicals and all their fused derivatives; selenophene-yl (not selenophenyl) is the name of the seleno analog. Examples: 1 6 1 6 6-cyclohexen-1-yl-2-ylidene N 3-pyridinyl (not 3-pyridyl) Radicals from benzene are named phenyl (C6H5-), 1,2-, 1,3-, and 1,4phenylene (-C6H4-), 1,2,3-benzenetriyl, 1,2,3,4-benzenetetrayl, etc. Fused hydrocarbon radicals are assigned the lowest locants compatible with the fixed numbering of the ring system. Indicated hydrogen (¶ 135) necessary for the existence of the ring is assigned to the lowest nonangular position unless it can be located to accommodate a monovalent radical in an angular position or an “ylidene” radical in a nonangular position. Added hydrogen (¶ 136) is cited immediately after the radical locant and is assigned the lowest available angular or nonangular position. Examples: 8a 1 6 N 1 1(2H)-pyridinyl 1 6 O 4 4-morpholinyl (not morpholino) N 2-naphthalenyl (not 2-naphthyl) 4 4 7a S 3 1 5 benzo[ b]thien-2-yl (not benzo[ b]thiophen-2-yl) 33 7a Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 N 3 1 ¶ 162 4 3H-indol-2-yl-3-ylidene (a hydro derivat would be named, e.g., 1,2-dihydro3H-indol-3-ylidene, not 1H-indol3(2H)-ylidene) 6′ 1′ 1 [bi-2,5-cyclohexadien-1-yl]-4,4 ′ diylidene 6 1 5 O 2,5-furandiylidene (i) Polyborane radicals are formed from polyborane and hetero polyborane names by citing the usual radical suffixes after the parenthetical designation of the number of hydrogen atoms, with elision of the final “e” before “y.” Requirements for locant citation with diborane radicals are the same as for the analogous acyclic hydrocarbon radicals. Examples: diboran(4)yl diboran(6)yl diboran(4)ylidene 1-pentaboran(9)yl 1,2-dicarbadodecaboran(12)-1-yl 6,9-decaborane(10)diyl 1 7a N N3 2H-benzimidazol-5-yl-2-ylidene 4 1 6 O 2 H Si 5O 4 SiH O3 cyclotrisiloxane-2,4,6-triyl 1,2-diborane(4)diyl 162. Compound and complex radicals from molecular skeletons are named by principles described earlier (¶ 133). Examples: Me2CH− H2C= CMe− Si H “A”-named cyclic radicals are named like the hydrocarbon parents from which they have been derived by atom replacement. The hetero atoms receive lowest locants (cited or implied), then the free valencies (cited just ahead of the radical suffix). Examples: H2 Si 6 1 (1-methylethyl) (1-methylethenyl) (the unsaturated parent radical is preferred) silacyclohex-2-yl (not 2-silacyclohexyl) CH= CH−C≡C−CH3 | CH3−CH= CH−CH= CH−CH−CH= CH−CH= CH−CH2— 11 10 9 8 7 6 5 4 3 2 1 [6-(1-penten-3-yn-1-yl)-2,4,7,9-undecatetraen-1-yl] PhCH= CH− 1 6 5 (2-phenylethenyl) (not styryl) (phenylmethylidyne) (not benzylidyne) O3 3-oxabicyclo[3.1.0]hex-6-ylidene PhC≡ (h) Ring-assembly radicals are derived by bracketing the assembly name, eliding a final “e” if “y” is to follow, and appending the radical endings “-yl,” “-ylidene,” “-diyl,” etc., as appropriate. The free valencies need not be on the terminal rings of the assembly. Examples: 6′ 1 1′ 6 Me 1 6 (2-methylphenyl) (not o-tolyl) [1,1′ -biphenyl]-4-yl (not 4-biphenylyl) 1 6 4-methyl-1,2-phenylene) (not 4methyl-o-phenylene) Me 6 1 1′ 6′ [1,1′ -biphenyl]-2,4′ -diyl (not 2,4 ′ biphenylylene) 6′ 1′ 1 6 6′ 1′ 1 6 1′′ [1,1 ′ -biphenyl]-3,4-diyl (not (4phenyl-1,2-phenylene)) [1,1 ′:3 ′,1 ′′ -terphenyl] -4,4 ′ -diyl (not (2-phenyl[1,1′-biphenyl]-4,4 -diyl)) ′ Radicals from branched polyphenyls are chosen by application of the following principles successively until a decision is reached: (a) longest chain of rings containing all of the free valencies, which need not be on terminal rings; (b) lowest locants in the radical name for (1) ring junctions, and (2) free valencies; (c) maximum number of substituent prefixes; (d) lowest locants for substituent prefixes; (e) earliest index position of the radical name. Examples (the letters on the left refer to the principles above): (a) 1′′′′ 1′′′ 6′′′′ 6′′ (3 ′′ ,6 ′′ -diphenyl[1,1 ′ :4 ′,1 ′′ :2 ′′ ,1 ′′′ :4 ′′′ ,1 ′′′′ -quinquephenyl]-4 ′′ ,5′′ -diyl) 8 ′a 1′ 1 4 5 1′′ 6′′′ 6′ 1′ 1 [1,2′ -binaphthalene]-4′ ,5-diyl 6′′ 5′ 4′ 8a 6 S 3′ N 1′ 5′ 5 1 S [5,5′ -bithiazol]-2-yl (not [5-(5-thiazolyl)-2-thiazolyl]) N3 (b) (1) 6′′ 1′′ 1′′′ 6′′′ 6 1 1′ 6′ 1′ 6′ 1 N N 6 [2,2 ′ -bipyridine]-4,6-diyl (not [6-(2pyridinyl)-2,4-pyridinediyl]) (4 ′′ ,5 ′ -diphenyl[1,1 ′ :2 ′ ,1 ′′ :2 ′′ ,1 ′′′ quaterphenyl]-3′ -yl) ¶ 162 (b) (2) 6 1 6′ 1′ Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 [6′ -(4-methylphenyl)-4′ ,5′ -diphenyl[1,1′ :2′ ,1′′ -terphenyl]-3′ -yl] 1′′ 6′′ 34 Example: [1,1′:2 ′,1 ′′-Terphenyl]-3 ′-carboxylic acid, 4′′ -bromo -3 -fluoro -4′ ,6′ diphenyl- (a decision is reached by choosing lowest locants for the Terphenyl skeleton and then for the principal group) Me CO2H Br 6’’ 6’ 6 1’ 1 1’’ (c) Cl [6′ -(2-bromophenyl)-4-(3-chlorophenyl)-2′′ ,4′′ -diiodo[1,1′ :2′ ,1′′ terphenyl]-4-yl] Br F 6′′ I 1′′ 1′ 1 6′ I 6 (d) 6′′ 1′′ 1′ 1 6′ [2′′ -chloro-6′ -(4-chlorophenyl)-4′ phenyl[1,1′ :2′ ,1′′ -terphenyl]-4-yl] Cl 163A. Fullerenes. The even-numbered, closed spheroidal structures of 20 or more carbon atoms, in which every atom is bonded to three other atoms and of which the C60 “buckminsterfullerene” is the prime example, as known generically as “fullerenes”.2,3 “Fullerene” has been adopted as the class name and to it are added ring sizes, number of carbon atoms, and point group symmetries to name specific members of the class. For example, in the name [5,6]FullereneC60-Ih, “[5,6]” indicates the presence of ring sized 5 and 6, “C60” the number of carbon atoms, and “Ih” the point group symmetry.4 When a fullerene is modified (e.g., by addition, replacement, or deletion of atoms), the ring sizes, the number of carbon atoms, and the point group symmetry remain those of the parent fullerene. Incompletely described fullerenes, i.e., where ring sizes and/or point group symmetries are not known or disclosed are named with only the number of carbon atoms, e.g., Fullerene-C60. Existing nomenclature practices are followed as closely as possible when naming derivatives. Anions, cations, protonated fullerenes, and free radicals are named as follows: [5,6]Fulleride(3-)-C60-Ih [5,6]Fullerene-C60-Ih ion(1+) [5,6]Fulleren-C60-Ih-1(2H)-ylium [5,6}Fulleren-C60-Ih-1(2H)-yl Cl 6 (e) Cl 6′′ 1′′ 1′ 1 6 6′ [2′′-bromo-6′-(2−chlorophenyl)-4′phenyl[1,1 ′ :2 ′ ,1 ′′ -terphenyl]-4yl](not [6′-(2−bromophenyl)-2′′chloro-4′-phenyl[1,1′:2′,1′′-terphenyl]-4-yl]) Metallofullerenes are compounds in which one or more metals are either trapped inside the fullerene or located outside without bonding directly to it. They are given fullerene names, with the metals cited by name in alphabetical order Example: [5,6]Fullerene-C60-Ih compd. with potassium (1:1), ion(1+) Partial hydrogenation of a fullerene is described by terms such as “hexatriacontahydro-”, while full saturation is implied by the name “fullerane”, e.g., [5,6]Fullerane-C60-Ih. Fullerenes containing substituents require that hydrogen be added before the substituents can be named.5 For example, C60F60 is named [5,6]FulleraneC60-Ih, hexacontafluoro- (the hydrogen being part of the parent name). C60Br2 is named as a dibromodihydrofullerene, and C60H6Ph6 is named as a dodecahydrohexaphenylfullerene. Addition of hydrogen is not necessary when a fullerene contains two functional groups, as in [5,6]Fullerene-C60-Ih-1,60-diamine. Modification of the fullerene network such that some carbon atoms no longer have a connectivity of 3 are named by using “homo”, “nor”, and “seco”, e.g., 1,2(2a)-Homo[5,6]fullerene-C60-Ih-2a-carboxylic acid. Replacement of a carbon atom by a trivalent hetero atom such as boron or nitrogen results in a free radical, e.g., 1-Bora[5,6]fulleren-C60-Ih-2- yl.5 Br 163. Molecular skeletons as index heading parents. These two entities coincide when no suffix, expressing a principal group, is added to the skeleton name, either because such a group is absent, or because it is attached to a hetero atom of the skeleton which changes it from a functional into a nonfunctional group. Examples: H3C−CH3 PhNO2 Ethane Benzene, nitro - (“nitro” is a mandatory prefix (¶ 132)) Piperidine, 1-hydroxy- (“hydroxy” is considered nonfunctional when attached to a hetero atom other than silicon) Ethanone,1-(trimethylsilyl)- OH N Me3SiCOMe Choice of a preferred index heading parent has already been described (¶ 138). In the case of a branched polyphenyl, the criteria are the same as for the derived radicals (¶ 162), except that principal groups replace free valencies. hollow network of 12 pentagonal and m hexagonal faces for a C20+2m molecule (Science 1991, 254, 1768-1770), but CAS also includes structures with 3-, 4-, and 7- through 10sided faces as fullerenes for purposes of naming. 4“Character Tables for Chemically Important Symmetry Groups”. In: F. A. Cotton, Chemical Applications of Group Theory. 3rd ed., John Wiley & Sons, 1990. Appendix IIA, pp. 426-435. 5International Union of Pure and Applied Chemistry, Nomenclature of Organic Chemistry, Sections A,B,C,D,E,F, and H, 1979 ed., Pergamon Press, Oxford (England), 1979. Rules C-0.1 and C-32. 2Science 1988, 242, 1017-22; 1139-1145. 3“Fullerene” has also been defined as a closed, 35 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 C. PRINCIPAL CHEMICAL GROUPS (SUFFIXES) ¶ 165 Introduction Acids expressed as substituent suffixes Acyclic acids with cyclic substituents Order of precedence of acids Acid radicals Functional derivatives of acids Acid halides ¶ 164 165 166 167 168 169 170 Amides Nitriles Aldehydes Ketones Alcohols (and phenols) Amines Imines ¶ 171 172 173 174 175 176 177 164. Introduction. In substitutive nomenclature, a principal chemical group is that substituent of a molecular skeleton which is selected for expression as a suffix. Only one kind of substituent may be cited as a suffix, viz., the most senior one as determined by the Order of Precedence of Compound Classes (¶ 106); all other substituents are expressed as prefixes (radicals) which may be simple, compound, or complex (¶¶ 132, 133). For functional compounds, the molecular skeleton name together with its suffix constitutes an index heading parent. The locants for suffixes are placed in front of the heading parent name unless locants for indicated hydrogen, hetero atoms (in “a” names), unsaturation, fusion sites, etc., are present, in which case they are placed just before the suffix. In the following paragraphs, compound classes expressed as substituent suffixes are discussed in descending order of precedence. 165. Acids expressed as substituent suffixes on molecular skeletons include carboxylic, sulfonic, sulfinic, selenonic, and telluronic acids and their functional replacement analogs, such as peroxy, imidic and thio acids. For Carbonic acid and its relatives (including Carbamic acid and Formic acid) see ¶ 183. (a) Carboxylic acids are named by the Geneva (“-oic”) or “-carboxylic” system. The “-oic acid” suffix is employed for acyclic mono- and dicarboxylic acids of carbon chains, including “a”-named acids; the “-carboxylic acid” suffix is used for acyclic polycarboxylic acids and compounds in which the carboxyl group is attached to a ring, a monoatomic hydride, or a heteroacyclic chain. The trivial names Acetic acid and Benzoic acid are retained for these two acids and their substituted derivatives. (The amides, acid chlorides, etc., are named similarly, but organic replacement analogs are named systematically, e.g., Benzenecarboximidic acid (not Benzimidic acid.) Examples: MeC H 2 C O 2 H H 2 PCO 2 H Phosphinecarboxylic acid (not Formic acid, phosphino-) 1,3-Distannoxanedicarboxylic acid H O 2 CSn H 2 O Sn H 2 CO 2 H 1 2 3 H H2B H CO 2 H 1 6 BH CO 2 H Diborane(6)-1-carboxylic acid CO 2 H 2,6-Cyclohexadiene-1,2-dicarboxylic acid (lowest locants for principal groups are preferred) CO 2 H 8 9 9a 1 1-Anthracenecarboxylic acid 5 10a 4a 10 1 8a N 4-Quinolinecarboxylic acid 5 4 Propanoic acid (not Propionic acid) 5 CO 2 H Me(C H 2 ) 3 C O 2 H 5 1 Pentanoic acid (not Valeric acid) 3O 2 O 1 1′ 8′a Spiro[1,3-dioxolane-2,2′(1′H)naphthalene]-5′-carboxylic acid H 2 C =C H C O 2 H 3 1 2-Propenoic acid (not Acrylic acid) 4′ 5′ Me(C H 2 ) 4 C H =C HCH 2 CH= CH( CH 2 ) 7 CO 2 H 18 13 9 1 CO 2 H HO2C 6 1 1′ 6′ 9,12-Octadecadienoic acid Ethanedioic acid (not Oxalic acid) Pentanedioic acid (not Glutaric acid) 6 [1,1′-Biphenyl]-2,2′-dicarboxylic acid HO2CCO2H 12 CO 2 H H O 2 C (C H 2 ) 3 C O 2 H 1 5 CO 2 H N 1 H 3 C − C H 2 − O − C H 2 − CH 2 − O − CH 2 − CH 2 − O − CH 2 − CH 2 − O − CH 2 − CH = 23 21 18 15 12 11 10 ~~~ =CH − ( CH 2 ) 7 − COOH 9 1 ~~~ 1,4(4H)-Pyridinedicarboxylic acid (the added hydrogen is expressed after the final locant but relates to the 1-carboxyl group; see ¶ 136) CO 2 H 12,15,18,21-Tetraoxatricos-9-enoic acid (lowest locants are assigned to functional suffixes, not replacement prefixes) HO2C 1 2 CO 2 H B 1 0H 1 0 1,2-Dicarbadodecaborane(12)-1,2dicarboxylic acid (the 1,2-bond does not possess single-bond character) C O OH H O O C − C H 2 − C H − CH 2 − COOH 1 2 3 1,2,3-Propanetricarboxylic acid (numbering excludes the carboxyl groups) (b) Sulfonic, sulfinic and sulfenic acids and their selenium and tellurium analogs are expressed by appending the appropriate suffix to the name of the molecular skeleton. Mono- and diacids of these series, unlike “-oic acids,” above, do not need to occupy terminal positions on a chain. Examples: E tSO 3 H SO 3 H 1 − (H O 2 C ) 2 C =C (C O 2 H) 2 1,1,2,2-Ethenetetracarboxylic acid 1,2-Hydrazinedicarboxylic acid (not Bicarbamic acid) Ethanesulfonic acid HO2CNHNHCO2H 1 2 CH 3 − CH 2 − CH 2 − CH − CH 3 5 4 3 2 − 2-Pentanesulfonic acid ¶ 165 P hS O 3 H N 6 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Benzenesulfonic acid 6 1 36 N 3-Pyridinecarbohydrazonic acid 3-Pyridinesulfinic acid SO2H C( =N N H 2 ) O H 6 MeSO H Methanesulfenic acid 1-Triazene-1-sulfonic acid Hydrazinesulfinic acid − SO 3 H 1 H O C( = N H ) 1 C( = N H ) O H 1,4-Benzenedicarboximidic acid H2NN=NSO3H 32 1 8a 1 S( = N H ) O 2 H 2-Naphthalenesulfonimidic acid 5 4 H 2 N N H SO 2 H 15 C H 3 − C H 2 − O − C H 2 − CH 2 − O − CH 2 − CH 2 − O − CH 2 − CH 2 −Ο− C Η 2 − CH − CH 3 13 10 7 4 3 2 E tS( = N H ) 2 O H Ethanesulfonodiimidic acid 4,7,10,13-Tetraoxapentadecane2-sulfonic acid (principal groups are preferred over heteroatoms for lowest locants) H2PSO3H S( = N H ) ( = Ν N H 2 ) O H 2-Naphthalenesulfonohydrazonimidic acid E tS( = N H ) O H Ph Se ( = N H ) O 2 H Phosphinesulfonic acid Benzeneselenonic acid SeO2H − Ethanesulfinimidic acid Benzeneselenonimidic acid P hS eO 3 H C H 3 − C H 2 − C H 2 − CH 2 − CH − CH 3 6 5 4 3 2 1 2-Hexaneseleninic acid TeO2H CH3− CH2− CH−CH3 4 3 2 1 2-Butanetellurinic acid (d) Peroxy acids are named by use of the suffixes “-peroxoic acid” (from “-oic acid”) and “-carboperoxoic acid” (from “-carboxylic acid”). Acetic acid and Benzoic acid afford systematically named peroxy acids. Sulfonic, sulfinic, and sulfenic acids and their selenium and tellurium analogs are named by use of the suffixes “-sulfonoperoxoic acid”, etc. Combinations with imidic and hydrazonic suffixes are made, in alphabetic order, by the normal rules. Examples: CH 3 − C − O O H = Ο − P hT eO H Benzenetellurenic acid (c) Imidic and hydrazonic acids. Names for these are formed from the parent carboxylic, sulfonic, sulfinic, selenonic, etc., acid names by functional replacement nomenclature (¶ 129). Some modification of the formal endings is made; thus, an “-oic acid” becomes an “imidic acid”, not an “-imidoic acid”. Acetic acid affords systematically named Ethanoic acid replacement analogs, while Benzoic acid is treated as Benzenecarboxylic acid in a similar manner. The suffixes appended to the molecular skeleton name in each case are as follows: Parent Acid -oic -carboxylic -sulfonic -sulfinic Imidic acid -imidic -carboximidic -sulfonimidic -sulfinimidic Hydrazonic acid -hydrazonic -carbohydrazonic -sulfonohydrazonic -sulfinohydrazonic Ethaneperoxoic acid (not Peroxyacetic acid) Cyclohexanecarboperoxoic acid CO 3 H H O 3 C( CH 2 ) 2 CO 3 H Butanediperoxoic acid Ethanimidoperoxoic acid (not Peroxyacetimidic acid) Benzenecarboximidoperoxoic acid (not Peroxybenzimidic acid) M e C( = N H ) O O H Ph C( = N H ) O O H The group -S(:NH)2OH is named by the suffix “-sulfonodiimidic acid,” and -S(:NH)(:NNH2)OH by “-sulfonohydrazonimidic acid.” Selenium and tellurium acids are named analogously. Note: Imidic acids are tautomeric with amides; except for derivatives in which an acid proton has been replaced, e.g., esters and anhydrides, amides are preferred for index entries; see ¶ 122. Hydrazonic acids are tautomeric with hydrazides, which are preferred as index entries. Examples: MeC ( = N H )O H Ethanimidic acid (not Acetimidic acid) Benzenecarboximidic acid (not Benzimidic acid) Hexanimidic acid P hC ( = N H )O H Peroxy analogs of acids expressed as heading parents, e.g., Carbonoperoxoic acid (¶ 183), Phosphoroperoxoic acid (¶ 197), are ranked with the acids, e.g., Carbonic acid, Phosphoric acid, from which they are derived. (e) Thio acids derived from carboxylic, sulfonic, sulfinic, and sulfenic acids and their imidic, hydrazonic, and peroxy replacement analogs are named by incorporating “thio” (or “dithio”) into the suffixes of the oxygenated acid names. The terms “seleno” and “telluro” are used similarly when appropriate. Selenonic, telluronic, etc., acids are handled like sulfonic acids. The names do not distinguish between replacement of oxygen in =O and -OH groups in the unesterified acids. This information is usually given in the ester name, or by a substituent prefix. Examples: Ο = C − SCH 3 Benzenecarbothioic acid, S-methyl ester Me(C H 2 ) 4 C ( = N H ) OH 6 1 5 H N 1 S = C ( = N H) OH O = 2 1 1H-Pyrrole-2-carboximidic acid CH 3 CH 2 O − CCH 2 CH 2 C − O H 43 Butanoic acid, 4-ethoxy-4-thioxo- (for order of precedence of acid groups, see ¶ 167) H O C ( = N H )(C H 2 ) 4 C( = NH) OH H 2 N N H C ( = N H )O H Hexanediimidic acid Hydrazinecarboximidic acid Ethanehydrazonic acid MeC ( = N N H 2 )O H When a specific name for a single form is imperative, an italicized element symbol is used in the heading parent, e.g., Ethanethioic O-acid for CH3C(S)OH. Replacement by two sulfur atoms in a monocarboxylic acid named by the suffix “-oic acid” is denoted by the suffix “-(dithioic) acid” and by one sulfur atom in each of the two groups in a “-dioic acid” by “-bis(thioic) acid.” Ambiguity is absent from “-carboxylic” names, and parentheses are therefore not employed for the analogous “-carbodithioic acid” and “-dicarbothioic acid” suffixes. 37 Examples: Me(C H 2 ) 2 C O SH Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 167 Butanethioic acid 166. Acyclic acids with cyclic substituents may usually be named by conjunctive nomenclature (¶ 124). Examples: Ph CH 2 CH 2 CO 2 H β α Benzenepropanoic acid (not Hydrocinnamic acid) Benzeneacetic acid, α-methylene- (not Atropic acid) Benzeneacetic acid, α-(phenylmethylene)- (not Benzene-2-propenoic acid, α-phenyl-; conjunctive nomenclature is not used with unsaturated acyclic acids (¶ 124)) H2C=CHCS2H 3 1 2-Propene(dithioic) acid CH 2 C- CO O H α = P hC O SH Benzenecarbothioic acid (not Benzoic acid, thio-) 1-Piperidinecarbodithioic acid CS2H N CH = C − CO O H α H O S C C H 2 C O SH Propanebis(thioic) acid CH 3 CH 2 − CH − SO 3 H − α β Benzeneethanesulfonic acid, α-methyl- H S 2 C C H 2 C H = C H CH 2 CS 2 H 1 6 3-Hexenebis(dithioic) acid C O SH 8a 1 CH 2 SO 2 H C O SH 1,2-Naphthalenedicarbothioic acid 8a 1 1-Naphthalenemethanesulfinic acid 5 4 5 4 1,3-Benzenedisulfonothioic acid HSSO2 S O 2 SH 8 ( CH 2 ) 2 CO 3 H 9 9a 1 9-Anthracenepropaneperoxoic acid MeC H [S(S)SH ]Me 1 2 3 2-Propanesulfinodithioic acid Methanesulfenothioic acid 2-Thiophenecarboximidothioic acid 5 10a 4a 10 6 MeSS H 1 5 H O 2 C( CH 2 ) 2 1 ( CH 2 ) 2 CO 2 H 1,4-Benzenedipropanoic acid S C ( = N H )SH E tS( = N H )O S H Ethanesulfonimidothioic acid When different numbers of sulfur atoms replace oxygen in the functional groups of polyacids, the groups of higher sulfur content are expressed as substituent prefixes. Examples: ΗΟSCCΗ2CH2CO2H When conjunctive names are impermissible, e.g., for unsaturated and polyfunctional acyclic acids, acids attached to rings by a double bond, and acids of noncarbon chains, the cyclic group is expressed as a substituent. Examples: N 6 1 N H N H CO 2 H Hydrazinecarboxylic acid, 2-(2pyridinyl)- Propanoic acid, 3-(thiocarboxy)Acetic acid, 2-ethoxy-2-thioxo8 E tO SC C O 2 H − CH 2 CO 2 H CH CO 2 H 9 9a 1 Thio peroxy acids are named by similar principles; the replacement affixes “(thioperoxo)” and “(dithioperoxo)” are placed, in alphabetic order with other terms such as “imido” and “hydrazono,” in the “-oic,” “carboxylic,” “sulfonic,” etc., suffixes of the appropriate parent acids. Examples: MeC O S S H Butanedioic acid, 2-(9H-fluoren9-yl)- 4b 4a Epoxy derivatives of acids are named as oxirane and oxetane derivatives. Example: O Ethane(dithioperoxoic) acid Benzenecarboximido(thioperoxoic) acid 1,4-Piperazinedicarbo(dithioperoxo)thioic acid Benzenesulfono(dithioperoxoic) acid 2,3-Oxiranedicarboxylic acid (not Butanedioic acid, 2,3-epoxy-) CO 2 H P hC ( = N H )O S H HO2C 6 HS3CN 1 NCS3H P hS O 2 S S H SSSH N 6 1 1-Piperidinesulfeno(dithioperoxic) acid 2-Propanesulfeno(thioperoxoic) acid Ethaneselenoic acid Benzenecarboselenothioic acid MeC H MeSS O H 1 2 MeC SeO H P hC S eSH 167. Order of precedence of acids. Acid suffixes are the most preferred principal group of all non-cationic substituent suffixes (¶ 106), but only one type of acid suffix may be expressed in a heading parent. Less preferred acid functions are cited as substituent prefixes. The choice is made in accordance with the following hierarchy, listed in order of descending precedence: (a) Peroxy acids. (Among peroxy acids, the choice depends on the nature of the parent acid as described in (b) through (i), below.) (See also the separate ranking of peroxy carbonic and peroxy phosphorus acids at ¶¶ 183, 197.) (b) Carboxylic acids, followed by thio, seleno, and telluro analogs, in that order. The preferred acid group contains the maximum number of preferred chalcogens, oxygen being the most preferred. (For Carbonic acid, Formic acid, etc., see ¶ 183.) (c) Carbohydrazonic acids, followed by chalcogen analogs (see (b)). (d) Carboximidic acids, likewise. (e) Sulfonic acids, followed by chalcogen and nitrogen analogs in the order of (b), (c), and (d). (f) Sulfinic acids, likewise. (g) Sulfenic acids, likewise. (h) Selenonic, seleninic, and selenenic acids, as for sulfonic acids. (i) Telluronic, tellurinic, and tellurenic acids, likewise. ¶ 167 Examples: HO2C Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 H O C( = N H ) C( = N H ) — 38 (2-hydroxy-1,2-diiminoethyl) (2-naphthalenylcarbonyl) SO 2 OOH Benzenesulfonoperoxoic acid, 4carboxy- CO — S S H O − C − C H 2 − C H 2 − C − SH = = 1 2 3 4 Propanethioic acid, 3-(dithiocarboxy)- CO — (1,2-phenylenedicarbonyl) CO — CO2H 1 6 Benzoic acid, 3,4-disulfoSO3H SO3H NH O − C − C H 2 − COOH = 3 2 1 O —C — ([1,1′-biphenyl]-4-ylcarbonyl) (not (4-phenylbenzoyl) (see ¶ 133)) = Propanoic acid, 3-imino-3-phenoxy- — CS — — CS — (1,4-phenylenedicarbonothioyl) When two or more like acid groups are attached to different molecular skeletons, or when one or more are attached to a branched skeleton, the preferred index name is selected according to the usual rules (¶ 138). Examples: 6 N (3,5-pyridinediyldicarbonimidoyl) C( =N H ) Ph SO 2 — C( =N H ) HO2C 1 CH( CO 2 H) 2 Propanedioic acid, 2-(4-carboxyphenyl)- (principle: maximum number of the principal group) (phenylsulfonyl) (phenylsulfinyl) (S-phenylsulfinimidoyl) (phenylthio) Ph SO HO2C NHNHCO 2 H Hydrazinecarboxylic acid, 2-(3-carboxyphenyl)- (principle: hetero acyclic parent preferred) Ph S( = N H ) — Ph S— P hC H (C O 2 H )C H 2 Benzeneacetic acid, α-(cyclopentylmethyl)- (principle: preferred ring system) 1 O 3 Ph (C H 2 ) 3 CO 2 H CO2H 2-Oxiranebutanoic acid, 2-carboxy3-phenyl- (principle: largest heading parent) Propanoic acid, 3,3,3-trifluoro-2-methyl-2-(trifluoromethyl)principle: maximum number of substituent prefixes) 169. Functional derivatives of acids. In the absence of higher functions or more preferred compound classes (¶ 106), esters are indexed in the modification, usually at the acid name, sometimes at the alcohol (see ¶ 185). Hydrazides are likewise indexed at the acid name (¶ 189). Hydrazones, azines, and semicarbazones are named at hydrazonic acid parents (RC(OH):NNH2) (¶ 165). Oximes of carboxylic acids are given N-hydroxy imidic acid names; hydrates and acetals (ortho carboxylic acids and their diesters) are indexed as alcohols (or thiols). Examples: M e C( O H ) 3 1,1,1-Ethanetriol (not Orthoacetic acid) Ethanol, 1,1-dimethoxy- 3 − CH3 F 3 C − C2 C O O H − − 1 M e C( O M e ) 2 O H CF3 Aldehydic, amic, anilic, hydroxamic, hydroximic, nitrolic, and nitrosolic acids are indexed as compounds of mixed function (see ¶ 228). So are trivially named hydroxy and oxo acids, e.g., Glycolic acid, Acetoacetic acid, and amino acids, e.g., Sulfanilic acid, other than those which are of biological significance (¶ 205). 168. Acid radicals derived, by removal of hydroxyl groups, from acids expressed as suffixes are named as compound and complex radicals. Acyl radicals, e.g., propionyl, naphthoyl, acetimidoyl, are no longer used as substituent prefixes; the only exceptions in general index nomenclature are acetyl (CH3CO-) and benzoyl (C6H5CO-). Amino acid radicals, e.g., glycyl, L-alanyl, are restricted to use in peptide and depsipeptide names (¶ 206). Radicals derived from monocarboxylic acids are in general named as (1oxoalkyl) or (arylcarbonyl); carboximidic acids afford (1-iminoalkyl) and (aryliminomethyl) radicals; carbothioic acids give (1-thioxoalkyl) and (arylthioxomethyl) radicals (carbonimidoyl and carbonothioyl are used only as multiplicative radicals (¶ 125) and in cases where both bonds are attached to the same atom); sulfonic, sulfinic, and sulfenic acid radical names are based on the parent radicals “sulfonyl,” “sulfinyl,” and “thio.” Examples: E tC O — 170. Acid halides. In this category are now included the halogenides, in which the hydroxyl groups of acids are replaced by -NC, -NCO, -NCS, -NCTe, -N3, and (in acids other than carbon acids) -CN groups. They are named by placing the halide (etc.) term in the heading as a separate word following an acid term which ends as follows for various acid classes: Acid suffix -carboxylic -carbohydrazonic -carbothioic -carboximidic -oic -hydrazonic -thioic -imidic -sulfonic -sulfonimidic Examples: M e ( CH 2 ) 3 CO N CS Acid halide suffix -carbonyl -carbohydrazonoyl -carbothioyl -carboximidoyl -oyl -hydrazonoyl -thioyl -imidoyl -sulfonyl -sulfonimidoyl (1-oxopropyl) (1-thioxoethyl) (not thioacetyl) Pentanoyl isothiocyanate O 1 MeC S— 14 CH 3 − CH 2 − O − CH 2 − CH 2 − O − CH 2 − CH 2 − O − CH 2 − CH 2 − O − CH 2 − C − F 13 12 11 10 9 8 7 6 5 4 3 2 HN=CH— (iminomethyl) (not formimidoyl) (1,2,3-trioxo-1,3-propanediyl) (3-carboxy-1-oxopropyl) H 2 N N H CO Cl —C O C O C O — 3,6,9,12-Tetraoxatetradecanoyl fluoride Hydrazinecarbonyl chloride H O 2 C (C H 2 ) 2 C O — = 39 — C−NC = O Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Benzoyl isocyanide Examples: M e CO N H 2 2 1 ¶ 171 Acetamide Diazenecarboxamide Ethanethioamide Hexanedithioamide Propanediimidamide Benzenecarbohydrazonamide Methanesulfonodiimidamide P hC ( = N H )B r Benzenecarboximidoyl bromide H N = N H CO N H 2 P hC S C l Benzenecarbothioyl chloride M e CSN H 2 C H 3 − C H 2 − C H 2 − C H 2 − SO 2 − NCO 4 3 2 1 1-Butanesulfonyl isocyanate H 2 N CS( CH 2 ) 4 CSN H 2 1 6 H 2 N C( = N H ) CH 2 C( = N H ) N H 2 N1 N′1 2 3 N′3 N3 P hS (O )( = N H )C l Benzenesulfonimidoyl chloride Ph C( = N N H 2 ) N H 2 N′ N C lC O (C H 2 ) 2 C O C l 1 4 Butanedioyl dichloride (not Butanedioyl chloride) M e S( = N H ) 2 N H 2 SO 2 N H M e 8a 1 O C N S O 2 C H 2 (C H 2 ) 4 CH 2 SO 2 NCO 1 6 1,6-Hexanedisulfonyl diisocyanate 5 4 1,5-Naphthalenedisulfonamide, N1,N 5- dimethylM e N H SO 2 P hC H 2 C H 2 C O N 3 Benzenepropanoyl azide Ph CSN H Ph Benzenecarbothioamide, N-phenyl1H-Indole-3-ethanimidamide 3 Halides, etc., of peroxy acids are generally indexed as anhydrides, anhydrosulfides, etc., with halogen or halogenoid “oxo” acids such as Hypochlorous or Thiocyanic acid. Halides, etc., of (thioperoxy)sulfenic acids are indexed at Disulfide. Examples: 4 7a H N 1 CH 2 C( =N H ) N H 2 α N′ N C lC O SC l Carbonochloridothioic acid, anhydrosulfide with thiohypochlorous acid M e CO N H CO M e 2 1 N Acetamide, N-acetyl- (not Diacetamide) Benzenesulfonamide, N-(phenylsulfonyl)- (not Dibenzenesulfonamide) Ph SO 2 N H SO 2 Ph S = C−O−CN Benzenecarbothioic acid, anhydride with cyanic acid Amides of peroxy acids and thio peroxy acids are indexed as azanyl esters (¶ 193). Amide radicals are named as compound or complex radicals based on “amino” or “imino,” with acid radicals (¶ 168) as substituents. Examples: AcNH— S S Cl Disulfide, chloro 2-naphthalenyl Bz N = (acetylamino) (not acetamido) (benzoylimino) [(1-oxohexyl)amino] (not hexanamido) [(phenylsulfonyl)amino] (not benzenesulfonamido) [(iminophenylmethyl)amino] When more than one acid halide residue is present in a compound, only one type is named in the heading parent. This is chosen by consideration first of the hierarchy of the parent acids (¶ 167) and then, if a further choice is necessary, of the following list of halides and halogenides (in descending order of precedence): -F, -Cl, -Br, -I, -N3, -NCO, -NCS, -NCSe, -NCTe, -NC, -CN. Examples: FSO2 C OCl FSO2 F C O (C H 2 ) 2 C O I M e ( CH 2 ) 4 CO N H — Ph SO 2 N H — Ph C( = N H ) N H — Benzoyl chloride, 3,5-bis(fluorosulfonyl)- Butanoyl fluoride, 4-iodo-4-oxo- Functional derivatives of acid chlorides are indexed similarly to those of the parent acids (¶ 169). 171. Amides are named by modification of the parent acid suffixes, thus: -oic acid -carboxylic acid -carbohydrazonic acid -carbothioic acid -carboximidic acid -sulfonic acid becomes becomes becomes becomes becomes becomes -amide -carboxamide -carbohydrazonamide -carbothioamide -carboximidamide -sulfonamide The radicals above are employed as substituents when a more preferred amide or a higher function, e.g., an acid or acid chloride, is present in part of the molecule attached to the amide by way of the nitrogen atom. Other attachments call for use of amino and oxo, or (aminocarbonyl), (aminosulfonyl), etc., radicals. Examples: H 2 N CO ( CH 2 ) 2 CO 2 H 4 1 Butanoic acid, 4-amino-4-oxo- 6 1 CO 2 H Benzoic acid, 2-(aminocarbonyl)CO N H 2 6 Secondary and tertiary amides are named as primary amides with N-substituents. Anilides, toluidides, etc., are indexed as N-aryl amides. H 2 N SO 2 1 CO N 3 Benzoyl azide, 4-(aminosulfonyl)- ¶ 171 H 2 N C SC H 2 C O N H M e 3 1 N Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Propanamide, 3-amino-N-methyl3-thioxo+ − 40 The zwitterionic nitrilimines (R C ≡Ν −Ν − R ′) are named as substituted hydrazinium inner salts (¶¶ 201, 267). Examples: M e CN Acetonitrile 2-Penten-4-ynenitrile Ethanedinitrile (not Cyanogen) Germanecarbonitrile Hydrazinecarbonitrile 1,1,2,2-Ethenetetracarbonitrile Benzonitrile − CH 2 − CH 2 − CH 3 α A cN H S O 2 P h Acetamide, N-(phenylsulfonyl)H C ≡ CCH = CH CN 5 1 Replacement (“a”) nomenclature is employed where applicable (¶ 127) for naming polyamides, but not peptides (¶ 206). Example: N CCN H 2 N C O C H 2 C O N H( CH 2 ) 2 NHCOCH 2 CONH( CH2) 2 NHCOCH 2 CO N H 2 1 4 7 11 14 17 H 3 G e CN 4,7,11,14-Tetraazaheptadecanediamide, 3,8,10,15-tetraoxoAmides incorporated in a ring system are indexed at the ring name and ranked according to the nature of the suffix, if any (¶ 106), not as amides. Examples: Me 6 H 2 N N H CN ( N C) 2 C=C( CN ) 2 Ph CN H N 1 O 2-Piperidinone, 6-methyl- (ranked as a ketone) CH − CN Benzeneacetonitrile, α-propyl- 7a O2 S 2NH 3 1,2-Benzisothiazole, 2,3-dihydro1,1-dioxide (ranked as a nonfunctional cyclic nitrogen skeleton) In the presence of higher functions, nitriles are always expressed as cyano radicals. Examples: N CCH 2 CO N H 2 2 1 4 OH 1 7 O 2 Ph O 3 HN 5 1,3-Dioxolo[4,5-c]pyridin-4(3aH)one, tetrahydro-7-hydroxy-2phenyl- Acetamide, 2-cyano- (not Propanamide, 3-nitrilo-) Propanoyl chloride, 2-cyano- 4 M e CH ( CN ) CO Cl CO 2 H O Amides of which only the nitrogen atom forms part of a ring, formerly referred to as “unexpressed amides”, are named according to the highest function present. Examples: HO 1O 6 4 NCO 1 6 Benzoic acid, 2-cyanoCN 173. Aldehydes, RCHO, are named from “-carboxylic” and “-oic” acids by use of “-carboxaldehyde” and “-al” suffixes, respectively. Examples: A c H ( M e CH O ) Methanone, (2-hydroxyphenyl)4-morpholinyl- Acetaldehyde 2-Butenal 3-Octen-5-ynedial Phosphinecarboxaldehyde oxide M e CH =CH CH O A cN 1 6 1 OH Ethanone, 1-(4-hydroxy-1-piperidinyl)H CO CH 2 CH =CH C ≡ CCH 2 CH O 1 3 5 8 E tC O N 5 1 SO 2 NH 2 H 2 P( O ) CH O 6 Benzenesulfonamide, 4-[1-(1-oxopropyl)1H-pyrrol-3-yl]Amides of amino acids with trivial names are named systematically except in peptide nomenclature (¶ 206). Example: Me 1 CH O Benzaldehyde, 4-methyl- 6 1 CH O CH O 1,2-Benzenedicarboxaldehyde H2NCH2CONH2 Acetamide, 2-amino- (not Glycinamide) Ph CH 2 CH O Benzeneacetaldehyde Oximes of amides (amidoximes) (R-C(:NOH)NH2) are tautomeric with Nhydroxy carboximidamides (R-C(:NH)NHOH) and are indexed at imidamide names: Example: Me(C H 2 ) 4 C ( = N H )NHOH Hexanimidamide, N-hydroxy- Chalcogen analogs of aldehydes are given “-thial,” “-selenal,” “-carbothioaldehyde,” etc., names. In the presence of more highly ranked compound classes (¶ 106) or more preferred aldehydes, the -CHO group is expressed by formyl (if it does not form part of an acyclic carbon chain) or by a terminal oxo radical. For thio aldehydes, the equivalent radicals are (thioxomethyl) and a terminal thioxo radical. Examples: 172. Nitriles (RC≡N) are indexed at names derived from “-carboxylic” and “-oic” acid names by use of “-carbonitrile” and “-nitrile” suffixes, respectively. H CO CH 2 CO 2 H Propanoic acid, 3-oxo- 41 (C H 2 ) 2 C H O Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Benzenepropanal, 3-formyl(principle: largest heading parent) O = ¶ 174 C − PH 2 Methanone, phenylphosphino- CHO CN CHS T eC H (C H 2 ) 2 C H S Benzonitrile, 2-(thioxomethyl)- N CO N Methanone, 1-piperidinyl-1H-pyrrol-1-yl- Butanethial, 4-telluroxoE tCO SiH 2 O H 1-Propanone, 1-(hydroxysilyl)Methanethione, phenylphosphinothioyl- Substitution of the aldehydic hydrogen atom is not permitted. Examples: H 2 P( S) CSPh MeC ( = N O H )N O O Ethanone, 1-nitroso-, oxime (not Acetonitrosolic acid) Methanone, nitrophenyl(not Benzaldehyde, α-nitro-) C−NO2 174. Ketones, RC(:O)R′, and their chalcogen analogs are named by use of the characteristic suffixes -one, -thione, -selone, and -tellone. (The last two classes must be differentiated from selenones and tellurones, which contain the noncarbon groups -SeO2- and -TeO2-, respectively.) The carbonyl group may be attached to carbon or other elements with the exception of hydrogen and those that could form an acid, acid derivative, or amide name. Conjunctive names are not employed for acyclic ketones attached to ring systems; instead, the cyclic portion is expressed as a substituent of the acyclic ketone parent (in which the oxo group may occupy the 1-position). When an acyclic ketone with two cyclic substituents consists only of a single carbon atom with a chalcogen attached, the heading parents Methanone, Methanethione, Methaneselone and Methanetellone are employed. Examples: MeC O Me 1 2 3 Cyclic ketones (including those with neighboring hetero atoms) are named by appending “-one,” “-thione,” etc., suffixes to the ring names. Indicated hydrogen (required to form the ring system itself) is often chosen (where possible) to accommodate a single ketone group (¶ 135). In other cases, added hydrogen (¶ 136) is introduced at some other position of the ring system when the ketone suffix is attached. Examples: O 6 1 MeC H 2 O SiH 2 (C H 2 ) 2 CO( CH 2 ) 2 SiH 2 OCH 2 Me 1 34 7 10 11 13 MeC O C H 2 C O C H =CH 2 1 6 H 2 C =C =O Me(C H 2 ) 3 C H =C =O 6 1 MeC SeC H 2 Me 1 4 MeC O C H 2 C SC H 2 Me 1 6 P hC O (C H 2 ) 4 Me = 4 3-Cyclohexen-1-one 1 8a O 4 Ph 4H-1-Benzopyran-4-one, 2-phenyl(not flavone) 5 O 1 6 S 4 2-Propanone (not Acetone) 4H-Thiopyran-4-one, 2,3-dihydro(not 2H-Thiopyran-4(3H)-one) O S 3,11-Dioxa-4,10-disilatridecan-7-one 5-Hexene-2,4-dione (not 1-Hexene3,5-dione) Ethenone (not Ketene) 1-Hexen-1-one 2-Butaneselone 2-Hexanone, 4-thioxo- (not 2,4Hexanedione, 4-thio-) 8 5 7a 1 3 1H-Indene-1,3(2H)-dithione S 4 1 S NH O 3 4-Thiazolidinone O 7a H N 1 3 O 4 1H-Indole-5,6-dione, 2,3-dihydro(the two oxo substituents can be added as a pair without hydrogen being added elsewhere to the ring system) O C H 2 C H 2 COMe 1 O 9a 1 2-Butanone, 4-cyclohexyl10a 9 10 4a 1-Hexanone, 1-phenyl- (not Hexanal, 1-phenyl-) Methanone, cyclohexylideneMethanone, diphenyl- (not Benzophenone) 5 1,9,10(2H)-Anthracenetrione, 3,4dihydro- (the added hydrogen is cited in the lowest-numbered available position) O C =O Ph2CO In the presence of higher functions or more preferred ketones, oxo, thioxo, selenoxo, and telluroxo radicals, are used. The = CO group, when not part of an acyclic chain or a ring, is expressed as carbonyl; the chalcogen analogs (carbonothioyl, carbonoselenoyl, and carbonotelluroyl) are used when they are not part of a chain, and when, in addition, they are either bonded to a single atom or used as multiplicative radicals. The trivially named radicals benzoyl, for (oxophenylmethyl), and acetyl, for (1-oxoethyl), are used when appropriate. Examples: M e CO CH 2 CO Br 6 1 N 1′ N 6′ P hC O — — COPh Methanone, 1,1′-[2,2′-bipyridine]5,5′-diylbis[1-phenyl- (a multiplicative name (¶ 125)) Butanoyl bromide, 3-oxo(not Acetyl bromide, acetyl-) CO E t N —COCO — N M e CO 1-Propanone, 1-(4-acetylphenyl)- 1,2-Ethanedione, 1,2-di-2-pyridinylS CO 2 H 2H-Thiopyran-3-carboxylic acid, 3,4-dihydro-4-thioxo- A cN = N N H Ethanone, 1-(1-triazen-1-yl)- S ¶ 174 HCOCH2COCO2H 4 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Butanoic acid, 2,4-dioxo- (not Propanoic acid, 3-formyl-2-oxo-) Hydrazinecarboxylic acid, 2-(cyclopropylcarbonyl)6 42 CH =CH CH 2 O H OH 1 Phenol, 2-(3-hydroxy-1-propen-1-yl)(not 2-Propen-1-ol, 3-(2hydroxyphenyl)-) Phenol, 2-[(9-hydroxynonyl)oxy](principle: a cyclic parent is preferred (¶ 138)) Ethanol, 2-mercapto- C O N H N H CO 2 H 4 1 O ( CH 2 ) 9 O H OH N —CS — CN Benzonitrile, 3-(2-pyridinylthioxomethyl)- (not Benzonitrile, 3-(2pyridinylcarbonothioyl)-) H SCH 2 CH 2 O H 2 1 S =C CO2H Cyclopentanecarboxylic acid, 3carbonothioyl- Hydroxy derivatives of thiophene, selenophene, and tellurophene are indexed at Thiophene-ol, etc., (the final “e” of the parents being left unelided to avoid confusion with chalcogen analogs of Phenol). The locant is placed immediately before the suffix. Example: 1 1 8a N 4 N C H 2 COCH 2 COPh 4 1 5 O 1,3-Butanedione, 4-(4-oxo-3(4H)quinazolinyl)-1-phenyl- (principle: maximum number of the principal chemical functional group (¶ 138)) HTe 5 S Thiophene-3-ol, 5-tellurylOH 175. Alcohols (and phenols) and their chalcogen analogs (thiols, selenols, and tellurols) are expressed by the suffixes -ol, -thiol, -selenol, and -tellurol, attached to a carbon or silicon atom of a molecular skeleton name. The only trivial name employed in CA indexes for a compound of this class is Phenol (for Benzenol). Phenols as a class are treated precisely like alcohols, the choice of index name for a compond containing alcoholic and phenolic groups depending on the usual rules (¶ 138). Alcoholic groups and their analogs are expressed as hydroxy, mercapto, selenyl, and telluryl prefixes on more preferred heading parents. Examples: E tO H Hydroxy, mercapto, selenyl, and telluryl groups attached to hetero atoms other than silicon are always expressed as prefixes (unless they form part of an acid functional parent compound (¶ 130)). “Esters” of such groups are also expressed as prefixes. Examples: H 2 N N H SH Hydrazine, mercaptoBorinic acid, B,B-dimethyl- M e 2 BO H 8a OH N 1 Ethanol (not Ethyl alcohol) 5 3-Quinolinethiol, 1,2-dihydro-1hydroxySH 4 H 2 C =C H C H 2 O H 3 1 2-Propen-1-ol (not Allyl alcohol) 2-Propanol (not Isopropyl alcohol) 5-Hexene-3-thiol 6 MeC H (O H )Me 3 2 1 H O− O P = OH 2-Phosphorinol, 1,2-dihydro-1hydroxy-, 1-oxide H 2 C =C H C H 2 C H (S H) CH 2 Me 6 3 2 1 MeSiH 2 O H Silanol, 1-methyl1-Butanetellurol 1 NOAc Acetic acid, 1-piperidinyl ester (not Piperidine, 1-(acetyloxy)-) Me(C H 2 ) 2 C H 2 T eH 4 1 SSO 2 Ph 1 10a − 24 C H 2 -(C H 2 ) 11 -S-C H 2 - CH 2 - O- CH 2 - CH 2 - O- CH 2 - CH 2 - O- CH 2 - CH 2 - O H 12 11 10 9 8 7 6 5 4 3 2 1 9 As 10 3,6,9-Trioxa-12-thiatetracosan-1-ol 6 O 5 4 Benzenesulfonothioic acid, S-10Hphenoxarin-10-yl ester (not 10H-Phenoxarsine, 10-[(phenylsulfonyl)thio]-) P hS eH OH 8a 1 Benzeneselenol O 1-Naphthalenol (not 1-Naphthol) 4 7a 1 3 5 4 N O CO CH 2 CO 2 H O Propanedioic acid, 1-(1,3-dihydro-1,3-dioxo-2H-isoindol2-yl) ester (not Propanoic acid, 3-[(1,3-dihydro-1,3-dioxo-2Hisoindol-2-yl)oxy]-3-oxo-) — — SH SH C H 3 -C H -C H -C H 3 4 3 2 1 2,3-Butanedithiol 176. Amines are always named as primary amines, RNH2, or their N-derivatives, by attaching the suffix “-amine” to the name of a molecular skeleton, cyclic or acyclic. Attachment may be at a carbon or hetero atom. Trivial names, e.g., Aniline, and radicofunctional names, e.g., Methylamine, are not used. Examples: MeNH2 H O -SiH 2 -S iH 2 -O H OH 1 6 1,2-Disilanediol Methanamine (not Methylamine) 2-Propanamine (not Isopropylamine) 3-Buten-2-amine Plumbanamine 1,3-Benzenediol OH M e CH ( N H 2 ) M e 1 2 3 6 H 2 C=CH CH ( N H 2 ) M e 1 CH2OH OH Benzenemethanol, 2-hydroxy(not Phenol, 2-(hydroxymethyl)-) (principle: largest parent) 4 2 1 H 3 Pb N H 2 43 H2PPHNH2 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Diphosphinamine Benzenamine (not Aniline) M e ( CH 2 ) 7 N H 2 NH2 H 3 SiN H Sn H 3 ¶ 177 Silanamine, N-stannyl- (principle: preferred hetero atom) Cyclohexanamine, N-octyl- (principle: a cyclic parent is preferred) NH 2 P hN H 2 1 6 7 Bicyclo[2.2.1]hept-5-en-2-amine 6 1 NH 2 NH 4 H 2 N B iH N H 2 1 Bismuthinediamine 1,3,2-Dioxarsolan-2-amine 1,2,4-Benzenetriamine, N 2 -(3,5-diaminophenyl)- (principle: lowest locants for principal groups) H2N Me2NONMe2 NH 2 O 5 2 A sN H 2 Methanamine, N,N ′ -oxybis[Nmethyl- (principle: multiplication) O3 H N 1 5 NH2 1H-Pyrrol-2-amine MeNH NH NH NHMe H2NCH2CH2NH2 2 1 1,2-Ethanediamine (not Ethylenediamine) 1,2-Propanediamine 1,2-Benzenediamine (not 1,2-Phenylenediamine) Benzeneethanamine, α-methyl5-Pyrimidinemethanamine 1,4-Benzenediamine, N1,N 4 -bis[4-(methylamino)phenyl](principle: centrality) Replacement names are employed for acyclic secondary and tertiary amines provided that the “-amine” suffix of the “aza” name expresses at least the same number of such groups as the conventional name and that other requirements (¶ 127), e.g., the presence of a minimum of four hetero units in the molecular skeleton, are satisfied. Examples: E tN H CH 2 CH 2 N H [ ( CH 2 ) 2 N H ] 3 CH 2 CH 2 N H E t N1 1 3 13 14 N14 H 2 N C H 2 C H (N H 2 )M e 1 2 3 6 1 NH2 NH2 P hC H 2 C H MeN H 2 β α 1 6 N N3 3,6,9,12-Tetraazatetradecane-1,14diamine, N1,N 14-diethylCH 3 - N H - CH 2 - CH 2 - N H - CH 2 - CH 2 - N H - CH 2 - CH 2 - N H - CH 2 - CH 2 - NH -C H 3 N1 1 2 N2 H2NCH2 When higher functions (¶ 106) or more preferred amine parents are present, the prefix “amino” is employed. Examples: 1,2-Propanediamine, 3-(4-aminophenyl)- (principle: maximum number of the principal group) Silanamine, 1-(5-aminopentyl)(principle: hetero atom parent preferred) Benzenemethanamine, 4-amino(principle: largest heading parent) NH 2 Me CH 2 CH 2 H2N CH 2 CH(NH 2 )CH 2 NH 2 H 2 N (C H 2 ) 5 SiH 2 N H 2 1,2-Ethanediamine, N1-[2-(methylamino)ethyl]-N 2-[2-[[2- (methylamino)ethyl]amino]ethyl](not 3,6,9-Triazaundecane-1,11diamine, N1,N 11-dimethyl-; this organic replacement name expresses only three hetero units) (not 2,5,8,11,14-Pentaazapentadecane; this name does not express the amino groups as a substituent suffix) Schiff bases (anils, azomethine compounds) contain the -N=C- grouping and are therefore both amines and imines. They are indexed as amines in the absence of higher functions. Example: Ph N =CH Ph 6 H 2N 1 α CH 2 NH 2 NH 2 Me NH 2 Benzenamine, N-(phenylmethylene)- Me Me Benzenamine, 2,6-bis[(2-amino3,5-dimethylphenyl)methyl](principle: centrality) Secondary and tertiary amines, RR′NH and RR′R′′N, are named as derivatives of primary amines by application of the usual criteria (¶ 138). Examples: MeC H 2 N H C H 2 Me 2 1 N N-Hydroxy amines are named as such, not as hydroxylamine derivatives. Amine oxides are named by citation of the additive term “N-oxide” in the modification. Examples: Ph N H O H E tN ( O ) E t 2 Benzenamine, N-hydroxyEthanamine, N,N-diethyl-, N-oxide Ethanamine, N-ethyl- (not Diethylamine) 2-Propanamine, N,N-bis(1methylethyl)- (not Triisopropylamine) (Me 2 C H ) 3 N 177. Imines are ranked as the lowest compound class named by use of a functional suffix. The “-imine” suffix is attached to a cyclic or acyclic molecular skeleton (at a carbon or hetero atom). Indicated and added hydrogen (¶¶ 135, 136) for cyclic imines are assigned as for the analogous ketones (¶ 174). N-Alkyl, N-aryl, etc., imines are indexed as amines (¶ 176). Conjunctive nomenclature is used for imines when the molecular skeleton to which a single function is attached is itself connected to a ring system by a single bond. Examples: M e CH = N H 2 1 N Ethanimine (not Ethylideimine) 2-Propanimine Phosphinimine 2,4-Cyclopentadien-1-imine O NH O 2-Furanamine, N-2-furanyl- M e C( = N H ) M e 1 2 3 H 2 N -C H 2 -C H 2 -C H 2 - NH- CH 2 - CH 2 - CH 2 - NH 2 N3 3 2 1 N1 HP=NH 1-(35 NH 1 1,3-Propanediamine, N aminopropyl)- ¶ 177 1 6 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 4H-Pyran-4-imine, tetrahydro- (not 2H-Pyran-4(3H)-imine, dihydro-) 44 O NH HN=C=NH In the presence of any other chemical function expressible as a suffix, imines are described by substituent prefixes. The =NH group is named imino; the =C=NH group is expressed as carbonimidoyl in a multiplying radical or when attached to a single atom; the -CH=NH group is named (iminomethyl) (not formimidoyl) unless the methyl group is part of an acyclic carbon chain. Examples: Ph C( = N H ) SO 2 N H 2 Methanediimine (not Carbodiimide) 2-Propanamine, N,N ′ -methanetetraylbis- (not Methanediimine, N,N ′ -bis(1-methylethyl)-) Ethanimine, N-chloro-, N-oxide 2(1H)-Pyridinimine, 1-ethyl- Benzenesulfonamide, 3-(iminophenylmethyl)- Me 2 C H N = C = N C H M e 2 H N = CH CH 2 CN 3 2 1 Propanenitrile, 3-iminoCH O MeC H = N (O )C l 2 1 N OHC C( = N H ) C( = N H ) 6 Et N 1 NH 1 Benzaldehyde, 3,3′-(1,4-phenylenedicarbonimidoyl)bisNH S 3 NH 8 9 10a 10 9a 1 7a O 9,10-Anthracenediimine 4 1,3-Benzoxathiol-4-ol, 2-imino- 4a 5 OH NH P h 2 C = N SS N = C P h 2 Benzenemethanimine, N,N ′ -dithiobis[α-phenyl- (principle: multiplication of a conjunctive name) E tC( = N H ) OH Phenol, 3-(1-iminopropyl)- 45 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 D. COMPOUND CLASSES ¶ 179 Introduction Anhydrides Anions Antimony and Bismuth compounds Boron compounds Carbonic acid and relatives Cations Esters Ester-anhydrides Free radicals Halogen and Halogenoid compounds Hydrazides ¶ 178 179 180 181 182 183 184 185 186 187 188 189 Hydrazones Imides Molecular addition compounds Nitrogen compounds Organometallic compounds Oximes Oxygen compounds Phosphorus and Arsenic compounds Salts Silicon, Germanium, Tin, and Lead compounds Sulfur, Selenium, and Tellurium compounds Zwitterionic compounds ¶ 190 191 192 193 194 195 196 197 198 199 200 201 178. Introduction. Previous sections have dealt with general principles and with the naming of specific compounds by combination of a molecular skeleton name with a suffix which describes the principal chemical function. The present section discusses nonfunctional compound classes (those that fall below imines in order of precedence (¶ 106)), and classes of compounds such as esters, free radicals, ions, addition compounds, oxo acids, and carbonic acid relatives, which are named by application of principles already discussed. The order is alphabetic by class. 179. Anhydrides of acid groups, at least one of which is expressed as a functional suffix (“-oic acid,” “-carboxylic acid,” “-sulfonic acid,” etc.), are indexed, if cyclic, at heterocycle names and, if acyclic, either at “a” names (¶ 127) or at acid heading parents with the term “anhydride” in the modification. (Acyclic anhydrides of certain mononuclear “oxo” acids, e.g., Carbonic acid, Phosphonic acid, are indexed at such headings as Dicarbonic acid, Triphosphonic acid.) Replacement (“a”) names are used for acyclic anhydrides when the suffix expresses no lower functionality than the heading parent of the regular substitutive name and the other requirements (¶ 127), e.g., that the molecular skeleton contain at least four hetero units, are satisfied. Example: H O 2 C C H 2 C O O SO 2 CH 2 SO 2 OCOCH 2 CO 2 H 1 3 45 7 8 11 Anhydrides of monobasic organic acids with polybasic acids are indexed at the name of the preferred acid. The terms “di,” etc., are used to indicate the number of molecules of water lost in anhydride formation. Locants are cited for polybasic organic acids or when the parent is multiplied. A ratio is cited for anhydrides of an unmultiplied monobasic acid with an unmultiplied mononuclear polybasic acid and for anhydrides of two different unmultiplied polybasic mononuclear acids. Examples: O O O CH 3 − C − O − C − CH 2 − C − O H = = = 3 Propanedioic acid, 1-anhydride with acetic acid CH 3 2 1 CH 3 − SO 2 − O − SO 2 − CH − CH 2 − CH 2 − SO H − 1,3-Butanedisulfonic acid, 3-anhydride with methanesulfonic acid (not “3-monoanhydride with...”) = = O O 4,8-Dioxa-5,7-dithiaundecanedioic acid, 3,9-dioxo-, 5,5,7,7-tetraoxide Symmetrical anhydrides of monobasic organic acids are indexed at the acid heading parent with the term “anhydride” in the modification. Locants are used when the parent is multiplied. Unsymmetrical anhydrides of monobasic acids, at least one of which is organic, are indexed at the name of the preferred acid (¶¶ 167, 138) with an “anhydride with” phrase in the modification. Anhydrides of Hydrazinecarboxylic acid and related compounds are given special treatment (see the final example below). Examples: O O C H 3 − C H 2 − C − O − C − CH 2 − CH 3 = = O = Cl = CH 3 − CH 2 − C − O − Β− O − B − O − C − CH 2 − CH 3 CH 3 − CH 2 − C − O O = O 1 O − C − CH 2 − CH 3 O = = O − C−O−P−OH OH Benzoic acid, anhydride with phosphoric acid (1:1) O − − Propanoic acid, 1,1′,1′′,1′′′-tetraanhydride with boric acid (H4B2O5) = O = Propanoic acid, 1,1′-anhydride (Locants are used because the parent is multiplied.) Benzoic acid, 4-chloro-, 1,1′-anhydride Benzoic acid, anhydride with acetic acid (The parent is not multiplied so there are no locants.) Acetic acid, anhydride with benzenesulfonic acid Acetic acid, anhydride with nitrous acid Cl − CH 2 − C − O − C − CH 2 − O − CH 2 − C − O − C − CH 2 − Cl 2 2′ 1′ = = O O O = Cl 4 1 C−O−C Acetic acid, 2,2 ′ -oxybis-, 1,1′ - dianhydride with 2-chloroacetic acid (principle: centrality (¶ 138)) O H O O C − CH 2 − CH 2 − C − O − CN = O O Butanedioic acid, 1-anhydride with cyanic acid = == = O = = C−O−C−C H 3 O O S−O−C−C H 3 O = = O = HOOC 4 1 C − O − SO 2 − O H 1,4-Benzenedicarboxylic acid, 1-anhydride with sulfuric acid Acyclic anhydrides of different polybasic acids require locants. Examples: CH3−C−ONO O = HOOC O O C − O − C − O − CH 3 = 4 1 O = O = CO O H C−O−C−O−C = = Benzoic acid, anhydride with methyl hydrogen carbonate (the ester name is given in its uninverted form (¶ 185); not Benzoic acid, anhydride with methoxyformic acid) Dicarbonic dihydrazide, 2-methyl(see also ¶ 183) 1,4-Benzenedicarboxylic acid, 1,1′-dianhydride with carbonic acid O O O O H 2 N N H C − O − C N H NHCH 3 = H O − SO 2 − O − C − CH 2 − C − O − SO 2 − O H Propanedioic acid, 1,3-dianhydride with sulfuric acid ¶ 179 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 COOH O O C−O−C = = 12 3 4 46 COOH 1′ 2′ CH 3 CH 3 O = O = O = O = 1,2-Benzenedicarboxylic acid, 4-methyl-, 1,2′-anhydride (formerly bimol. 1,2′-monoanhydride) H 3 C − N − ( CH 2 ) 4 − B − O − Β− O − B − ( CH 2 ) 4 − N − CH 3 − − CH 3 O H ( CH 2) 4 H 3 C − N − CH 3 − − − CH 3 − OH O = O = H O − C − ( C H 2 ) 4 − C − O − C −( CH 2 ) 4 − C − O − C −( CH 2 ) 4 − C − O Η Boronic acid, B-[4-(dimethylamino)butyl]-, B,B′:B′,B′′-, dianhydride (formerly Boronic acid, [4(dimethylamino)butyl]trimol. dianhydride) Hexanedioic acid, 1,1′:6′,1′′-dianhydride (formerly trimol. dianhydride) When the acid group which has undergone anhydride formation would have been expressed (in its unmodified form) as a substituent of the preferred heading parent, the anhydride is likewise expressed as a (more complex) substituent of the same parent. Anhydride formation of an acid group expressed as a substituent in an “anhydride with” phrase is treated similarly. Examples: O C H 3 −C−O−S O 2 COO H Unsymmetrical anhydrides of “oxo” acids in general are indexed by use of “anhydride with” phrases at the preferred acid component heading parents, but cyanic acid anhydrides with mononuclear arsenic and phosphorus acids are expressed by means of “cyanatido” replacement affixes or by the class term “cyanate.” Examples: CH 3 − P − O − CN − O OH = = O Phosphonocyanatidic acid, P-methyl- Benzoic acid, 4-[(acetyloxy)sulfonyl]- CH 3 − P − O − CN H3C − Phosphinic cyanate, P,P-dimethyl- Chalcogen analogs of acyclic anhydrides are indexed like anhydrides. When the oxygen atom connecting the acid residues has been replaced, the terms “anhydrosulfide,” “anhydroselenide,” and “anhydrotelluride” are used, and the sulfur, selenium, or tellurium is indicated in the names of both acid components. Examples: S S C−O−C = H−P−S−P−H − − OH SH = HC−O−O−C−ΟH O O = = = Benzenecarbothioic acid, 1,1′-anhydride (not “anhydrosulfide”) The peroxy analogs of this kind of “oxo” acid are indexed (with synonym line formulas) at such headings as Thioperoxydiarsonic acid ([(HO)HAs(S)]2S2). Anhydrides of mononuclear peroxy “oxo” acids are generally named at Peroxide, Disulfide, etc. Examples: O O = O Se C H 3 − C H 2 − C − S − P − CH 2 − CH 3 = O − CH 2 − CH 3 = − MeC( = NOH)SCN Symmetrical anhydrides of the monobasic “oxo” acids Formic, Phosphinic, Arsenic, Phosphinous, and Arsinous acids (and their substituted derivatives) are indexed by citation of the simple term “anhydride” in the modification. Symmetrical anhydrides of the dibasic “oxo” acids Phosphonic, Arsonic, Phosphonous, and Arsonous acids and their substituted derivatives are indexed at Di-, Tri-, etc., acid headings. Example: MeA s(O H )O A s(O H) Me Anhydrides of boron acids are named as anhydrides. Examples: PhB MeO B MePh = O O O C − O − C − C H 2 − SO 2 − O − C − CH 3 = O = Benzoic acid, anhydride with 2-[(acetyloxy)sulfonyl]acetic acid Anhydrosulfides of “oxo” acids are generally named analogously by use of “anhydrosulfide” terms. Other chalcogens are treated similarly. When sulfur, etc., replaces oxygen in Diphosphonic acid and similar compounds, the nondetachable prefixes “Thio,” etc., are employed. The number of sulfur atoms is not indicated in the name; instead, a synonym line formula is always cited. Example: O S O C − Se − C − CH 3 = = = Thiodiphosphonic acid ((HO)HP(O)SHP(S)SH) S O 2 − Τ e − SO 2 = = Peroxide, carboxy formyl Benzenesulfonotelluroic acid, 1,1′-anhydrotelluride H−P−S−S−S−ΟH − OH − OH Disulfide, hydroxyphosphinyl sulfo Cyclic anhydrides, anhydrosulfides, etc., are indexed like other heterocyclic compounds. Examples: Benzenecarboselenoic acid, anhydroselenide with ethaneselenoic acid O 7a 1 2O 3 1,3-Isobenzofurandione (not 1,2Benzenedicarboxylic acid, cyclic anhydride) O 4 Propanethioic acid, anhydrosulfide with O-ethyl hydrogen P-ethylphosphonoselenothioate 1 O2S 9a 9b 3 O2 SO 2 4 Naphth[1,2-c][1,2,5]oxadithiole, 1,1,3,3-tetraoxide (not 1,2Naphthalenedisulfonic acid, cyclic anhydride) Ethanimidothioic acid, N-hydroxy-, anhydrosulfide with thiocyanic acid 6 5 O 7a 1 3 4 S2 Benzo[c]thiophene-1,3-dione O Diarsonous acid, dimethyl- Borinic acid, B-methyl-B-phenyl-, B,B′-anhydride (not Borane, oxybis[methylphenyl-) 180. Anions. Index names for anions are required as sole entries when anions themselves are being studied, and as additional entries in the indexing of salts (¶ 198). Anions are often expressed differently as modification terms at cationic heading parents. Anions from unsubstituted Ethyne, Arsine, Phosphine, Stibine, Silane (Si4− only), and Hydrazine are named Acetylide, Arsenide, Phosphide, Antimonide, Silicide, and Hydrazide. Synonym line formulas are used, e.g., Acetylide (C22− ), except for Hydrazide (which is H2NNH− ) and Silicide, and for Arsenide, Phosphide, and Antimonide when all hydrogens have been lost. Anions derived from compounds with names based on substitutive parent compounds (¶ 130) other than those just described are named at the heading parent for the neutral compound with a modification term such as “ion(1−),” “ion(2−),” or (if indefinite) “ion (neg).” Anions from esters of “oxo” acids are named similarly. 47 Examples: 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 181 − HC 1,3-Cyclopentadiene, ion(1−) Radical ions are named at the neutral compound heading with “radical ion” terms in the modification. Examples: •− Naphthalene, radical ion(1−) MeC H 2 C H 2 O − 3 1 1-Propanol, ion(1−) (not Propoxide) 6 O• 1 − O O2N 6 1 NO2 Phenol, 2,4,6-trinitro-, ion(1−) 2,5-Cyclohexadiene-1,4-dione, radical ion(1−) O− NO2 6 1 CO2− CO2− 1,2-Benzenedicarboxylic acid, ion(2−) Me 2 A s − Arsine, dimethyl-, ion(1−) Phosphonic acid, P-ethyl-, ion(1−) Sulfuric acid, monophenyl ester, ion(1−) 1,2-Ethanedisulfonic acid, 1-methyl ester, ion(1−) EtP(O)(OH)O− At cationic index headings, e.g., Ethanaminium (see ¶¶ 184, 198), anions are expressed by “-ide” or “-ate” terms, as described below, or by “salt with” phrases. The “salt with” phrase is followed by a ratio, e.g., (1:1). Modification terms for unsubstituted carbanions from acyclic and monocyclic hydrocarbons are derived by adding “-ide” to the hydrocarbon name after elision of the final “e,” e.g., “benzenide,” “cyclopentadienide.” Unsubstituted acids expressed as principal groups (e.g., carboxylic and sulfonic acids) afford anions which are named by “-ate” terms in the modification, e.g., “acetate,” “1,2-benzenedicarboxylate.” Phosphonic acid, Carbamic acid, and other substitutive functional parent acids, whether substituted or not, also provide anions which are named in modifications by means of “-ate” terms, e.g., “phosphonate,” “dimethylcarbamate.” Similar terms are used for anions from partial esters of polybasic “oxo” acids. Examples: O CH 3 − P − O − − O − CH 3 P hO SO 3 − P-methyl O-methylphosphonate = MeO 3 SC H 2 C H 2 SO 3 − 1 2 O CH 3 − O − C − S − CO 2 − O-methyl carbonothioate = Certain resonance-stabilized anions and cations containing hetero atoms are indexed by CA at names corresponding to preferred canonical structures. In the same manner as the analogous tautomeric compounds (¶ 122), anions are normalized, i.e., recognized as equivalent, by machine programs, regardless of how the structures are shown in the original documents. Each ion is assigned a single CAS Registry Number and a unique CA index name. Resonance-stabilized anions of the general formula M=Q−Z− −M−Q=Z 1-methyl 1,2-benzenedicarboxylate CO 2 M e O CH 3 − O − P − O − − O− = P-methyl phosphate in which Q = C, N, S, P, Sb, As, Se, Te, Br, Cl, or I, and M and Z represent any combination of trivalent N and/or bivalent O, S, Se, or Te atoms are normalized in this way. The formula is analogous to that for normalized tautomeric compounds (¶ 122), with a negative charge replacing the hydrogen atom, and the requirements described for them apply equally to normalized anions. The names are derived by the same structural rules, and are identical except for addition of the index modification term “ion(1−)”. Examples: − E tC − NH = EtC = NH − O O− Anions from the unsubstituted alcohols and phenols Methanol, Ethanol, 1-Propanol, 1-Butanol, and Phenol are named by “-oxide” terms, e.g., “propoxide,” “phenoxide”. Loss of hydrogen from the mercapto group of unsubstituted Benzenethiol is expressed as “benzenethiolate”. In all other cases, anion names at cation headings are replaced by “salt with” phrases; it is to be understood that, in a complete salt name, a ratio would always be added when known. Examples: MeO O− salt with 4-methoxyphenol (not “4-methoxyphenoxide”) Propanamide, ion(1−) 3 NOT Propanimidic acid, ion(1−) 1 7a Ph N H — salt with benzenamine NO2 4 N 7a −1 N − N O2N 3 N Cl 4 O− NO2 Cl salt with 2,4,6-trinitrophenol (not “picrate”) 1H-Benzimidazole, 6-chloro-, ion(1−) NOT 1H-Benzimidazole, 5-chloro-, ion(1−) Negative ions from tautomeric pyrazole and tropolone systems are not normalized by the CAS Registry System; their preferred structures and names are based on nomenclature rules, such as low numbering for principal functional groups, low numbering for substituents, etc. 1 2 Me N − Me N2 CN N −N1 5 CN 1H-Pyrazole-3-carbonitrile, 5-methyl-, ion(1−) NOT 1H-Pyrazole-5-carbonitrile, 3-methyl-, ion(1−) 181. Antimony and Bismuth compounds, are conveniently discussed together because of the close similarity in the indexing treatment of their derivatives. Antimony and bismuth are metals (¶ 215), and their salts are named as such, not as cyclic or acyclic molecular skeletons. (Prior to CA Volume 95 (see ¶ 101), antimony was classed as a nonmetal for indexing purposes; now, it and bismuth are treated alike.) Hydrides of trivalent antimony and bismuth are named Stibine and Bismuthine, respectively; polymolecular saturated and unsaturated hydride chains have names such as Distibine, Distibene, Tribismuthine. The mononuclear oxide heading parents Stibine oxide and Bismuthine oxide are employed, as are also the analogous names for the sulfides, etc., and imides. In heterocyclic compounds the valency is understood to be three unless an abnormal valency can be expressed in the name (¶ 158). Examples: E t 3 Bi Bismuthine, triethyl- ¶ 181 E tSbC l 2 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Stibine, dichloroethylBismuthine, iododiphenylMeB(Me)CH 2 O(CH 2 ) 2 OCH 2 B(Me)Me 1 2 4 7 9 10 48 P h 2 B iI Acyclic carbon chains containing boron atoms are given “a” names if the requirements (¶ 127) are met. Example: 4,7-Dioxa-2,9-diboradecane, 2,9-dimethyl- (F 3 C ) 2 S bS bMe 2 2 1 Distibine, 1,1-dimethyl-2,2-bis(trifluoromethyl)Distibene, 1,2-diphenylStibine oxide, hydroxydiphenylStibinamine, 1-oxide Bismuthine imide, 1-ethyl-Nmethyl1H-Stibole P hS b=SbP h P h 2 Sb(O )O H Heterocyclic boron compounds and their derivatives are named by the usual procedures (¶ 146). Intramolecular coordination bonds between boron atoms and other hetero atoms are ignored in naming; thus, a zwitterionic ring bond between boron and phosphorus in the last example below is disregarded, and the monocyclic system is named. (A monocycle entirely dependent on such a bond is named as an acyclic compound.) Examples: H B H 2 S b(O )N H 2 1 N 5 1 1H-Borole 6 H N 1 4 2 E tB iH 2 =N Me 1 N HB HN 5 BH NH 3 1 7a Borazine H Sb 5 1 B H O 2 1 7a B( CH 2 ) 2 CN O 3 S 2 B iH S3 1,3,2-Benzodithiabismole 4 8 1 1,3,2-Benzodioxaborole-2-propanenitrile 4 Heterocyclic antimony and bismuth compounds without functional suffixes are ranked in accordance with the seniority of ring systems (¶ 138). Nonfunctional acyclic antimony substitutive parent compounds follow arsenic compounds in order of precedence (¶ 106) and are followed in turn by bismuth and then boron parents. Within each class the order is determined by the number of hetero atoms, then unsaturation, size and additive hetero atoms, as illustrated by the following descending order of antimony compounds: Tristibine, Distibene, Distibine, Stibine oxide, Stibine sulfide, Stibine imide, Stibine. In the presence of more preferred compound classes, the following substituent prefixes are employed. (The substituent prefixes stiboso (−SbO), stibo (−SbO2), stibinico (=Sb(O)OH), and stibono (−Sb(O)(OH)2) were used prior to CA Volume 95 (see ¶ 101).) Substituent Prefix −SbH2 =SbH ≡Sb −Sb=Sb− Examples: HO2CCH2S SbI 2 P B 5 1,5-Phosphaborocine Boron molecular skeletons fall between nonfunctional bismuth and silicon compounds in the order of precedence of compound classes (¶ 106). Within the boron class, the descending order is carbapolyboranes, hetero polyboranes, polyboranes, heterocyclic boron compounds, and finally Borane. When more preferred groups or molecular skeletons are present, boron substituent prefixes (¶ 161) are used. Examples: Me3B H 2 Sb BH 2 Borane, trimethylStibine, borylBoranamine, N,1,1-trimethyl(principle: heteroatom molecular skeleton preferred) 3′ Substituent Prefix −BiH2 =BiH ≡Bi bismuthino bismuthylene bismuthylidyne stibino stibylene stibylidyne 1,2-distibenediyl M e 2 BN H M e 1N 3 1 1′ N BPh N H Aziridine, 1,1′-(phenylborylene)bis- Cl B H Acetic acid, 2-[[4-(diiodostibino)phenyl]thio]- H2B H Diborane(6), 1-chloro- P hN =B iI N Benzenamine, N-(iodobismuthylene)- Trihydroxy and hydroxy oxo derivatives of Stibine, Bismuthine, Stibine oxide, Bismuthine oxide and their chalcogen analogs are given binary oxide, hydroxide, etc., names (with synonym line formulas) such as Antimony hydroxide (Sb(OH)3), Bismuth hydroxide (Bi(OH)3), Antimony hydroxide oxide (Sb(OH)O) and Bismuth hydroxide oxide (Bi(OH)O). (Antimonic acid headings were used prior to CA Volume 95 (see ¶ 101).) Halo, alkoxy, and aryloxy derivatives of Stibine, Bismuthine and their oxides are so named; amino derivatives are named at Stibinamine, Stibinediamine, Bismuthinamine, etc. Examples: MeO S bC l 2 When the position of substituent suffixes or prefixes cannot be related to the accepted numbering of polyboranes and hetero polyboranes (as illustrated in the Ring Systems Handbook and current Chemical Substance Index), no numerical locants are used, but capital italic letters may be cited to denote substitution on a “hetero” atom in a hetero polyborane. Examples: B10H9 AcO B10C2Me2H10 1,2-Dicarbadodecaborane(12), B-(acetyloxy)Dicarbadodecaborane(12), C,C ′ dimethyl- Stibine, dichloromethoxyStibinamine, 1,1-dihydroxy-, 1-oxide Substitution of bridging hydrogen of a polyborane or hetero polyborane is indicated by the prefix “µ” (mu); when necessary, the locants of the boronatom bridgeheads are cited. Examples: H H2B N Ph H H2B 4 H H H B NH2 1 2 BH 2 (H O ) 2 Sb(O )N H 2 BH 2 Diborane(6), 1,2-[µ-(phenylamino)]- Arsenic compounds. See Phosphorus and Arsenic compounds (¶ 197). 182. Boron compounds. For the naming of neutral boron hydrides and replacement (“a”) analogs (hetero polyboranes) see ¶¶ 159, 160. Except for hydroxyl groups attached to boron (¶ 175), principal groups on such hydrides are expressed as suffixes in the regular way, and conjunctive names are adopted with those known to have closed polyhedral structures; e.g., Diborane(4)1,1,2,2-tetramine and 1,2-Dicarbadodecaborane(12)-1,2-diethanol. Tetraborane(10), 1,2-µ-amino- BH 3 H 49 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 H N Br 2 B Me−N H BBr 2 N−H B Br 2 M e Me ¶ 183 Cyclic derivatives of polyboranes (other than Diborane(4)) and hetero polyboranes formed by replacement of non-bridging hydrogen atoms by bivalent radicals are named by citing such radicals as substituents. Examples: Diborane(6), 1,1-(1,4-butanediyl)1 Borazine, 2,2,4,4,6,6-hexabromo1,2,3,4,5,6-hexahydro-1,3,5trimethyl- H2B 2 H O 1 2 B H 1,2-Dicarbadodecaborane(12), 1,2-[oxybis(methylene)]- B 10 H 10 Hydroxy derivatives of Borane have acid names as follows: B (O H ) 3 H B (O H ) 2 H 2 B (O H ) Boric acid (H3BO3) Boronic acid Borinic acid Boronic and borinic acids have replaceable hydrogen atoms attached to boron and are used as substitutive parent compounds. Their esters, anhydrides and salts are named in the usual way, but their acid halides, amides and hydrazides are named as Borane, Boranamine, and Hydrazine derivatives, respectively. Chalcogen analogs are named by use of afffixes thio, seleno, and telluro. Hydroxy derivatives of Diborane(4), are now indexed at that index heading parent. Examples: MeB (O Me)O E t Ionic boron compounds are indexed by coordination nomenclature (see ¶ 215) at such names as Borate(2−), decahydrodeca- (for [B10H10]2−), and Boron(1+), diamminedihydro- (for [BH2(NH3)2]1+). Acidic polyboranes and hetero polyboranes are named as complex acids (¶ 215); e.g., Borate(2−), decahydrodeca-, hydrogen (1:2) (not Decaborane(12)). Prior to the Eleventh Collective Index period, the special term “borata” denoted a tetrahedral borate anion attached to carbon atoms in a heterocyclic ring system. Now, compounds of this type are named by coordination nomenclature at such index headings as Borate(1−). 183. Carbonic acid and relatives, with a few trivially named exceptions, are indexed by the principles of replacement nomenclature for functions (¶ 129), based on the names Carbonic acid (for (HO)2C=O) and Formic acid (for HCO2H). Trivial names employed in CA indexes are: Formyl halides and halogenides (except the cyanide, which is indexed at Acetonitrile, 2-oxo-), Formamide, Formaldehyde, Hydrocyanic acid, Urea, Guanidine, Cyanic acid, Thiocyanic acid, Selenocyanic acid, and Tellurocyanic acid. These trivially named compounds are ranked with the appropriate class (acid, amide, etc.) as Carbonic acid derivatives, which fall below derivatives of acids named as principal groups (carboxylic, sulfonic, etc.) and above inorganic “oxo” acids (Hypochlorous acid, Phosphonic acid, etc.) (see ¶ 106). Examples: O H − C − N CO O H − C − O CN HCΟΝHMe = = Formyl isocyanate Formic acid, anhydride with cyanic acid Formamide, N-methyl- Boronic acid, B-methyl-, ethyl methyl ester Borinic acid, B-methyl-B-phenylBoronodithioic acid, B-phenylAcetic acid anhydride with B,B-dimethylborinic acid Hydrazine, 1,1′-(phenylborylene)bisDiborane(4), 1,1,2,2-tetrahydroxy(prior to CA Volume 95 the name Hypoboric acid was used) Boranetriamine P hB MeO H P hB (SH ) 2 A cO B Me 2 Analogs (imidic, hydrazonic, peroxy, chalcogen) of Formic acid, Formamide, etc., are named systematically as methanoic acid analogs, but are ranked as compounds related to Formic acid. Examples: O H−C−O−OH S = = Methaneperoxoic acid Methane(dithioic) acid (not Formic acid, dithio-) Methanethioamide (not Formamide, thio-) Methanimidoyl isocyanate Methane(dithioic) acid, anhydrosulfide with thiocyanic acid Formic acid, 1-(thiocarboxy)(not Methanethioic acid, carboxy-) P hB (N H N H 2 ) 2 (H O ) 2 B B (O H ) 2 H − C − SH H CSN H 2 B (N H 2 ) 3 H C( =N H ) N CO Boric acid (H3BO3) is not a substitutive parent. Esters and anhydrides are indexed as functional derivatives; hydrazides are indexed at Hydrazine. Examples: (H O ) 2 B O P r (H 2 N N H ) 3 B H CS 2 CN Boric acid (H3BO3), monopropyl ester Hydrazine, 1,1′,1′′-borylidynetris- S H O − C − CO 2 H = Addition compounds of neutral boranes are named as molecular coordination compounds (see ¶ 215). (Prior to CA Volume 95 (see ¶ 101), they were indexed at the component names (¶ 192).) Example: B (N Me 3 )H 3 Boron, (N,N-dimethylmethanamine)trihydro(T-4)- (preferred index name) (formerly indexed at Methanamine, N,N-dimethyl-, compd. with borane (1:1), and at Borane, compd. with N,N-dimethylmethanamine (1:1)) Replacement of the nuclear hydrogen atom in formic acid compounds by radicals derived from molecular skeletons leads to carboxylic acids, carbothioamides, etc., expressed as suffixes on the skeleton names. Formaldehyde analogs have systematic names based on Methane, e.g., Methanimine (for CH2=NH) and Methanethial (for CH2=S). (Methanethione (¶ 174) is employed only as the index heading parent for thio ketones with two cyclic substituents and for cyclic thio ketenes.) Replacement of hydrogen in formaldehyde by carbon skeletons leads to larger aldehydes and to ketones; they and their analogs are named by the usual principles of substitutive nomenclature (¶¶ 173, 174). Replacement by nitrogen, halogen, etc., leads to compounds which are often named as Formic or Carbonic acid derivatives. Examples: N Oligomeric boranamines which are linear or unspecified are indexed at the monomer name with “dimer,” “trimer,” etc., in the modification. Cyclic dimers are named as µ-derivatives of Diborane(6). Monocyclic trimers, tetramers, etc., are given ring names in which the abnormal valencies of hetero atoms are expressed (see ¶ 158). Examples: Me 2 N F2B BF2 N Me 2 3-Pyridinecarboxaldehyde CH O Ph 2 CO Ph C( =N H ) M e H CO N H 2 H 2 N CO Cl Cl 2 C=N H Methanone, diphenylBenzenemethanimine, α-methylFormamide Carbamic chloride Carbonimidic dichloride Diborane(6), bis[µ-(dimethyl amino)]tetrafluoro- ¶ 183 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 50 Carbonic acid analogs in which oxygen is replaced by halogen, halogenoid, chalcogen, or nitrogen atoms or groups (¶ 129) (except cyano or a single hydrazino) are given functional replacement names. The replacement of one hydroxyl by amino leads formally to Carbonamidic acid, H2NC(O)OH, but it and its analogs are named at the approved abbreviated forms Carbamic acid, Carbamothioic acid, etc. Examples: (H O ) 2 C =N H Carbonimidic acid (the tautomeric Carbamic acid is preferred in indexing unless both acid hydrogen atoms have been replaced.) Carbamimidic acid (not Carbonamidimidic acid) (Urea is preferred in indexing in the absence of a covalent acid derivative.) Carbonochloridic acid Carbonocyanidic acid Carbonodiperoxoic acid Carbamo(dithioperox)imidic acid Carbonothioic dichloride Carbonic bromide chloride H 2 N C (=N H )O H C lC O 2 H NCCO2H (H O O ) 2 C O H 2 N C (=N H )S S H Cl2CS C lC O B r Carbonic acid and its relatives are placed in the order of precedence of compound classes just below acids expressed as suffixes attached to molecular skeleton names, e.g., sulfonic acids (¶ 106). Within this subclass of acids, they are ranked by the following criteria, applied successively until a decision is reached: (a) number of acid groups; (b) number of nuclear carbon atoms; (c) precedence of atoms directly attached to nuclear carbon atoms (see Table I, ¶ 128); (d) number of most preferred hetero atoms directly attached to nuclear carbon atoms; (e) order of priority of other atoms or groups attached to nuclear carbon atoms. A partial list in descending order is: Peroxydicarbonic acid, Dicarbonic acid, Imidodicarbonic acid, Carbonoperoxoic acid, Carbonic acid, Carbonimidic acid, Carbonochloridic acid, Carbamic acid, Formic acid, Cyanic acid, and Thiocyanic acid. (Chalcogen analogs of each acid immediately follow it in descending order of increasing replacement of oxygen by sulfur, selenium, and tellurium.) Acid chlorides, amides, etc., are ranked within their own classes in a similar order. Carbamic acid derivatives with cyclic substituents are not assigned conjunctive names. In the presence of higher functions, including any acid expressed as a suffix, the carbamic acid residue is indicated by a (carboxyamino) radical. Its replacement analogs are named in the usual manner. Its hydrazides are indexed at Hydrazinecarboxamide. Examples: N H CO 2 H Carbamic acid, N-2-naphthalenyl(not 2-Naphthalenecarbamic acid) Carbamic acid, N ,N ′ -1,4phenylenebis(not Carbamic acid, 1,4phenylenebis- (see ¶ 118)) Carbamodithioic acid, N,N dimethylCarbamimidic acid, N-propyl-, ethyl ester H O 2 CN H N H CO 2 H Carbonic diamide is named Urea, and its chalcogen analogs are indexed at Thiourea (not Urea, thio-), etc. The monohydrazide of carbonic acid is Hydrazinecarboxylic acid, but the dihydrazide is named Carbonic dihydrazide. The monocyanide of Carbonic acid is Acetonitrile, 2-oxo-; the dicyanide is Propanedinitrile, 2-oxo-; the trivial name Guanidine is employed for Carbonimidic diamide. Examples: MeN H C (=N H )N H Et N′ N′′ N M e 2 N CS 2 H Pr N H C( =N H ) O E t Guanidine, N-ethyl-N ′ -methylHO3S N H CO 2 H Carbonic acid linear polyanhydrides are named at Dicarbonic acid, Tricarbonic acid, etc. Carbonimidic, carbonoperoxoic, and carbonimidoperoxoic acid anhydrides are named in the same manner. When all the anhydride oxygens have been replaced by -OO- or -NH- groups, nondetachable “peroxy-” and “imino-” prefixes are cited ahead of the name along with multiplicative prefixes. Chalcogen analogs are treated similarly, except that synonym line formulas form part of the name, and multiplicative prefixes are not cited. When both acid groups have been replaced by amide or acid halide functions, appropriate names are derived, but when only one hydroxyl group has been replaced, or different functions are present, choice of a simpler parent is made. Longer chains can often be indexed by replacement (“a”) nomenclature (¶ 127). Examples: O = S = 1 Benzenesulfonic acid, 4-(carboxyamino)- Cyanic acid and its chalcogen analogs are treated as mononuclear “oxo” acids; their esters and anhydrides are named in the usual way. Isocyanic acid and its analogs are not used in general index nomenclature; their esters and anhydrides are named like halogen compounds. The acids themselves, and their salts, are indexed at Cyanic acid, Thiocyanic acid, etc. The amide, H2NCN, is named Cyanamide. Examples: M e O CN O = O = HO−C−O−C−OH NH = NH = NH = H O − C − O − C − O − C − OH O = 2 Dicarbonic acid Tricarbonimidic acid Dicarbonodiperoxoic acid Cyanic acid, methyl ester Ethanethioic acid, anhydrosulfide with thiocyanic acid CO 2 H H 3 CC( O ) SCN O = N CO H O − O − C − O − C − O − OH Benzoic acid, 4-cyanatoBenzene, isocyanato- (not Isocyanic acid, phenyl ester) 2-Propenoyl isocyanate Cyanamide, N-phenyl- (not Benzenecarbamonitrile) HO2COOCO2H NH = NH = S = NH = Peroxydicarbonic acid Ph N CO H O − C − N H − C − N H − C − OH Diimidotricarbonimidic acid H 2 C=CH CO N CO HO−C−S−S−C−OH O = O = O = Thioperoxydicarbonic acid ([(HO)C(S)]2S2) Ph N H CN Cl−C−O−C−Cl Dicarbonic dichloride Imidodicarbonic bromide chloride Imidodicarbonic dihydrazide Carbamic acid, N-(chlorocarbonyl)O = 4 5 6 Cl−C−NH−C−Br Numerical and italic letter locants are used with carbonic acid relatives to place substituents. Locants are employed with monosubstituted Guanidine and Carbamimidic acid. Examples: M e N H CO N H 2 N N′ H 2 N N H C O N H C O NHNH 2 Urea, N-methylThiourea, N,N ′ -dimethylHydrazinecarboximidothioic acid, ethyl ester C lC O N H C O 2 H O = O = 3 M e N H CSN H M e N N′ O = 7 8 O = 9 N H 2 − C − N H − C − N H − C − NH − C − NH − C − NH 2 H 2 N N H C( = N H ) SE t 2,4,6,8-Tetraazanonanediamide, 3,5,7-trioxo- 51 H2NNHCONHNH2 21 1′ 2′ Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Carbonic dihydrazide Guanidine MeC≡ N+Me Pr 3 N + ( CH 2 ) 2 N + Pr 3 ¶ 184 H 2 N C ( = N H )N H 2 N N′′ N′ N′′ N′′′ 1,2-Ethanediaminium, N1,N1,N1,N 2,N 2,N 2hexapropyl- (principle: maximum number of the preferred substituent suffix) Methanaminium, N-ethylidyne- NH = N 1 2 NH = 3 N′ N′′′ H2N−C−NH−C−NH2 N′′ N′′′′ Imidodicarbonimidic diamide NH = N 1 2 NH = 3 4 NH = N H 2 − C − N H − C − N H − C − NH 2 5 N′ Diimidotricarbonimidic diamide Quaternary ammonium cations not included in the heading parent are expressed as substituted ammonio, +NH3−, iminio, +NH2=, and nitrilio, +NH≡, radicals. Example: CH 3 + CH 3 + CH 3 + 184. Cations, including carbonium ions (which possess an electron-deficient, tricoordinate carbon atom), “ium” ions (defined for index nomenclature purposes as resulting from addition of a proton to a saturated carbon atom or of one covalent substituent other than hydrogen to a fully substituted hetero atom), and radical cations related to these two classes are described here. (For salts of which they are components, see ¶ 198.) When a proton is added to a hetero atom, the resulting compound is named as a salt (if the anion is known) or by such modification phrases as “conjugate acid” or “conjugate monoacid” at the neutral component followed by the appropriate ratio. Examples: MeO H • H F (not [Me OH 2 ] + F − ) N • H+ H 3 C − N − ( CH 2 ) 6 − N − ( CH 2 ) 3 − N − ( CH 2 ) 6 − N H 2 − − − CH 3 CH 3 CH 3 Hydrofluoric acid, compd. with methanol (1:1) Pyridine, conjugate acid (1:1) Aminium and diaminium names may be derived from amines named by replacement (“a”) nomenclature. In addition, cationic centers in the “a” name of a molecular skeleton may be expressed, if such a name is permitted (see ¶ 127), by use of the “azonia” replacement prefix. Example: CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 |+ |+ |+ |+ |+ |+ CH3−CH2−N−(CH2)6−N−(CH2)6−N−(CH2)6−N−(CH2)6−N−(|CH2)6−N−CH2−CH3 N′| N| 7| 14 | 21 | 28 | CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 − − − 1,6-Hexanediaminium, N1-[3-[(6aminohexyl)dimethylammonio]propyl]-N1,N1,N6,N 6,N 6-pentamethyl- (principle: largest heading parent) Carbon cations formally derived by addition of a proton to a saturated carbon atom are named at the molecular skeleton name by use of a modification term such as “protonated”. Example: MeC H 4 + 7,14,21,28-Tetraazoniatetratriacontane-1,34-diaminium, N1,N34diethyl-N1,N1,N34,N34,7,7,14,14,21,21,28,28-dodecamethylIminium names are employed when the quaternary nitrogen atom is attached to one or more bivalent radicals derived from a molecular skeleton, and analogous monovalent radicals are absent. The names are derived from those of the preferred imines (¶ 177). Example: Ph 2 C=N + =CPh 2 Ethane, protonated (1:1) Orthodox carbonium compounds are named from the hydrocarbon (or other parent) radical by addition of “-ium.” Examples: MeC H 2 + Me 2 C H + Ethylium Ethylium, 1-methyl- (not 2Propylium Ethylium, 1-oxo- (not Acetylium) Methylium, cyclopropyloxo- (not Cyclopropylcarbonylium) Benzenemethaniminium, N(diphenylmethylene)-α-phenyl- MeC O + 2 1 Diazonium compounds contain the −N2+ group attached to a substitutive parent compound. When such a parent is a molecular skeleton, the suffix “-diazonium” is employed; otherwise Diazonium is the heading parent. The corresponding substituent prefix is “diazonio.” Examples: M e CO CH ( N 2 + ) CO M e 1 3 4 5 CO+ H + O O 3-Pentanediazonium, 2,4-dioxoBenzenediazonium, 4-chloro1,4-Benzenebis(diazonium) Diazonium, (methylamino)- Cl 1,3-Dioxan-5-ylium +N 2 N2+ N2+ 2+ Naphthalenediylium, dihydroMeNHN2+ Acyclic nitrogen cations derived from amines attached to parent molecular skeletons are named by converting the preferred “-amine” name (¶ 176) to “-aminium” and expressing the remaining quaternizing groups as substituent prefixes. Examples: Me 4 N + Cl +N 2 NMe N2+ Benzenediazonium, 3-chloro-4[(4-diazoniophenyl)methylamino]- Methanaminium, N,N,N-trimethylMethanaminium, N-methyl-N-oxoCH 3 CH 3 + Me 2 N + O Cations from acyclic nitrogen molecular skeletons are named in a similar manner by use of the “-ium” suffix. Lowest locants are given to cationic centers when a choice is necessary. Examples: Ph N + M e 2 N H 2 − CH=N C − CH 3 CH 3 2-Propanaminium, N,2-dimethyl-N-(phenylmethylene)(principle: largest amine parent) − − Hydrazinium, 1,1-dimethyl-1phenylTriazanium, 2,2-dimethyl2-Triazenium, 1,1,1,3-tetramethylHydrazinium, 1,1,1,2,2,2-hexamethyl- H2NN+Me2NH2 12 3 M e N =N N + M e 3 O (C H 2 ) 2 N + Et 2 Me 2-Furanethanaminium, N,N-diethyl-N-methyl- (from a conjunctively-named amine) 3 21 Me3N+N+Me3 ¶ 184 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 52 Acyclic cations from nonnitrogenous hetero atoms are indexed at Phosphonium, Arsonium, Stibonium, Bismuthonium, Oxonium, Sulfonium, Iodonium, etc. The corresponding substituent prefixes are phosphonio, arsonio, etc. Diphosphine, H2P-PH2, affords Diphosphinium. Examples: Me 3 P + (C H 2 ) 2 P + Me 3 Phosphonium, 1,1′-(1,2-ethanediyl)bis[1,1,1trimethyl- (analogous compounds with one or more noncarbon attachments to phosphorus are indexed at Phosphorus(1+) (see ¶ 215)) Diphosphinium, 2,2-dichloro1,1,1-trimethylArsonium, tetramethylSulfonium, trimethyl- (the corresponding S-oxide is named Sulfoxonium, trimethyl-) Iodonium, diphenyl- (the corresponding I-oxide is named Iodonium, diphenyl-, I-oxide) In all the examples above, the charge of the cationic atom was derived from an additional covalent substituent at a ring hetero atom already saturated to the covalency limit. Similar names are used (for rings other than those with “a” names) when the covalency limit is exceeded within the ring system itself, no “external” substitution being involved. The “-ium” name is derived from the uncharged heterocycle, indicated hydrogen, if present, being removed. If indicated hydrogen is needed for the cationic system, it is added at the lowest available nonangular position. The trivial names Furylium, Pyrylium, Thiopyrylium (and their benzo analogs), and Xanthylium (from Xanthene) are used. When other hetero atoms are present in the ring system, a locant before the “-ium” suffix defines the position of the cationic center. Examples: 9a 1 C l 2 P P + Me 3 Me 4 As+ +N 5 6 Quinolizinium Me 3 S + Ph2I+ MeO — +O 1 Pyrylium, 4-methoxy- (from 2Hor 4H-Pyran) MeO 9a 9b OMe 1 Cyclic cations from rings with “a” names are named by replacing the aza, oxa, thia, etc., terms by the cationic prefixes azonia, oxonia, thionia, etc. They are cited in the same order as the corresponding neutral terms (Table I ¶ 128); when the same element is present in neutral and cationic forms, alphabetic order of the terms is followed, but the cationic center is preferred for lowest locants if a choice is available. Examples: 8 9 6 10 1 2 6 1 5 + I 5 Dibenziodolium, 1,9-dimethoxy4 O + O3 Me 1,3-Dioxol-1-ium, 2-methyl- +NEt 9 1O HN 5 1 5-Aza-2-azoniabicyclo[4.2.2]decane, 2,2-diethylMe2N 6 N + S 5 1 1O a 4 NMe2 Phenothiazin-5-ium, 3,7-bis(dimethylamino)- P 6 O 8 + 7O 4 O 2 P Me 1 2,6,7-Trioxa-1-phospha-4-phosphoniabicyclo[2.2.2]octane, 4-methyl- 7 + 8 SMe 5 9 1 8-Thioniabicyclo[3.2.1]octane, 8-methyl- O 5 4 Me Me Cationic heterocyclic monospiro compounds, other than those from “a”named rings, have the “-ium” term placed in the name in accordance with the nature of the component rings. When the cationic hetero atoms are in nonspiro positions, the “-ium” suffix is appended to the appropriate component. If the spiro and cationic centers coincide, or if both component rings contain such a center, the “-ium” is attached only to the second component (if the components are different). For “a”-named components, “azonia,” “oxonia,” etc., terms are used as appropriate; in addition, an “-ium” suffix is attached to the second component if the spiro atom is cationic and the second component does not have an “a” name. Examples: Me MeN + 3 5′ 1 1-Oxa-4-azoniaspiro[4.4]nonane, 2,2,4,4-tetramethyl- S 7a 4 1′ N+ Me 2 9 1 Spiro[benzothiazolium-4(5H),1′cyclopentane], 6,7-dihydro-2,3dimethyl- + P 5 5-Phosphoniaspiro[4.4]nonane 8′a 1′ 2′ 1 Cationic monocyclic and fused ring systems, other than those with “a” names, are indexed at heading parents derived from the heterocycle name by addition of an “-ium” suffix. Lowest locants are preferred for indicated hydrogen, e.g., 1H (never 3H)-Benzimidazolium; a cationic center is numbered lower than a neutral hetero atom of the same element if a choice is available. Examples: + Me N 1 O 5 2 +N M e 2 6′ 5′ 4′ Spiro[1,3-dioxolane-2,6′(2′H)isoquinolinium], 2′,2′-dimethyl- O 3 4′ 8a 5′ 6′ N 2N + 6 Pyridinium, 1,3-dimethylMe 9 1O 1 5 4 1′ 9′a Spiro[isoquinoline-2(1H), 2′-[2H] pyrido[1,2-a]pyrazinium] N 5 9a 9b 1 1O a Br 6 +N Me 4 Br Phenazinium, 3,7-dibromo-5methyl- (not Phenazinium, 2,8dibromo-10-methyl-) 6 4′ 5 5′ P+ 4 6′ Spirobi[5H-dibenzophospholium] 6 Me +N 2 1 4 1′ 9′b 9′a Piperazinium, 1,1,4,4-tetramethyl1′ 1 + 4′a 4′b +N Me 2 + Et O 5 1 Me2N 3 6 9′ 8′ Spiro[3-azoniabicyclo[3.1.0]hexane6,9′-[9H]fluorene], 3,3-dimethyl- Furanium, 1-ethyltetrahydro- 53 1 7 8 9 5 3 N 3′ 5′ Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 + ¶ 184 O 1′ Spiro[3-azoniabicyclo[3.2.2]nonane-3,3′(2H)-oxazolium] Dispiro compounds with other than “a”-named components and containing two cationic spiro atoms have the “ium” suffix appended to the terminal, i.e., the first and third, component names. Several classes of resonance-stabilized cations containing nitrogen atoms are either normalized by the CAS Registry System or treated as though they were; i.e., to avoid scattering of information in CA indexes, each such cation, regardless of how its structure is drawn, is assigned a unique CAS Registry Number and unique CA Chemical Substance Index name (cf. ¶¶ 122, 180). A normalized cation is any cyclic cation with the substructure — — − N = C(or N) − N − + Cationic prefixes are used when more preferred compound classes (¶ 106) are present, or when different cations, or additional occurrences of the same cation, cannot be included in the heading parent. Heteroacyclic cationic prefixes are based on “-onio” radicals such as ammonio and iminio (for singly and doubly bound nitrogen, respectively), diazonio, sulfonio, phosphonio, and iodonio. Cyclic cationic radicals from rings, not named by “a” nomenclature, containing a single hetero atom at which the free valency is located are named by changing the “-ium” ending of the cation name to “-io”; e.g., pyridinio, 2Hpyranio, phenanthridinio. In all other cases, heteroacyclic and heterocyclic cationic prefixes are derived from the cation name by adding “-yl,” “-diyl,” etc., to the “-ium” suffix with locants (low-numbered if there is a choice) to indicate the points of attachment. Examples: Me +N 1 − N − C(or N) = N − + 6 (1-methylpyridinium-2-yl) − − − − R R′ R R′ Me + N 1 4 where (a) the terminal N’s are in the same ring or adjacent rings (but not at a ring junction) and (b) the bonds to R and R′ are not part of the ring. Examples: 7a 6 (1,4-dimethylpiperazinium-1,4-diyl) Me N 1 + 4 3 Me N + Me 9 N + NPh 3 7a NPh 1 N 10 5 10a 1 4 1H-Benzimidazolium, 1methyl-3-phenyl(principle: positive charge on the CIP-preferred nitrogen) Me Me 2 1 6 5 NOT 1H-Benzimidazolium, 3methyl-1-phenyl- (5-methyl-10H-phenothiazinium10-yl) 4 6 +S Me + Me2NN=NN Me2− 43 21 (1,1,4,4-tetramethyl-2-tetrazenium1-yl) Me Me 8 1 6 5 3 + N O N 3 N 7 + N 2 N7 9 6 8 + N 1 piperidinium-1-ylidene 4 9 N Ph O N 4 N Ph 8 1 1H-Purinium, 2,7-dihydro-1,7-dimethyl2-oxo-9-phenyl(principle: positive charge on the CIP-preferred nitrogen) NOT 1H-Purinium, 2,9-dihydro-1,7-dimethyl2-oxo-9-phenyl- N+ 9 1-azoniabicyclo[3.3.1]non-1-yl 5 For resonance-stabilized cations that are not normalized, the unique CA Chemical Substance Index name is derived by regular nomenclature rules (see ¶ 138). CH 3 CH 2 CH 3 CH 2 Carbon cationic prefixes are named by addition of “-yl” to the cation name. Locants are cited (except for methane prefixes) for both the cationic center and the point of attachment, with lowest locants for the latter. Examples: + H2C — + MeC H — methyliumyl 1-ethylium-1-yl −+ − N = CH − N− − CH 3 CH 3 CH 3 CH 2 CH 3 CH 2 + − − N − CH = N− − CH 3 CH 3 Ethanaminium, N-[(dimethylamino)methylene]-N-ethyl(principle: preferred index parent) 1 Et 8a NOT Methanaminium, N-[(diethylamino)methylene]N-methyl- O 612 + (tetrahydro-4H-pyran4-ylium-4-yl) N + 8a Et N 1 + 4 1 + 8a 3 (octahydro-8a(1H)azulenylium-1-yl) N 4 N 4 Imidazo[1,2-a]pyridinium, 1-ethyl(principle: the neutral ring, quaternized by substitution, is preferred) NOT 1H-Imidazo[1,2-a]pyridin4-ium, 1-ethyl- When at least one canonical form of a resonance-stabilized cation represents a hydrogen atom as being attached to a positively charged nitrogen atom, it is named as a neutral compound with an index modification term such as “conjugate acid” or (if the anion is known) as a salt such as “hydrochloride” followed by the appropriate ratios. Example: Me +N Cationic compounds are ranked in the following descending order of precedence of elements: C, N, P, As, Sb, Bi, O, S, Se, Te, F, Cl, Br, I. When more than one cationic center is present, the general rules of substitutive nomenclature (¶ 138) are applied, the cationic centers being considered as principal chemical groups for this purpose. Examples: Cycloheptatrienylium, (1-methylpyridinium-4-yl)- (principle: carbon cation preferred) + MeN + NHPh • Cl − CO 2 Me Me N + NHPh • Cl − CO 2 Me Me N NPh • HCl CO 2 Me M e 3 N + ( CH 2 ) 3 S + M e 2 (The hydrochloride salt is the preferred structure.) 1-Propanaminium, 3-(dimethylsulfonio)-N,N,N-trimethyl(principle: nitrogen cation preferred) ¶ 184 Me N + CH 2 Me +N 4 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Pyrazinium, 1,4-dimethyl-2-[(1methylquinolinium-6-yl) methyl]- (principle: maximum number of cationic centers) 54 +N Me 6 6 + (CH 2 ) 2 NMe 3 +N 1 Pyridinium, 1-[2-(trimethylammonio)ethyl]- (principle: ring parent preferred) Me N + (C H 2 ) 2 Me Me MeN 3 1 S + 7a 4 Benzothiazolium, 3-methyl-2[2-(1,3,3-trimethyl-3Hindolium-2-yl)ethyl](principle: preferred ring) Cationic compounds of indefinite structure are named by use of alternative locants if possible, e.g., Quinazolinium, 1(or 3)-methyl-, iodide (1:1); otherwise as molecular addition compounds of the neutral compounds with a term such as “compd. with iodomethane (1:1)” (not “monomethiodide”) in the modification. Cationic free radicals from carbonium ions are named like the carbon cationic prefixes (above); e.g., Methyliumyl; 4-Cyclohexylium-1-yl. When the free radical and cationic centers are separated, the “-yl” suffix is preceded by a locant, if known. When the free radical and cationic center are in different parent molecular skeletons, the free radical supplies the heading parent. Examples: • are modified for esters. The chemical functionality (¶ 106) of certain very common acids (“Class I” acids) is disregarded for the purpose of naming their esters, unless the “alcoholic” component is also very common, and the entry is made instead at the uncommon alcohol, despite its lower functionality. The “Class I” acids comprise: Acetic acid; Benzenesulfonic acid; Benzenesulfonic acid, 4-methyl-; Benzoic acid and its monoamino, mononitro, and dinitro derivatives; Boric acid (H3BO3); Carbamic acid; Carbamic acid, N-methyl-; Carbamic acid, N-phenyl-; Carbonic acid; Formic acid; Methanesulfonic acid; Nitric acid; Phosphoric acid; Phosphorodithioic acid; Phosphorothioic acid; Phosphorous acid; Propanoic acid; Sulfuric acid; and Sulfurous acid. All other acids, including isotopically labeled forms of “Class I” acids, belong to “Class II.” Esters of “Class I” monobasic acids with “Class II” alcohols and thiols are indexed at the latter. Esters of “Class I” acids with “Class I” alcohols and thiols are indexed at the acids. “Class I” alcohols are: Benzeneethanol; Benzenemethanol; 1-Butanol; 1-Butanol, 2-ethyl-; 2-Butanol; Cyclohexanol; 1Decanol; 1-Dodecanol; Ethanol; Ethanol, 2-(diethylamino)-; Ethanol, 2(dimethylamino)-; Ethenol; 1-Heptanol; 1-Hexanol; 1-Hexanol, 2-ethyl-; Methanol; 1-Nonanol; 1-Octadecanol; 1-Octanol; 1-Pentanol; Phenol and its monochloro, monomethyl, and mononitro derivatives; 1-Propanol; 1-Propanol, 2-methyl-; 2-Propanol; 2-Propanol, 2-methyl-; and 2-Propen-1-ol. The list of “Class I” thiols is completely analogous to the “Class I” alcohol list; the individual index names are also analogous, e.g., Benzeneethanethiol; 2Propanethiol, 2-methyl-; except that the Phenol analog is Benzenethiol. All selenols and tellurols belong to “Class II.” Esters formed from hydroxy derivatives of nitrogen, phosphorus, arsenic, antimony, bismuth, germanium, tin and lead are named as such. They are always indexed at the acid regardless of the type of acid. The acyclic nitrogen radicals used in ester names are azanyl, diazanyl, diazenyl, triazanyl, etc. Examples: A c O ( CH 2 ) 2 Ph Acetic acid, 2-phenylethyl ester Sulfuric acid, monomethyl ester (the uninverted name is methyl hydrogen sulfate) Phosphorodithioic acid, O-methyl S-phenyl ester Acetic acid, diphenylazanyl ester M e O SO 3 H Piperidinium-4-yl, 1,1-dimethylMe Ph SP( S) ( O M e ) O H O CH 3 − C − O − N Ph 2 = + N Me • N Me CH2 Me + N Me 2-Pyrrolidinyl, 2-[(1,1-dimethylpyrrolidinium-2-yl)methyl]-1-methyl- Delocalized radical cations are described at the index name of the corresponding neutral compound by the modification term “radical ion” followed by a cationic Ewens-Bassett number in parentheses. Example: • + In each of the examples above, a “Class I” acid is esterified by a “Class I” alcohol or thiol. When the acid belongs to “Class I” and the alcohol or thiol to “Class II,” the entry is found at the alcoholic component name, except when the acid is polybasic and the alcohols differ from one another, in which case the acid heading is chosen. When the ester is named at the alcohol heading a locant is always cited for the “ate” or “ite” term. This eliminates the need for the parenthetical expression “(ester)”. Examples: CH 3 SO 2 − O − CH 2 − CH 2 − Ο H 1 2 Azulene, radical ion(1+) 6 1 OAc 1,2-Ethanediol, 1-(4-methylbenzenesulfonate) 1,2-Cyclohexanediol, 1-acetate 2-benzoate 1,2-Ethanediol, 1,2-diformate (the uninverted name is 1,2-ethanediyl diformate) Cationic free radicals formally derived by loss of an electron from a hetero atom of a molecular skeleton or of an isolated chalcogen atom are named similarly (¶ 270). Example: + Me 3 N • O Bz H CO 2 CH 2 CH 2 O 2 CH 1 2 Methanamine, N,N-dimethyl-, radical ion(1+) O 2 CN H M e 185. Esters, other than cyclic esters, of principal functions are named as such for indexing purposes, usually at the acid component name. Cyclic esters are named as heterocyclic ring system derivatives. Esters of hydroxy, mercapto, carboxy, sulfo, etc., groups expressed as substituents of heading parents are expressed as compound or complex substituents, not as modification terms at the same heading parent. To be recognized as an ester in CA indexing, a C-O, C-S, C-Se, or C-Te bond must be present. Thus, ethyl cyanate and ethyl perchlorate are considered to be esters, but ethyl azide, ethyl isocyanate, and ethyl chloride are not. Examples: E tO C N O2N AcO OH 1,3-Benzenediol, 5-nitro-, 1-(N-methylcarbamate) OH NH2 [ Cl( CH 2 ) 2 O ] 3 P( O ) 1,3-Benzenediol, 4-amino-, 1-acetate Cyanic acid, ethyl ester Perchloric acid, ethyl ester Ethane, azidoEthane, isocyanatoEthane, chloro- E tO C lO 3 E tN 3 E tN C O E tC l Ethanol, 2-chloro-, 1,1′,1′′-phosphate (3:1) (all the “Class II” alcoholic components are alike here; the ratio is necessary to indicate a neutral ester of known composition; the mono- and diesters are named with “dihydrogen phosphate” and “hydrogen phosphate”, respectively in the modification) Phosphorous acid, 2-hydroxyethyl dimethyl ester (the entry is made at a “Class I” acid, not at the “Class II” alcohol 1,2-Ethanediol, because the alcoholic components are unlike) H O ( CH 2 ) 2 O P( O M e ) 2 To permit information on esterified alcohols and thiols to be more readily found in the Chemical Substance Index, the usual rules of index name selection 55 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 H O − CH 2 − CH 2 − O − SO 2 − O − CH 2 − CH 2 − O H 2 1 1′ 2′ ¶ 185 When an ester of the type illustrated immediately above has a more preferred acid residue present in the molecule, the “Class I” polybasic acid becomes a substituent. Example: = O C H 3 − O − P − O − C H 2 − COOH − O − C H 2 − C H 2 − OH 1,2-Ethanediol, 1,1′-sulfate Esters are named by replacement (“a”) nomenclature if the requirements (¶ 127) are met. Example: H O CH 2 CH 2 O SO 2 O ( CH 2 ) 2 O SO 2 O CH 2 CH 2 O SO 3 H 12 10 9 8 54 3 1 Acetic acid, 2-[[(2-hydroxyethoxy)methoxyphosphinyl]oxy]- (not Acetic acid, hydroxy-, 2-hydroxyethyl methyl phosphate) Esterified substituents of the index heading parent are expressed as substituents, not as modification phrases. Examples: A cO S O 3 Me Benzenesulfonic acid, 3-(acetyloxy)-, methyl ester (not Benzenesulfonic acid, 3-hydroxy-, methyl ester acetate) O 3,5,8,10-Tetraoxa-4,9-dithiadodecane-1,12-diol, 1-(hydrogen sulfate), 4,4,9,9-tetraoxide Multiplicative radicals in modifications are cited ahead of nonmultiplicative. Example: ( M e O ) 2 BO ( CH 2 ) 3 O B( O M e ) 2 HOOC 4′ O − C −Ο 4 1 COOH Boric acid (H3BO3), B,B′-(1,3-propanediyl) B,B,B′B′tetramethyl ester = Benzoic acid, 4,4′-[carbonylbis(oxy)]bis- (not Benzoic acid, 4-hydroxy-, carbonate (2:1)) The phrase “ester with” is usually avoided in general index nomenclature for compounds of known structure, even when the alcoholic component contains a function higher than alcohol, but it is employed when an acid which requires a line formula is cited in a modification; a ratio is included if the alcohol is monohydric and has a single occurrence, and locants are used if the alcohol is polyhydric or has multiple occurrences. Examples: ΟΗ C l − C H 2 − C H 2 − O − B − OH − 2 1 Although locants to differentiate between principal and subsidiary groups are strictly not necessary in ester modifications (because esterification of the latter is not expressed in the modification), they are nevertheless cited to preclude misinterpretation. Examples: HO3S CO 2 Ph Benzoic acid, 3-sulfo-, 1-phenyl ester Ph O 3 S Ethanol, 2-chloro, ester with boric acid (H3BO3) (1:1) ΟΗ CO 2 H Benzoic acid, 3-(phenoxysulfonyl)- OH 1 2 H O − B − O − C H 2 − C H 2 − O − B − OH 1,2-Ethanediol, 1,2-diester with boric acid (H3BO3) Esterification of an alcoholic component cited in the index modification is expressed as a substituent of the esterifying radical. Example: CH 3 Ο Ο Ο 3 H O − C H 2 − C H 2 − O − B − O − CH 2 − CH 2 − OH 2 1 1′ 2′ The word “hydrogen,” with multiplicative prefixes if necessary, is used with an “-ate” (or “-ite”) term derived from a polybasic acid cited in a modification to denote unesterified acid groups. One or more “hydrogen” terms may be replaced by radicals to denote further esterification not expressed in the heading parent. When all acid groups of a polybasic acid have been esterified, “hydrogen” cannot be cited; therefore, if the precise structure is known, a ratio is placed after the “-ate” term. If more than one such term is necessary, the complete “-ate” phrases are cited (without commas) in alphabetical order. Examples: Ο Ο H O − P − Ο − C H 2 − C H 2 − O − P − O − CH 2 − CH 2 − OH − ΟΗ 1 2 = Br = Ο = 3 C−Ο−CΗ2 O−C = − − H O − P − Ο − C H 2 − C H 2 − O − SO 2 − OH ΟΗ 1 2 H O − C H 2 − C H − C H 2 − O − SO 2 − OH 2 1 − − Ο 1 ΟΗ CH 3 − CH − C − O − CH 2 − C − CH 2 − O − C − CH 2 − C − O − CH 2 − CH 3 2 − = = = = − 1,2-Ethanediol, 1,1′-diester with boric acid (H3BO3) Propanedioic acid, 1-ethyl 3-[3-(2-methyl-1-oxopropoxy)-2-oxopropyl] ester (not Propanedioic acid, ethyl 3-hydroxy-2oxopropyl ester, 2-methylpropanoate) The choice of a preferred index name for a complex ester depends on the normal criteria (¶ 138), first on the preferred acid class (peroxoic, carboxylic, carboximidic, sulfonic, carbonic, etc.) then on the preferred heading parent and the particular occurrence of such a parent if it occurs more than once. If there are three or more occurrences, the principle of centrality is invoked; if there are only two, often the preferred name is the one appearing earliest in index sequence. Example: O O 1 4 Br = ΟΗ 1,2-Ethanediol, 1-(dihydrogen phosphate) 2-(hydroxyethyl hydrogen phosphate) (principle: maximum number of functional derivatives) Benzoic acid, 4-bromo-, 4-[[(4-bromobenzoyl)oxy]methyl]phenyl ester (not Benzoic acid, 4-bromo-, [4-[(4-bromobenzoyl)oxy]phenyl]methyl ester) When functions higher in precedence than acids are present, all esters are expressed as substituents. Example: Me N1 + Cl − 1,2-Ethanediol, 1-(dihydrogen phosphate) 2-(hydrogen sulfate) 6 CO 2 E t ΟΗ Pyridinium, 3-(ethoxycarbonyl)1-methyl-, chloride (1:1) 1,2,3-Propanetriol, 1-(hydrogen sulfate) Peroxy acid esters and their chalcogen analogs are named in the usual way, with “OO,” “OS,” “SeO,” “SS,” etc., locants used when necessary along with the usual “O,” “S,” etc., locants. − ¶ 185 Examples: = = OO Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 O O − C − ( CH 2 ) 1 6 − CH 3 = 56 C l 3 C − O − O − C − C − O − O − CCl 3 Ethanediperoxoic acid, 1,2-bis(trichloromethyl) ester CH 3 CH 3 O = CH 3 = CH 3 − ( CH 2 ) 1 6 − C − O − CH 2 − CH − CH 2 − O − C − ( CH 2 ) 1 6 − CH 3 − = − − C H 3 − C H − O − C − O − O − C − CH 2 − CH 2 − C − O − O − C − O − CH − CH 3 − − CH 3 O 1 − CH3 O CH 3 Octadecanoic acid, 1,1′,1′′-(1,2,3-propanetriyl) ester CH 2 − O − C − ( CH 2 ) 1 6 − CH 3 = CH 3 − ( CH 2 ) 7 − CH = CH − ( CH 2 ) 7 − C − O − CH − CH 2 − O − C − ( CH 2 ) 1 6 − C H 3 18 17−11 10 9 8−2 = O O = O 1 O Carbonoperoxoic acid, OOc,OO c ′-(1,1,4,4-tetramethyl1,4-butanediyl) Oc,O c ′-bis(1methylethyl) ester = O C − Ο − S − CCl 3 Benzenecarbo(thioperoxoic) acid, OS-(trichloromethyl) ester Ethanesulfeno(thioperoxoic) acid, SO-methyl ester 9-Octadecenoic acid, 2-[(1-oxooctadecyl)oxy]-1[[(1-oxooctadecyl)oxy]methyl]ethyl ester (principle: unsaturated acid preferred) Urethanes are esters of Carbamic acid and its derivatives. Xanthic acids are O-esters of Carbonodithioic acid. Examples: Ph N H CO 2 E t E tSS O Me C H 3 − C H 2 − O − C − S − S − CCl 3 = N − CH 3 Carbono(dithioperox)imidic acid, N-methyl-, O-ethyl SS-(trichloromethyl) ester Carbamic acid, N-phenyl-, ethyl ester Carbonodithioic acid, O-phenyl ester Ph O CS 2 H Esters of boric acids and their chalcogen analogs are indexed regularly, except for those of Hypoboric acid and cyclic metaboric acids, (HBO2 ) n , which are named as derivatives of the molecular skeletons. Examples: (E tO ) 2 B B (O Me) 2 1 6 Cyclic esters and lactones are indexed as heterocycles. Examples: 1 Diborane(4), 1,1-diethoxy-2,2dimethoxy- O 6 O O3 Me Me O 2 1,3-Dioxane-4,6-dione, 2,2-dimethyl(not Propanedioic acid, cyclic 1methylethylidene ester) MeO B 5 B O Me 4 O O 3 Boroxin, 2,4,6-trimethoxy1 O B O Me (B uS) 2 B O Me O Thioboric acid ((HO)(HS)2B), S,S-dibutyl O-methyl ester 5 NH 2(5H)-Furanimine (not 2-Butenimidic acid, 4-hydroxy-, γ-lactone) Esters of ortho acids and their peroxy and chalcogen analogs are indexed like ethers, sulfides, peroxides, hydroperoxides, alcohols, etc. Ortho acid names are not used as heading parents. Examples: MeC (O Me) 3 1 6 O 2 O P OEt Ethane, 1,1,1-trimethoxy- (not Orthoacetic acid, trimethyl ester) Benzene, [tris(methylthio)methyl]1 1,2-Oxaphosphorinane, 2-ethoxy-, 2-oxide (not Phosphonic acid, (4-hydroxybutyl)-, monoethyl ester, δ-lactone) P hC (SMe) 3 MeC (O E t) 2 O H MeC (O E t) 2 O O C Me 3 O−CH3 O−CH3 Ethanol, 1,1-diethoxyPeroxide, 1,1-diethoxyethyl 1,1dimethylethyl Methanesulfenic acid, trimethoxy-, methyl ester 8a O O 2H-1-Benzopyran-2-one (not Coumarin; not 2-Propenoic acid, 3-(2-hydroxyphenyl)-, δ-lactone) 5 4 − C H 3 − O − C − S − O − CH 3 − Oxides of thio esters are named not as ester derivatives but at the preferred molecular skeleton or other heading parent with sulfinyl or sulfonyl prefixes. Examples: OO H3C−O = = 1 4 S−S O − CH 3 186. Ester-anhydrides are named by combining the policies for anhydrides and esters (¶¶ 179, 185). Cyclic anhydride and cyclic ester components are named in accordance with heterocyclic nomenclature. Anhydride terms precede ester terms where this can be done unambiguously (but see the last example, below). Esters cited in modifications are named in the uninverted form unless the acid is one for which a synonym line formula is required. Examples: O 7a Benzene, 1-methoxy-4-[[(4-methoxyphenyl)sulfinyl]sulfonyl]C−S−CH3 = α O O CO 2 ( CH 2 ) 2 O 2 C 4 O 3 O N−OH N Methanone, (methylsulfinyl)phenyl-, oxime Glycerides, esters of 1,2,3-Propanetriol (glycerol), are indexed at the name of the preferred acid unless only “Class I” acids are present. Examples: O O = 1 5-Isobenzofurancarboxylic acid, 1,3-dihydro-1,3-dioxo-, 5,5′-(1,2-ethanediyl) ester − = O − C − CH 3 2 3 O 8a 1 C H 3 − C − O − C H 2 − CH − CH 2 − O − C − CH 3 S 4 N O3 1,2,3-Propanetriol, 1,2,3-triacetate 5 O 4H-3,1-Benzoxathiin-4-one, 2-(cyclohexylimino)- (not Carbonimidothioic acid, cyclohexyl-, anhydride with 2-mercaptobenzoic acid, cyclic ester) = = 2 O = O O = 57 = O Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Acetic acid, anhydride with ethyl hydrogen phosphonate CH 2 − CH 3 − O−B − O − C − CH 3 = O − C − CH 3 O = O ¶ 188 E tO − P − O A c H − The heading parent Nitroxide is employed for the free radical H2N − O •. Example: Me2N O • Nitroxide, dimethyl CH3−CH2−C−C=C CH3 = O Acetic acid, anhydride with boric acid (H3BO3) mono(1-ethyl-2methyl-3-oxo-1-penten-1-yl) ester (2:1) = C lC H 2 − C H 2 − Ο − C − CH 2 − CH 2 − C C lC H 2 − C H 2 − Ο − C − CH 2 − CH 2 − C = O = O O Free radicals from hydroxyl and hydroperoxy groups that are attached to a molecular skeleton, including (acyloxy) radicals (see below), are indexed at “oxy” and “-dioxy” heading parents with systematically named nondetachable prefixes. Chalcogen analogs are named similarly at “-thio” and “-dithio” heading parents. Examples: MeO • O Methoxy (not Oxy, methyl-) Methoxy, oxo- (not Formyloxy) Ethyldioxy, 1-oxoEthoxy, 1-oxo- (not Acetyloxy) N=NO• HC−O • O = − O Butanedioic acid, 1,1′-anhydride, 4,4′-bis(2chloroethyl) ester = CH 3 − C − Ο O • = O CH 3 − C − O • = O − = = C H 3 − Ο − C − C H 2 − CH 2 − C −Ο− C − CH 3 4 3 2 1 = O O O Cl Diazenyloxy, 2-(4-chlorophenyl)Methylthio Butanedioic acid, 1-anhydride with acetic acid, 4-methyl ester = = O O − O − CH − CH 3 − CH 3 MeS • Acyl free radicals (derived from aldehydes or acids) are named as α-oxo derivatives of the alkyl parents. Examples: CH 3 − C• CO• = O Ο − C − CH 2 − C −Ο− B − O − CH 3 Ethyl, 1-oxo- (not Acetyl) Methyl, cyclopropyloxo- (not Cyclopropylcarbonyl) Methyl, aminooxo- (not Aminocarbonyl) Propanedioic acid, 1-anhydride with boric acid (H3BO3) monomethyl mono (1-methylethyl) ester, 3-phenyl ester 187. Free radicals, highest in the order of precedence of compound classes (¶ 106) and functional groups, if present, are named as substituents. Most, but not all, free radical names coincide with the names of substituent prefixes (¶¶ 132, 133). Examples: Et • P hC H 2 • H 2 N CO • Free radicals from sulfonic and sulfinic acids are named as derivatives of alkyl and aryl sulfonyl and sulfinyl radicals and the analogous oxy radicals. Examples: CH 3 − SO 2 − O • Ethyl Methyl, phenylMethyl, 1,1′-(1,4-phenylene)bisMethylidyne, bromoEthyl, 2-ethoxy-1,2-dioxo- (not Acetyl, ethoxyoxo-) Phosphino Silylene, difluoroHydrazinyl, 1-formyl-2,2-diphenyl- (Methylsulfonyl)oxy S( O ) • Me Phenylsulfinyl, 4-methyl- •CH2 B rC • • • E tO 2 C C O • 21 CH 2 • H2P• F2Si • • P h 2 N N (C H O )• 21 The following chalcogen hydride free radicals are employed: Hydroxyl, HO•; Hydroperoxo, HOO•; Mercapto, HS•; and Selenyl, HSe•. 188. Halogen and halogenoid compounds. (See also Acid halides, ¶ 170). The halogen and halogenoid “oxo” acids are hypohalous acids, HOX (e.g., Hypochlorous acid, HOCl); halous acids, HOXO; halic acids, HOXO2; perhalic acids, HOXO3; Cyanic acid, HOCN; and Fulminic acid, HONC. Their esters and anhydrides are named in the regular way. They rank below acids, e.g., carboxylic, sulfonic, expressed as suffixes on molecular skeleton names (¶ 106), and in their presence are expressed as cyanato, (iodyloxy), (chloryloxy), etc., radicals. Examples: Ph O F Hypofluorous acid, phenyl ester Bromic acid, 3-oxobutyl ester Free radicals that might be considered as derived from Borane are indexed at Borane(1) and Borane(2). Examples: FH B • FB • • M e CO ( CH 2 ) 2 O Br O 2 O CN Borane(2), fluoro- (not Boryl, fluoro-) Borane(1), fluoro- (not Boron fluoride (BF)) Cl Me Cyanic acid, 3-methylphenyl ester Benzoic acid, 4-chloro-, anhydride with hypoiodous acid (not Benzoyl hypoiodite, 4-chloro-) Propanethioic acid, anhydrosulfide with thiohypochlorous acid (not Propanoyl thiohypochlorite) Acetic acid, 2-cyanato- CO 2 I Free radicals from ammonia, amides, or amines are named as Amidogen, H2N•, Imidogen, HN:, and their derivatives. CH 3 − CH 2 − C − S − Cl = O F2N• Amidogen, difluoro- (not Nitrogen fluoride (NF2)) Imidogen, (carboxyphenylmethyl)- P hC H (C O 2 H )N • • N CO CH 2 CO 2 H ¶ 188 O 2 C lO CO 2 H Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Benzoic acid, 4-(chloryloxy)- 58 The groups −X, −XO, −XO2, −XO3, −NC, −NCO, −N3, and their chalcogen analogs, e.g., −XSe; −NCS, are normally expressed as substituent prefixes when attached to a molecular skeleton; the radicals chloro, chlorosyl, chloryl, perchloryl, isocyano, isocyanato, isothiocyanato, azido, etc., are used (see the Illustrative List of Substituent Prefixes in Section H (¶ 294)). Examples: CHCl3 P hIO 2 NC N 1 190. Hydrazones of ketone and aldehyde principal groups are expressed by hydrazone terms in the index modification, except for hydrazones of carbonyl groups of acids, acid halides, and amides; these are usually indexed as hydrazonic acids (¶ 169) and their halides and amides. Azines are indexed as “-ylidene” hydrazones; osazones as dihydrazones (of adjacent carbonyl groups); and cyclic hydrazones as heterocycles. In the presence of compound classes more preferred than the aldehyde or ketone bearing the hydrazone, a hydrazono substituent is cited. Examples: Me2C=NNH2 Methane, trichloro- (not Chloroform) Benzene, iodyl- 2-Propanone, hydrazone N H N = CH ( CH 2 ) 2 Ph Ph ( CH 2 ) 2 CH = N N H 6 Piperidine, 1-isocyano- Benzenepropanal, 1,1′ -[2,2′ -(1,4-phenylene)dihydrazone] H2 H2 C−C H2C C−C H2 H2 − CH 3 Me 2 Si(N C O ) 2 Silane, diisocyanatodimethyl- (not Isocyanic acid, dimethylsilylene ester) C = N − N = C − ( CH 2 ) 4 − CH 3 Groups such as −I(OH)2, −ClBr2, are not expressed by (dihydroxyiodo) and (dibromochloro) radicals; instead, coordination nomenclature (¶ 215) based on the central halogen atom is employed. Example: P hI(O H ) 2 Iodine, dihydroxyphenylPh N H N = CH SCH 2 CO 2 H Cyclohexanone, 2-(1-methylhexylidene)hydrazone (not 2-Heptanone, azine with cyclohexanone) (principle: ring preferred to chain) Acetic acid, 2-[[(2-phenylhydrazinylidene)methyl]thio]- (not Acetic acid, mercapto-, formate, phenylhydrazone) 1,2-Ethanedione, 1,2-diphenyl-, 1,2-bis(2-methylhydrazone) Dibenzo[c,g][1,2,5,6]tetrazocine (not 3,5-Cyclohexadiene-1,2-dione, bimol. cyclic azine) 189. Hydrazides of principal acid groups are expressed by hydrazide terms in the index modification except for (a) sulfenic acid hydrazides, R−S−NHNH2, which are indexed at Hydrazine with a “thio” substituent prefix; and (b) hydrazides of Hydrazinecarboxylic acid, for which the heading parent Carbonic dihydrazide, (H2NNH)2CO, (¶ 183) is employed. Hydrazides of subsidiary groups, e.g., of carboxyl substituents on aminium compounds, are indexed as substituents by use of hydrazino radicals. Cyclic hydrazides are indexed as heterocycles. Replacement (“a”) names are used when the requirements (¶ 127) are satisfied. Examples: P hC S N H N H 2 M e N H N = CPh CPh = N N H M e 10 11 Benzenecarbothioic acid, hydrazide Acetic acid, 2-acetylhydrazide (not Hydrazine, 1,2-diacetyl-) Propanedioic acid, 1-(2-phenylhydrazide) (not Propanoic acid, 3-oxo-3-(2phenylhydrazino)-) Acetic acid, 1,1′ -[2,2 ′ -(1,2,4,5-tetrazine-3,6diyl)dihydrazide] Benzenesulfonic acid, 4-amino-, 1-methylhydrazide 7 N−Ν N−Ν 12 1 12a A cN H N H A c 6 5 4 H O 2 C C H 2 C O N H N HPh Phosphazines, which contain the fragment =C=N−N=P, are indexed as phosphoranylidene hydrazones. Example: M e CH = N N = PPh 3 1 A cN H N H 6 N−Ν − N−Ν 2 Acetaldehyde, 2-(triphenylphosphoranylidene)hydrazone NHNHAc 5 4 H2N SO 2 NMe NH 2 Semicarbazones, isosemicarbazones, carbohydrazones, and semioxamazones of systematically named compounds are expressed, not by these modification terms or as substituted hydrazones, but by the general principles of substitutive nomenclature on the basis of the highest function present. Examples: M e 2 C = N N H CSN H 2 21 HO2C NHNHCON = N CO 2 H Ph CH = N N H CN H O E t Hydrazinecarbothioamide, 2-(1methylethylidene)- (not 2Propanone, thiosemicarbazone) Hydrazinecarboximidic acid, 2-(phenylmethylene)-, ethyl ester (not Benzaldehyde, 3-ethylisosemicarbazone) Diazenecarboxylic acid, 2-(4-carboxyphenyl)-, 1-[2-(4-carboxyphenyl)hydrazide] (principle: hetero acyclic parent preferred) H 2 N N H SO 2 CO 2 H O2N O CH = N N H CO N H N = CH Ph Benzoic acid, 4-(hydrazinylsulfonyl)- 7a H N 1 3 2 Carbonic dihydrazide, 2-[(5-nitro2-furanyl)methylene]-2′-(phenylmethylene)- (not 2-Furancarboxaldehyde, 5-nitro, carbohydrazone with benzaldhyde) NH O 4 3H-Indazol-3-one, 1,2-dihydro- (not Benzoic acid, 2-hydrazino-, cyclic hydrazide) Ph CH = N N H CO CO N H 2 O 4 = = = = H O − C − N H − C H 2 − C − NH − NH − C − NH − NH − C − NH − CH 2 − C − OH 1 2 3 5 6 7 8 9 10 11 12 13 = O O O O Acetic acid, 2-amino-2-oxo-, 2-(phenylmethylene)hydrazide (not Benzaldehyde, semioxamazone) 2,5,6,8,9,11-Hexaazatridecanedioic acid, 4,7,10-trioxo- 191. Imides are indexed as heterocycles with “-one” suffixes and are accordingly ranked as ketones; in the presence of higher ranking compounds, the 59 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 193 imide is expressed as a heterocyclic radical. The “diimide” of orthocarbonic acid, HN=C=NH (“carbodiimide”) is indexed at Methanediimine, and its derivatives are often to be found at amine or amide headings. Examples: O H N 71 O 1H-Azepine-2,7-dione, 3,4-dihydro(not 2-Hexenimide) O 1 9a H N 2 9b 3 O 4 1H-Benz[de]isoquinoline-1,3(2H)-dione (not 1,8-Naphthalenedicarboximide) 7 6 O 1 O 1′ HN 5 NH 5′ [3,3 ′ -Bipyrrolidine]-2,2 ′ ,5,5 ′ tetrone (not 1,2,3,4-Butanetetracarboxylic 1,2:3,4-diimide O O 6 O2 S 1 3 2 NH SO 2 4H-1,3,2-Dithiazine, dihydro-, 1,1,3,3-tetraoxide (not 1,3Propanedisulfonimide) O P rC O N H N N Butanamide, N-(2,4-dioxo-1-azetidinyl)O 6 E tN = C = N (C H 2 ) 2 N 4 N O 1 4-Morpholineethanamine, N(ethylcarbonimidoyl)- In addition, compounds with water and ammonia are not indexed at these names; they are expressed as “hydrate” and “ammoniate”. Fractional hydrates and ammoniates, such as hemi- and sesquihydrate, are named by use of a ratio as hydrate (2:1) and hydrate (2:3), respectively. Other solvates are indexed as molecular addition compounds. Often the solvate component receives the only entry; e.g., Ethanol, compd. with pyridine (1:1). Crystal forms of organic compounds containing solvents of crystallization are indexed only as the unsolvated species except when properties of the crystals themselves are being studied. “Hydrates” of carbonyl compounds are indexed as gem-diols; e.g., “acetaldehyde hydrate” is indexed as 1,1-Ethanediol. Ozonides of known structure are indexed by regular nomenclature; ozonides of unsaturated compounds are indexed at the compound headings with “ozonide” modification terms when the structures are unknown; “ozonides” of other compounds, e.g., phosphorus acid esters, are expressed as “compd. with ozone” and a ratio. Bisulfite addition compounds are named as salts of specific hydroxy sulfonic acids when the structures are known or can reasonably be assumed, otherwise as a molecular addition compound of the carbonyl compound with a phrase such as “compd. with sodium hydrogen sulfite” and a ratio in the modification. (This is an exception; an “oxo” acid salt ranks higher than an aldehyde or ketone (¶ 106) and would normally receive the preferred index entry.) Diels-Alder adducts (diene adducts) of unknown constitution are indexed like molecular addition compounds, except that the “compd. with” phrase is replaced by “adduct with.” Catena compounds (cyclic compounds with interlocking rings) are indexed at the components with a “catena compd. with” phrase and a ratio. Rotaxane is the term given to a linear molecule threaded through a cyclic molecule. The cyclic molecule is usually large, and the linear molecule usually has bulky end groups that prevent unthreading. These are indexed at the component names with a “rotaxane compd. with” phrase and a ratio. The “preferred” index name is the name given precedence in the CAS Registry System, and therefore the name which, after uninversion of the index heading if necessary, may be used among CA users in general discussions and reports. (To the index user in search of information, all the index names for an individual compound are of equal value.) For molecular addition compounds of stereoparents and their derivatives (¶ 203 I) with nonstereoparents, the preferred index entry appears at the former heading. In the absence of a stereoparent, the preferred index name is that which describes, in order of decreasing preference: (a) a component other than a common component (see list above) selected according to the Order of Precedence of Compound Classes (¶ 106); (b) a common component highest in the same order; (c) a component which does not belong to any compound class described in the “Order of Precedence of Compound Classes,” according to the earliest alphabetic position of the index name. Examples ((a) is the preferred index name in each case): 1. (a) 2,5-Cyclohexadiene-1,4-dione, 2,3,5,6-tetrachloro-, compd. with coronene (1:?) (The question mark indicates an unknown ratio; a functional compound is preferred to cyclic hydrocarbon) 2. (a) Anthracene, compd. with 2,4,6-trinitrophenol (2:1) (The cyclic hydrocarbon is preferred to a common compound of higher rank) 3. (a) Methane, 1,1′-sulfinylbis-, compd. with iodine (1:1) (by “iodine,” the molecular form I2 is implied; atomic forms are indicated, when necessary, by phrases such as “compd. with at. chlorine (1:2)”) P hN = C = N SO 2 N Me Benzenesulfonamide, 4-methylN-(phenylcarbonimidoyl)- For sulfur imides, see ¶ 200; for Phosphine imide, see ¶ 197. 192. Molecular addition compounds of neutral components are generally indexed in the Chemical Substance and Formula Indexes. The preferred name appears at the formula of each component. (The formula headings used are those of the components.) Ratios are used in the name to express stoichiometry. Some common components are not indexed unless all other components are also “common” or cannot be related to compound classes described in the “Order of Precedence of Compound Classes” (¶¶ 106); however, unesterified acids in the following list are indexed when not components of salts with bases.These common components are: Acetic acid Acetic acid, 2,2,2-trifluoroAcetonitrile Benzene Benzene, methyl- * Benzene, 1,3,5-trinitro1,3-Benzenediol, 2,4,6-trinitroBenzenesulfonic acid * Benzenesulfonic acid, 4-methylBenzoic acid Borate(1−), tetrafluoro-, hydrogen (1:1) Butanedioic acid, 2,3-dihydroxy- (all stereoisomers) 2-Butenedioic acid (of defined or undefined stereochemistry) Carbamimidothioic acid, phenylmethyl ester * Cyclohexanamine * Cyclohexanamine, N-cyclohexylEthanamine, N,N-diethyl- * Ethanedioic acid Methane, dichloro- * Methanesulfonic acid * Phenol, 2,4,6-trinitro1,2,3-Propanetricarboxylic acid, 2-hydroxy3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-4-nitro-2-(4-nitrophenyl)- * Pyridine * The preferred name is printed at the molecular formula for these compounds. 193. Nitrogen compounds. Cyclic nitrogen compounds, including lactams, sultams, and cyclic hydrazones, oximes, etc., are indexed at heterocyclic molecular skeletons (see Section B). Nitrogen-containing functional derivatives include imidic acids, amides, amines, imines, etc., for which the appropriate paragraph should be consulted. Hydroxylamine (see below) is a substitutive functional parent compound (¶ 130). Acyclic nitrogen skeletons, alone or with principal groups expressed as suffixes, are employed as heading parents for indexing purposes. Some groups, including azido, nitro, nitroso, and isocyano, are always expressed as substituent prefixes (¶ 132). aci-Nitro, HON(O)=, may be substituted; e.g., (propyl-aci-nitro) is CH3CH2CH2ON(O)=. Diazene, HN=NH; 1-Triazene, NH=N−NH2; Triazane, NH2−NH−NH2, etc., are molecular skeleton heading parents to which the principal groups except hydroxy (and its chalcogen analogs), amino, and imino can be suffixed. Hydrazine is used as a trivial name for Diazane and its derivatives. Except for hydrazides (¶ 189) and hydrazones (¶ 190), alkyl and aryl are indexed at these nitrogen parents, which rank just below nitrogen heterocycles as the highest class of nonfunctional compounds (¶ 106). Within the class, seniority depends first on the number of hetero atoms, then on maximum unsaturation. When more preferred compound classes (including all those expressed by means of function suffixes) are present, the nitrogen skeletons are named as substituent prefixes, some of which have trivial names. ¶ 193 Examples (See also ¶ 161): HN=N− −N=N− − N = N (O ) − Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Br N = N N ( CH O ) N ( CH O ) N = N 1 23 4 5 6 60 Br diazenyl 1,2-diazenediyl 1-oxidodiazenyl 6 1,5-Hexazadiene-3,4-dicarboxaldehyde, 1,6-bis(4-bromophenyl)1′ 6′ 2-oxidodiazenyl Η2NNH− Η2NN= −NHNH− −NHN= =NN= Η2NNHNH− Η2NN=N− ΗN=NNΗ− −N=NNΗ− Η2NNHNHNH− =NNHNHN= H 2 N C( = N H ) NHN=N 1 C( = N H ) N H 2 hydrazinyl hydrazinylidene 1,2-hydrazinediyl 1-hydrazinyl-2-ylidene 1,2-hydrazinediylidene triazanyl 1-triazen-1-yl 2-triazen-1-yl 1-triazene-1,3-diyl tetrazanyl 1,4-tetrazanediylidene Benzenecarboximidamide, 4,4 ′ (1-triazene-1,3-diyl)bis- Formazan is a trivial name that describes the tautomeric compound H2N− N=CH−N=NH. Beginning with the Thirteenth Collective period, the use of formazan and its associated prefixes, formazano and formazanyl, has been discontinued and compounds containing the formazan residue are named systematically. Examples: H 2 N − N = CH − N = N H Diazenecarboxaldehyde, hydrazone (formerly Formazan) Ethanone, 1-(2-methyldiazenyl)-, hydrazone Ethanone, 2-hydroxy-1-(2-methyldiazenyl)-, hydrazone H 2 N − N = C( CH 3 ) − N = N − CH 3 H 2 N − N = C( CH 2 O H ) − N = N − CH 3 Hydrazides (¶ 189) and hydrazones (including azines) (¶ 190) are excluded from the following examples. Examples: H2NNHCO2H 21 I CH = N − N = C − N = N − CH 3 Hydrazinecarboxylic acid 1,2-Hydrazinedicarboxylic acid Hydrazinecarboxamide, N-methylHydrazine, 1,1,2-triethylHydrazine, hydroxyHydrazine, (3-nitro-2-thienyl)(principle: preferred hetero atom in heading parent (¶ 138)) HOOC HOOC Cl Diazenecarbohydrazonyl iodide, 2-methyl-N-(phenylmethylene)- HO2CNHNHCO2H 1 2 H 2 N N H C O N H Me 21 N N H − N = CH − N = N CO O H Et2NNHEt H2NNHOH S NHNH2 Benzoic acid, 4-[2-[[2-(4-carboxyphenyl)diazenyl]methylene]hydrazinyl]-2-chloroCl N H − N = CH − N = N CO O H NO2 N H N Me 2 8 9 9a 1 Benzoic acid, 4-[2-[[2-(4-carboxyphenyl)hydrazinylidene]methyl]diazenyl]]-2-chloroCH = N − N = C( CH 3 ) − N = N − CH 3 Acridine, 9-(2,2-dimethylhydrazinyl)- 10a 5 N 10 4a P hN = N SO 3 H P hN = N C O N H 2 2 1 N 6 Diazenesulfonic acid, 2-phenylDiazenecarboxamide, 2-phenyl- Benzaldehyde, 2-[1-(2-methyldiazenyl)ethylidene]-, hydrazone Hydroxylamine, H2NOH; Thiohydroxylamine, H2NSH, etc., are substitutive parent compounds; i.e., substituent prefixes but (usually) not substituent suffixes may be attached to them. N-Ylidene derivatives are oximes (¶ 195), imidic acid derivatives (¶ 165), etc. In general, N-alkyl and N-aryl derivatives of Hydroxylamine are indexed as amines; N-acyl derivatives as amides; and S-amino derivatives of Thiohydroxylamine are indexed as sulfenamides. When the nitrogen atom is unsubstituted, O-derivatives are usually indexed at Hydroxylamine, etc. Examples: H 2 N O SO 3 H PhN = N (O ) 1 CO 2 H Benzoic acid, 4-(1-oxido2-phenyldiazenyl)- HOCO N( O) = 2 Benzoic acid, 4,4′-(1,2-dioxido1,2-diazenediyl)bis- N (O ) = N F 1 2 Sulfuric acid, monoazanyl ester Acetic acid, azanyl ester Carbonic acid, monoazanyl ester Carbamic acid, azanyl ester Hydroxylamine, O-butyl- Diazene, 1-(2-chlorophenyl)2-fluoro-, 1-oxide H2NOAc Cl H 2 N O CO 2 H H2NN=NAc Acetic acid, 1-triazen-1-yl ester Ethanimine, 1-[3-(methylsulfonyl)triazanyl]- H 2 N O CO N H 2 MeSO 2 N H N H N H C( = NH) Me 3 2 1 Bu O N H 2 61 H 2 N O (C H 2 ) 2 O N H 2 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Hydroxylamine, O,O ′ -1,2-ethanediylbisEthanesulfenamide Benzenamine, N-hydroxyAcetamide, N-mercaptoCarbamic acid, N-hydroxyUrea, N-hydroxyBenzenesulfonamide, N-hydroxyO 6 ¶ 196 Br 1 E tSN H 2 P hN H O H A cN H S H HONHCO2H HONHCONH2 P hS O 2 N H O H N SCO SH 2,5-Cyclohexadiene-1,4-dione, 2,6-dibromo-, 4-[S-(thiocarboxy)thiooxime] Br M e CH = N O SO 3 M e Hydroxylamine-O-sulfonic acid, N-ethylidene-, methyl ester Hydroxylamine and its chalcogen analogs rank lowest among the nonfunctional nitrogen parents. In the presence of more preferred compound classes, the radicals (aminooxy), (aminothio), (hydroxyamino), etc., are employed. Examples: HONHCOCO2H 196. Oxygen compounds include a wide range of compound classes: acids, anhydrides, esters, alcohols, salts, metal oxides, etc. These are discussed in other sections and paragraphs. Cyclic oxygen compounds are indexed as heterocycles; these include cyclic esters, anhydrides, ethers, and oximes, as well as lactones, sulfones, etc. Examples: 1 3 O Et Et 1 Oxirane, 2,2-diethyl- (not Butane, 1,2-epoxy-2-ethyl-) Acetic acid, 2-(hydroxyamino)2-oxo3 H2NOCH2NHNHNH2 1 2 Triazane, 1-[(aminooxy)methyl]- Et 4 O O 2-Oxetanone, 4-ethyl- (not Pentanoic acid, 3-hydroxy-, β-lactone; see ¶ 185) 194. Organometallic compounds. Organic derivatives of germanium, tin, lead, antimony, and bismuth are indexed at hydride heading parents (see ¶¶ 181, 199). Cyclic derivatives of these metals with standard substitutive valencies are indexed as heterocycles. Example: 7a 1 2 1 7a O O O 3 1,3-Benzodioxol-2-one (not Carbonic acid, cyclic 1,2-phenylene ester; see ¶ 185) 4 1 G eH 3 7 1H-2-Benzogermole O 6 7-Oxabicyclo[4.1.0]heptane (a Von Baeyer ring system; see ¶ 155) 4 Acyclic metal derivatives, other than acetylides (¶ 219) and those indexed at metal hydride names, are indexed at the metal element name. Such names are ranked as neutral coordination compounds (¶ 215) and all functional compounds are expressed as substituent prefixes. When all metal atoms cannot be expressed by the heading parent, elements other than those of Groups IVA and VA are expressed as “-io” radicals, e.g., sodio, magnesio, aurio, lithio, when the metal replaces a single hydrogen. No hydrogen or other “substituent” is implied by these radical names, and atoms or groups attached to them must be expressed. Examples: L i-P h Acyclic ethers (including acetals and ortho esters) are indexed by replacement (“a”) nomenclature if the requirements (¶ 127) are satisfied. Example: − − 4 CH 3 9 8 7 6 5 CH 3 3 2 1 12 CH 3 − CH 2 − Ο − CH − O − CH 2 − CH 2 − Ο − CH − O − CH 2 − CH 2 − O H 11 10 3,5,8,10-Tetraoxadodecan-1-ol, 4,9-dimethyl- (not Acetaldehyde, 1,2-ethanediyl ethyl 2-hydroxyethyl diacetal) When “a” names are not permitted, acyclic ethers are indexed at heading parents (functional parent compounds, hydrocarbons, etc.) by use of “oxy” radicals, including the elided radicals (¶ 107) methoxy, ethoxy, propoxy, butoxy, and phenoxy. Examples: E tO M e Lithium, phenylPhosphonium, [3-(bromomercurio)-1-propen-1-yl]trimethyl-, bromide (1:1) Me 3 P + C H = C H C H 2 HgBr • B r − 195. Oximes contain a bivalent hydroxylamine residue, =N−OH. When this residue has replaced oxygen in carboxylic acids, acid halides, and amides, the compounds are named as N-hydroxy derivatives of imidic acids (¶ 165), imidoyl halides (¶ 170), and imidamides (¶ 171). Cyclic oximes are indexed at heterocyclic parents, e.g., Isoxazole. Acyclic oximes derived from aldehydes and ketones expressed as principalgroup suffixes are expressed by “oxime” terms in the index modifications at the carbonyl-containing heading parents. When the carbonyl group is expressed as a substituent, it is replaced by the (hydroxyimino) radical, HO−N=. O-Alkyl, O-aryl, and O-acyl oximes are named as such in the modification or as an “-oxyimino” radical. Oximes derived from Hydroxylamine-O-sulfonic acid (¶ 193) are named as substituents of that heading parent. Examples: H2C=NOH Ethane, methoxy- (not Ether, ethyl methyl) Ethane, 1,1′-oxybis- (not Ethyl ether) Benzene, 1,1′-[oxybis(methylene)]bis- Et2O 1 CH 2 − Ο − CH 2 1′ Ο ( CH 2 ) 1 1 M e Naphthalene, 2-(dodecyloxy)(principle: ring preferred to chain (¶ 138)) Formaldehyde, oxime Me Ph 2 C = N O H NOH 7a 1 Methanone, diphenyl-, oxime 1,3-Isobenzofurandione, monooxime O 1 O 3 CH 2 Ο ( CH 2 ) 2 O Oxirane, 2-[[2-(2-methylphenoxy)ethoxy]methyl]- (principle: preferred ring) O2 3 Cl − CH 3 − C − Ο − CH = CH 2 Ο − CH = CH 2 − 4 CO2H 1 6 Ethene, 1,1 ′ -[(1-chloroethylidene)bis(oxy)]bis- (principle: unsaturation) Benzoic acid, 3-[(hydroxyimino)methyl]CH=NOH O 4 1 O 1′ O MeC H = N O Me Acetaldehyde, O-methyloxime Benzene, 1,1′-oxybis[4-phenoxy(principles: centrality and multiplication) ¶ 196 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 O = O = 62 C H 3 − C H 2 − O − C H 2 − CH 2 − S − S − CH 2 − CH 2 − O − CH 2 − CH 3 Disulfide, bis(2-ethoxyethyl) (an “a” name cannot be used; only three hetero units (¶ 127) are present) O Me O OMe C − O − O − C − CH 2 − CH 2 − N = N − CH 2 − CH 3 Diazene, [3-(benzoyldioxy)-3oxopropyl]ethyl− − − HOO−C−O−O−C−O−O−C−O−O−C−ΟOH − − − CH2−CH3 CH2−CH3 CH2−CH3 CH2−CH3 − − CH2−CH3 CH2−CH3 CH2−CH3 CH2−CH3 Benzene, 1-methoxy-2-(4-methoxyphenoxy)- (principle: lowest locants for substituent prefixes) Hydroperoxides, ROOH, follow alcohols (including phenols) in order of precedence (¶ 106). They are indexed at the radicofunctional heading parent Hydroperoxide. No hyphen follows the substituent radical (¶ 108) unless the heading parent is being multiplied by a prefix such as “bis”. In the presence of more preferred compound classes, or when the HOO− group is attached to a hetero atom other than silicon, a hydroperoxy radical is employed. The chalcogen analogs R−S−OH and R−S−SH are indexed as sulfenic acids and sulfenothioic acids, respectively (¶ 165). Thiohydroperoxide is the heading parent for R−O−SH compounds. Hydrotrioxide, Hydrotetraoxide, etc., heading parents are treated in a similar manner, and hydrotrioxy and hydrotetraoxy radicals can be used as substituent prefixes. Examples: E tO O H HOO 8 9 4b 4a Hydroperoxide, 1,1′-[dioxybis[(1ethylpropylidene)dioxy(1-ethylpropylidene)]]bisO = O = O = O H O − C − CH 2 − CH 2 − C − O − O − C − CH 2 − CH 2 − C − O H = Butanoic acid, 4,4 ′ -dioxybis[4-oxoO CH 3 − C − O − O − CH 2 − CH 3 MeOOF = Ethaneperoxoic acid, ethyl ester Peroxyhypofluorous acid, methyl ester O = O = Hydroperoxide, ethyl (the uninverted name is Ethyl hydroperoxide) OOH 9a 1 F−C−O−O−C−F O = O = Peroxydicarbonic difluoride Thioperoxide, S-acetyl O-benzoyl Hydroperoxide, 1,1′-(9H-fluoren-9ylidene)bis- CH 3 − C − S − O − C H O O C H 2 C O Ph Ethanone, 2-hydroperoxy-1phenylPiperidine, 1-hydroperoxy- The heading parents Trioxide, Tetraoxide, etc., are treated analogously and, in the presence of more preferred compound classes, radicals such as (methyltrioxy), CH3−O−O−O−, are used. Example: MeOOOMe Trioxide, dimethyl NOOH − CH3 CH3 Acyl hydroperoxides are peroxy acids (¶ 165). Peroxides, R−O−O−R ′ (R and R ′ = alkyl or acyl), are named at the radicofunctional heading parent Peroxide unless a replacement (“a”) name (¶ 127) is appropriate. Cyclic peroxides are indexed as heterocycles and are ranked in accordance with the seniority of ring systems (¶ 138). Acyclic peroxides rank with the nonfunctional oxygen parents (¶ 106) and in the presence of a more preferred compound class are expressed by “dioxy” radicals. Acyl alkyl (and acyl silyl) peroxides are esters of peroxy acids. Symmetrical diacyl peroxides derived from “oxo” acids are named at acid, acid halide, etc., heading parents such as Peroxydiphosphonic acid. Dithio peroxides are indexed at Disulfide (¶ 200); R−S−O−R ′ compounds are named as esters of sulfenic acids (¶ 165). The corresponding diacyl compounds are indexed at Thioperoxide. Examples: − − − − CH3 3 − H3C−C−O−O−OH CH3 − CH3 − C − O − SH Thiohydroperoxide, O-(1-methyl-1phenylethyl) Hydrotrioxide, 1,1-dimethylethyl 197. Phosphorus and arsenic compounds. The fundamental phosphorus and arsenic “oxo” acids are shown in Table VI. By use of replacement nomenclature (¶ 129) in which oxo and hydroxyl groups are replaced by other chalcogen atoms or nitrogen groups, a large number of acids, acid halides, amides, etc., can be named. Phosphorous acid is the heading parent when all three hydroxyl groups are involved in anhydride, ester, or salt formation; otherwise the tautomeric Phosphonic acid is the preferred heading parent. Similarly, Phosphinic acid is preferred over the tautomeric Phosphonous acid. Metaphosphorous acid is the name used for the unsubstituted acid and its ester and salts, but Phosphenous acid is the fundamental name from which replacement analogs are derived. Metaphosphoric and Phosphenic acids stand in the same relationship, except that the special names Metaphosphimic acid, Thiometaphosphimic acid, etc., are used for (HO)P(O)(=NH) (or (HO)2P ≡ N) and its chalcogen analogs. TABLE VI FUNDAMENTAL MONONUCLEAR PHOSPHORUS AND ARSENIC OXO ACIDS “Trivalent” acids (HO)3P (HO)2HP (HO)H2P HOPO Phosphorous acid Phosphonous acid Phosphinous acid Phosphenous acid Metaphosphorous acid (HPO2) (HO)3As (HO)2HAs (HO)H2As HOAsO Arsenous acid Arsonous acid Arsinous acid Arsenenous acid CH3 6 7 8 9 10 11 CH 3 CH3 17 − − − CH3 CH3 CH 3 3,4,6,9,12,14,15-Heptaoxaheptadecane, 2,2,5,5,13,13,16,16-octamethyl1 12 a 12 b 5 8 9 4 O O6 O 7 − CH3−C−O−O−C−O−CH2−CH2−O−CH2−CH2−O−C−O−O−C−CH3 1 2 45 12 13 14 15 16 CH3 Dibenzo[d,f ][1,2]dioxocin-5,8-dione (HO)3PO (HO)2HPO (HO)H2PO HOPO2 “Pentavalent” acids Phosphoric acid Phosphonic acid Phosphinic acid Phosphenic acid Metaphosphoric acid (HPO3) (HO)3AsO (HO)2HAsO (HO)H2AsO HOAsO2 Arsenic acid (H3AsO4) Arsonic acid Arsinic acid Arsenenic acid O Me 2 C H O O C H Me 2 E tO O Me Peroxide, bis(1-methylethyl) Peroxide, ethyl methyl (the uninverted name is Ethyl methyl peroxide) O = O = C H 3 − C − O − O − C − CH 3 O = C − O − O − SO 3 H Peroxide, diacetyl Examples: Peroxide, benzoyl sulfo ( Ph N H ) 2 P( O ) O H Phosphorodiamidic acid, N,N ′ -diphenyl- 63 Me 2 N N H P(O )(O H ) 2 21 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Phosphorohydrazidic acid, 2,2dimethylPhosphorodiamidimidic acid, N,N ′ -dimethylArsinous acid, diphenylArsenamidic acid, N-ethylCl 2 HAs (NC)H 2 As ClAs=NH BrAsO Cl 3 PO ClF 2 PO (OCN) 3 PO Cl 3 PS OP ≡ N Arsonous dichloride Arsinous cyanide Arsenenimidous chloride Arsenenous bromide Phosphoric trichloride ¶ 197 MeN H P(O H )( = N H ) NHMe N N′′ N′ P h 2 A sO H E tN H A s(O )(O H ) 2 Esters and anhydrides are indexed by the usual rules. Phosphorous, Phosphoric, Phosphorothioic and Phosphorodithioic acids are “Class I” acids; their esters with a single alcohol or thiol of “Class II” (¶ 185) are indexed at the alcohol name, but “mixed” esters are indexed at the phosphorus acid unless a more preferred compound class (e.g., carboxylic acid, aminium compound) is present. All cyclic esters are indexed as heterocycles. Examples: (E tO ) 2 P O (C H 2 ) 2 N H 2 Phosphoric chloride difluoride Phosphoric triisocyanate Phosphorothioic trichloride Phosphoric nitride Phosphorous acid, 2-aminoethyl diethyl ester Ethanol, 2-chloro-, phosphite (3:1) Phosphonic acid, monomethyl ester Phosphonothioic acid, ethyl-, O,S-diethyl ester Esters and anhydrides of cyclic oligomers of metaphosphorus acids are indexed as heterocycles. Examples: Ph O P O 4 3 [C l(C H 2 ) 2 O ] 3 P Me N 1 2P O O Ph H P (O )(O H )O Me N Me Me N 1 4 3 1,3,2,4-Diazadiphosphetidine, 1,3dimethyl-2,4-diphenoxy-, 2,4-dioxide E tP (O )(O E t)SE t 6 2 − − H3C−As−S−As=S CH3 − CH3 CH3 Arsinodithioic acid, dimethyl-, anhydrosulfide with dimethylarsinothious acid MeOP MeN 5 PO M e NMe P OMe 1 1,3,5,2,4,6-Triazatriphosphorine, 1,2,3,4,5,6-hexahydro-2,4,6trimethoxy-1,3,5-trimethyl- Nonacidic mononuclear arsenic and phosphorus names are derived from the acid names in the usual way by expressing the highest function as a class term, e.g., “amide,” “chloride,” and the other replacement terms in alphabetical order within the main part of the name. The descending order of precedence for class terms is: hydrazide, halide (all considered equivalent, and cited in alphabetical order), azide, amide, cyanide, isocyanide, cyanate, thiocyanate (etc.), isocyanate, isothiocyanate (etc.), nitride, imide. Nonacidic analogs of phosphoric acid in which an oxo and hydroxyl group have been replaced by ≡ N, are named at Phosphonitrile headings. Examples: (H 2 N) 3 P=NH Cl 3 P=NH (H 2 N)Cl 2 PS (H 2 N)BrClPO (OCN)ClFPO (H 2 N) 2 (N 3 )PO (H 2 N) 2 (NC)PO (H 2 NNH)F 2 PO (H 2 N) 3 P Cl 3 P ClF 2 P (NC)H 2 P (SCN)H 2 P H 2 NPS ClP=NH (H 2 N)ClHP=NH Cl 2 P ≡ N (H 2 N) 3 AsO (H 2 N)ClHAs=NH (NCS) 2 HAsO (H 2 N)H 2 As=NH Cl 3 As Phosphorimidic triamide Phosphorimidic trichloride Phosphoramidothioic dichloride Phosphoramidic bromide chloride Phosphorisocyanatidic chloride fluoride Phosphorodiamidic azide Phosphorocyanidic diamide Phosphorodifluoridic hydrazide Phosphorous triamide Phosphorous trichloride Phosphorous chloride difluoride Phosphinous cyanide Phosphinous isothiocyanate O P E tO O 5 O 6 O 2P 4 O O3 OEt O P( O ) ( O E t) 2 P 1,3,5,2,4,6-Trioxatriphosphorinane, 2-[(diethoxyphosphinyl)oxy]4,6-diethoxy-, 2,4,6-trioxide Phosphorus and arsenic molecular skeletons other than those named as acids and acid analogs are indexed as heterocycles or at acyclic hydride names: Phosphine, PH3; Arsine, AsH3; Phosphorane, PH5; Arsorane AsH5; Diphosphine, H2P−PH2; Triarsine, H2As−AsH−AsH2; etc. Oxo, thio (etc.), and imino derivatives of Phosphorane and Arsorane are indexed at additive heading parents. Examples: H 3 PO H 3 AsSe H 3 P=NH HPO 2 Phosphine oxide Arsine selenide Phosphine imide Phosphine oxide, oxo- (not Phosphorane, dioxo-) Oxides, etc., of Diphosphine, Diarsine, Triphosphine, etc., are indexed by use of “oxide” and “sulfide” terms, with locants if necessary, in the modification. Acid derivatives of one of the phosphorus atoms are indexed at acid parents when names based on the phosphorus chains are impracticable. Example: PhPHP(O)H 2 Et 3 P(Cl)P(O)Cl 2 Diphosphine, phenyl-, 2-oxide Phosphonic dichloride, P-(chlorotriethylphosphoranyl)- Phosphenothious amide Phosphenimidous chloride Phosphonamidimidic chloride Phosphonitrile chloride (not Phosphoronitridic dichloride) Arsenic triamide Arsonamidimidic chloride Arsonic dithiocyanate Arsinimidic amide Arsenous trichloride Me 2 AsCO 2 H EtAsMe 2 =NH F 4 PNHMe Derivatives of Phosphine and other phosphorus and arsenic molecular skeleton parents are named substitutively by use of suffixes and prefixes. Examples: (HO) 2 P(O)CO 2 H Phosphinecarboxylic acid, 1,1-dihydroxy-, oxide Phosphoranamine, 1,1,1,1-tetrafluoro-N-methylArsinecarboxylic acid, 1,1-dimethylArsine imide, As-ethyl-As,As-dimethyl- ¶ 197 (EtO) 5 P Ph 3 As(OAc) 2 HPO MeAsS MePHPHMe Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Phosphorane, pentaethoxyArsorane, bis(acetyloxy)triphenylPhosphine, oxoArsine, methylthioxoDiphosphine, 1,2-dimethylDiarsine, 1,2-dimethyl-1,2-diphenylDiarsene, 1,2-dimethyl- 64 In the presence of more preferred compound classes, phosphorus and arsenic acids and hydrides are expressed by the following substituent radicals (*denotes a radical which requires bis, tris, etc., (and parentheses) instead of di, tri, etc., when more than one is present): H2P− H2P(O)− H2P(S)− H2P(=NH)− HP(≡N)− H4P− HP= HP(O)= P(O)≡ *phosphino *phosphinyl phosphinothioyl phosphinimyl phosphononitridyl *phosphoranyl phosphinidene *phosphinylidene *phosphinylidyne H2As− H2As(O)− H2As(S)− H2As(=NH)− HAs(≡N)− H4As− HAs= HAs(S)= As≡ *arsino *arsinyl arsinothioyl arsinimyl arsononitridyl *arsoranyl arsinidene arsinothioylidene arsinidyne (Me)(Ph)As − As(Ph)(Me) MeAs=AsMe Polyphosphorus acids (anhydrides of the mononuclear acids) and their replacement analogs do not follow the rules described for the mononuclear acids. They are given traditional inorganic names, and many cross-references will be found at mononuclear names (see also ¶ 219). (Polyarsenic acids are named analogously.) Examples: (HO) 2 P(O)OP(O)(OH) 2 (HO) 2 P(O)P(O)(OH) 2 (HO)HP(O)OP(O)(OH) 2 (HO) 2 POP(O)(OH) 2 (HO) 2 POP(OH) 2 (HO) 2 P(O)NHP(O)(OH) 2 Diphosphoric acid Hypophosphoric acid Isohypophosphoric acid Diphosphoric(III,V) acid Diphosphorous acid Imidodiphosphoric acid The above are substitutive; the following are not, and can be used only as simple radicals (¶ 132): P(O)− P(O)2− (HO)2P(O)− −P(O)(OH)− phosphoroso phospho phosphono phosphinico (multiplying radical only) As(O)− As(O)2− arsenoso arso (HO)2As(O)− arsono −As(O)(OH)− arsinico (multiplying radical only) (HO) 2 P(O)OP(O)(OH)NHP(O)(OH)OP(O)(OH)2 P ′ -Imidotetraphosphoric acid (H 2 N) 2 P(O)NHP(O)(OH) 2 P,P-Diamidoimidodiphosphoric acid Radicals from polynuclear arsenic and phosphorus hydrides are formed like the carbon analogs. Examples: H 2 PPH − diphosphinyl 1,2-diphosphinediyl 1,2-diphosphinediylidene 1,2-diphosphenediyl 1,2-diarsenediyl 1,4-tetraphosphinediyl Line formulas are used with thio, seleno, and telluro analogs of polyphosphorus acids to indicate the number and positions of sulfur (etc.) atoms. Thio, etc., prefixes are placed at the beginning of the name without multiplicative terms; e.g., Thiodiphosphorous acid ([(HO) 2P] 2S) ; Thiodiphosphoric(III,V) acid ((HO) 2POP(S)(OH) 2); Thioperoxydiphosphoric acid ([(HO) 2P(S)] 2S 2); Thioimidodiphosphoric acid ([(HO) 2P(S)] 2NH) . When all acid groups have been replaced, the compounds are named as halides, amides, etc. The phosphoric halides and halogenoids are named by phosphoryl terms, the phosphoric amides by single-word heading parents. The phosphorous analogs of both classes are indexed at Phosphorous binary heading parents with a multiplicative prefix for the class term. Examples: Cl 2 P(O)OP(O)Cl 2 Diphosphoryl chloride (the phosphorous analog is named Diphosphorous tetrachloride) Diphosphorous tetraamide (the phosphoric analog is named Diphosphoramide) Diimidotriphosphoramide − PHPH − =PP= − P=P − − As=As − − PH(PH) 2 PH − (H 2 N) 2 POP(NH 2 ) 2 O = − O − = O − = 198. Salts. Metal salts of acids and of other compounds having replaceable hydrogen on chalcogen atoms (whether expressed in the heading parent, in the substituents, or in a previous modification phrase) are indexed by use of salt terms in the modification. Ratios and Ewens-Bassett numbers are used, but locants are never cited. In the presence of hetero atom groups capable of forming chelate rings, salts of aluminum, beryllium, gallium, indium, magnesium, thallium, and the transition metals with acids (except polybasic hydroxy acids) are named by coordination nomenclature (¶ 215). Examples: AcOH • Na H 2 N − P − N H − P − N H − P − NH 2 NH3 NH3 NH 3 Acetic acid, sodium salt (1:1) OH • 2K HO 1,4-Benzenediol, potassium salt (1:2) Phosphonic acid, P-phenyl-, monoethyl ester, potassium salt (1:1) Methanol, bismuth(3+) salt (3:1) Benzoic acid, 2-chloro-, 2-hydroxyethyl ester, lithium salt (1:1) In the order of precedence of compound classes (¶ 106), phosphorus and arsenic acids are functional heading parents, which fall below the acids expressed as principal functions (carboxylic, sulfonic, etc.) but above the highest nonacid group (acid halides). Phosphorus acids as a group rank just above arsenic acids. Within each group, seniority is dependent on (a) the greatest number of acid groups; (b) the greatest number of nuclear phosphorus or arsenic atoms; (c) the highest oxidation state (5+) of these atoms; (d) the most preferred atoms (Table I, ¶ 128) attached to the nuclear atoms; (e) the greatest number of such preferred atoms; (f ) the nature of less preferred atoms. A partial list of acids in descending order of precedence is: Triphosphoric, Diphosphoric, Imidodiphosphoric, Diphosphorous, Phosphoroperoxoic, Phosphoric, Phosphorothioic, Phosphorodithioic, Phosphorous, Phosphorochloridic, Phosphorohydrazidic, Phosphoramidic, Phosphonic, Phosphinic, Phosphinous acid. (Chalcogen analogs of each acid immediately follow it in descending order of increasing replacement of oxygen by sulfur, selenium, and tellurium.) For the choice between tautomeric pairs such as Phosphorous and Phosphonic acids, also see above. Nonacid analogs are ranked according to their class, e.g., halide, amide; then on the multiplicity of their class, e.g., a diamide is preferred over a monoamide; then on the remaining criteria set out above for the acids. Ph P( O ) ( O H ) O E t • K 3 M e O H • Bi 3 Cl + CO 2 ( CH 2 ) 2 O H • L i When a metal (except Sb3+, Bi3+, Ge4+, Sn4+, or Pb4+) has replaced hydrogen atoms attached to nitrogen, phosphorus, arsenic or antimony in molecular skeletons, they also are named as salts, e.g., Piperidine, potassium salt (1:1); Acetamide, sodium salt (1:1); Phosphine, cyclohexyl-, lithium salt (1:1); but unsubstituted Hydrazine, Phosphine, and Arsine afford the binary heading parents Sodium hydrazide (NaN2H3); Lithium arsenide (LiH2As); Aluminum phosphide; etc. 65 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 N • H 2 Se O 4 ¶ 198 Except for those cyclic derivatives of germanium, tin, lead, antimony, and bismuth which are treated as heterocycles (¶ 194), cyclic metal salts of two or more compounds, as well as mixed acyclic salts, are named by coordination nomenclature (¶ 215). Metal salts of radical anions and of certain delocalized structures, e.g., β-dicarbonyl compounds and nitro alkanes, are indexed by citing the ion term in the modification followed by the metal name and a ratio. Examples: • − Selenic acid, compd. with pyridine (1:1) 1-Butanol, 2-amino-, ethanedioate (1:1) Phenol, 4-amino-, 1-acetate, acetate (1:1) M e CH 2 CH ( N H 2 ) CH 2 O H • H O 2 CCO 2 H 4 2 1 • Na+ Naphthalene, radical ion(1−), sodium (1:1) AcO NH2 • AcOH O2N−CH−NO2 • N a − + Methane, dinitro-, ion(1−), sodium (1:1) For salts of amines, etc., with alcohols and thiols, the phrase “compd. with” and a ratio are used. Examples: N CH 3 • E tO H O = CH3−C−CH−C−CH3 • K + − O = 2,4-Pentanedione, ion(1−), potassium (1:1) Ethanol, compd. with 2-methylpyridine (1:1) Uninverted names for metal salts of acids and esters depend on the structure and name of the acid or ester. The metal is cited first when there is a free acid group remaining in the parent that can take an “ate” or “ite” suffix. If there is no acid group available in the parent, e.g., all acid functions of the parent are esterified, the metal follows the acid name. When the acid is one that requires a line formula, the acid name is placed first. Examples: sodium acetate (1:1) potassium carbonate (1:1) calcium ethyl phosphate (1:1) zinc methyl sulfate (1:2) 1,4-diethyl 2-sulfobutanedioate sodium salt (1:1) potassium 2-hydroxybenzoate (1:1) calcium 4-aminobenzoate (1:2) perboric acid (HBO(O2)) sodium salt (1:1) In uninverted names of alcohol or amine metal salts, the alcohol or amine is cited first, e.g., 2,6-dimethylphenol lanthanum(3+) salt (3:1) or 2-ethoxybenzenamine sodium salt (1:1). Amine, phosphine, etc., salts of acids, alcohols, thiols, etc., in general are indexed in the Chemical Substance Index at the preferred name. The preferred name is also cited at each of the component formulas in the Molecular Formula Index. Exceptions are salts of ammonia, indexed only as ammonium salts at the acid headings, and the “common components” of molecular addition compounds (¶ 192) together with the following common acids: hydriodic, hydrobromic, hydrochloric, hydrofluoric, nitric, nitrous, perchloric, phosphoric, phosphorous, sulfuric, and sulfurous. Entries are not made for these components except for salts that contain only “common components,” in which case a single entry based on the rules for molecular addition compounds (¶ 192) is made. At the acid heading, a “compd. with” phrase appears in the modification. Example: N H 2 • A c OH Salts of aminium compounds and other substitutive cations are indexed by combining the “-ium” heading and the anion term, named according to the rules already described, (¶¶ 180, 184). The preferred name appears in the Chemical Substance Index and at each of the components in the Formula Index except for the following common anions: (a) halide and halogenide simple anions, e.g., bromide, cyanide, thiocyanate, azide; (b) chalcogenide anions, e.g., hydroxide, sulfide; (c) anions derived from acetic acid, benzenesulfonic acid, 4-methylbenzenesulfonic acid, 1,1,1-trifluoromethanesulfonic acid, methanesulfonic acid, carbonic acid, phosphoric acid, nitric acid, nitrous acid, sulfuric acid, sulfurous acid, and 2,4,6-trinitrophenol; (d) methyl sulfate (MeOSO3− ), and ethyl sulfate (EtOSO3− ); (e) tetrafluoroborate(1−) (BF4− ), tetraphenylborate(1−) (BPh4− ), and hexafluorophosphate(1−) (PF6−). Ternary salts of this kind are indexed by citing the terms in alphabetical order in the modification, cations first, then anions. In molecular addition compounds, the “-ium” salt is cited in uninverted form. Examples: Me4N + • Br − M e 4 N + • M e CO S − Methanaminium, N,N,N-trimethyl-, bromide (1:1) Methanaminium, N,N,N-trimethyl-, ethanethioate (1:1) Arsonium, tetraethyl-, cyclohexanecarboxylate (1:1) CO 2 − Et4As+ • −O2C Me +N • CO 2 H Pyridinium, 1-methyl1,2-benzenedicarboxylate (1:1) Acetic acid, compd. with cyclohexanamine (1:1) − Me2N+ +N M e 2 • 2 Piperazinium, 1,1,4,4-tetramethyl-, cyclopentadienide (1:2) At index headings for nitrogenous substances, and those containing trivalent phosphorus or arsenic, an “-ate”, “-ite”, or “-ide” term is normally cited in the modification, but when the acid has a synonym line formula, or is an acid ester indexed at a “Class II” alcohol name, a “compd. with...” phrase is used instead. Examples: Me 2 A sH • H C l M e 4 N + • − N H Ph Methanaminium, N,N,N-trimethyl-, salt with benzenamine (1:1) Methanaminium, 1-hydroxy-N,N,Ntrimethyl-, perchlorate (1:1) Piperazinium, 1,1-dimethyl-, 2,2,2-trifluoroacetate hydrochloride (1:1:1) (¶ 281A) − • Arsine, dimethyl-, hydrochloride (1:1) Benzenamine, phosphate (1:1) M e 3 N + CH 2 O H • ClO 4 − PhN H 2 • H 3 P O 4 HN +N M e 2 • F 3 CCO 2 − • H Cl N C H − C H 2 − NEt 2 • HO 2 CCO 2 H CH3 Me4P • Me4As • 2 + + ( N C) 2 C C( CN ) 2 Cl(CH2)2OP(O)(OH)2 − 2-Pyridineethanamine, N,Ndiethyl-β-methyl-, ethanedioate (1:1) • H2N CONH 2 Phosphonium, tetramethyl-, tetramethylarsonium, salt with 2,2′-(2,5-cyclohexadiene-1,4diylidene)bis[propanedinitrile] (1:1:2) N 2 + • C l − • x Co Cl 2 Benzamide, 4-amino-, compd. with 2-chloroethyl dihydrogen phosphate (1:1) Cl Benzenediazonium, 4-chloro-, chloride, compd. with cobalt chloride (CoCl2) (1:1:?) ¶ 199 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Examples: SiCl 4 M e 3 SiCN M e 3 Sn CN 66 199. Silicon, germanium, tin, and lead compounds are indexed (a) as heterocyclic compounds, (b) as derivatives of acyclic hydride parents such as Germane or Disilane, (c) as special acyclic parents such as Tristannathiane or Tetrasiloxane, or (d) as silicic acids. Heterocyclic compounds are indexed by the usual methods (¶¶ 146, 149). Examples: 1 6 Silane, tetrachloroSilanecarbonitrile, trimethylStannanecarbonitrile, trimethylSilanol, 1,1,1-trimethyl1-Disiloxanol, 1,1,3,3,3-pentaethylGermanamine Silanol, 1,1′-methylenebis[1,1-dimethylOH 2 Si O 2 G eH 2 O3 4H-1,3,2-Dioxagermin M e 3 SiO H E t 3 SiO SiE t 2 O H 2 H2Sn H2Sn 5 6 H2 Sn 1 4 S nH 2 S nH 2 3 Hexastannin, hexahydro- H3GeNH2 ( H O SiM e 2 ) 2 CH 2 1 6 Sn H2 O H2 Si 5 1 M e 2 Si Me 2-Cyclotrisiloxanol, 2,4,4,6,6-pentamethyl- Silacyclopentane 5 O 4 Si Me2 O3 ClSn M e 2 O Sn M e 2 Cl 1 23 H Si 10 O 9 1 11 O 2 H2 Si 3 Distannoxane, 1,3-dichloro1,1,3,3-tetramethylDiplumboxane, 1,3-dioxo-1,3-diphenylDisilaselenane, 1,1,1,3,3,3-hexamethylPlumbane, dimethyloxoDisilane, 1,1,1-trifluoroDiplumbane, 1,1,1,2,2,2-hexaethylPlumbane, hydroxyoxophenylDigermoxane, 1,3-dihydroxySilane, trimethoxymethylSilanol, 1,1,1-trimethyl-, 1-acetate O 7 O 5 4 Bicyclo[5.3.1]pentasiloxane Ph Pb ( O ) O Pb ( O ) Ph 1 23 H2Si O 8 Si H O 6 SiH 2 ( M e 3 Si) 2 Se Acyclic linear chains of tetravalent hydrides of silicon, germanium, tin, and lead are molecular skeletons with names derived from the mononuclear hydrides: Silane, SiH4; Germane, GeH4; Stannane, SnH4; Plumbane, PbH4. Examples: H3SiSiH3 H3GeGeH2GeH3 H3Sn(SnH2)11SnH3 H3SiSiH2SiH(SiH3)SiH2SiH3 Disilane Trigermane M e 2 Pb O F 3 SiSiH 3 12 E t 3 Pb Pb E t 3 1 2 Ph Pb ( O ) O H Tridecastannane Pentasilane, 3-silylHOGeH2OGeH2OH 1 23 When a single element of this series alternates with a single chalcogen in a linear acyclic chain, “-ane” names which express the nature of the alternating elements and number of silicon (etc.) atoms are employed. Examples: (H3Si)2O (H3Si)2S (H3Ge)2Se (H3Sn)2Te (H3SnO)2SnH2 H3Si(OSiH2)2OSiH3 Disiloxane Disilathiane Digermaselenane Distannatellurane Tristannoxane Tetrasiloxane ( M e O ) 3 SiM e M e 3 SiO A c CH 3 CH 3 O = Substituent prefixes (radicals) from silicon, germanium, tin, and lead mononuclear hydrides are formed by adding the suffixes “-yl,” “-ylene,” and “-ylidyne” to the appropriate stem, or “-tetrayl” to the hydride name: silyl, H3Si−; germylene, H2Ge=; stannylidyne, HSn≡ ; plumbanetetrayl, =Pb=. Radicals from polynuclear hydrides and “oxanes,” etc., are derived as for hydrocarbons. Examples: H 3 SiSiH 2 − −GeH2GeH2− 1 2 An acyclic chain of alternating silicon and nitrogen atoms is not named as a silazane; instead the functionality of the nitrogen is recognized. Thus, disilazane, H3SiNHSiH3, is indexed at Silanamine, N-silyl-. However, silazanyl radicals (see below) are employed in the presence of higher functions. Replacement (“a”) names are used as parents when the chain contains carbon atoms and the other requirements (¶ 127) are met. Example: MeO (C H 2 ) 2 O C H 2 SiMe 2 OSiMe 2 CH 2 O( CH 2 ) 2 OMe 1 2 5 7 89 11 14 15 − H 3 C − G e − O − C − CH 2 − CH 3 − Propanoic acid, trimethylgermyl ester disilanyl 1,2-digermanediyl (formerly digermanylene) tristannanylidene 1,2-distannanediylidyne 1-disiloxanyl 1-disilazanyl 1,3-diplumboxanediyl 1,3,5-trisiloxanetriyl H 3 Sn Sn H 2 Sn H = ≡ Sn Sn ≡ 1 2 2,5,8,11,14-Pentaoxa-7,9-disilapentadecane, 7,7,9,9-tetramethylDerivatives of all these parents are named by the usual substitutive methods except for silicic acids and germanium, tin, and lead hydroxides and salts (see below). A hydroxyl group on a germanium, tin, or lead atom is expressed as a hydroxy prefix, but by the suffix “-ol” on a silicon atom when it is a principal group. O-Acyl derivatives of silanols or of hydroxy germyl, stannyl, and plumbyl are named as esters. H 3 SiO SiH 2 − H 3 SiN H SiH 2 − − Pb H 2 O Pb H 2 − 1 23 − SiH 2 O SiH O SiH 2 − 1 3 5 − 67 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 CH 3 − CH 2− H2 H2 C−C N−C−S−C−N 1 4 CH 2 − CH 3 − CH 2 C−C H2 H2 S = S = ¶ 200 − F Me 3 SiO SiMe 2 C H 2 OH Methanol, 1-(1,1,3,3,3-pentamethyldisiloxanyl)- (not 3-Oxa-2,4-disilapentan-1-ol, 2,2,4,4-tetramethyl-) Benzenamine, 4-disilanyl- The additive term “sulfide” is used in modifications when sulfur is attached to saturated Group VA elements in molecular skeletons. The locant relating to the parent is used when the parent contains the heteroelement sulfide; otherwise, an element symbol provides the locant. Examples: 1 6 H2N SiH 2 SiH 3 O S 2 − The nonfunctional germanium, tin, and lead hydrides fall (in that order) between boron and oxygen heading parents in order of precedence of compound classes (¶ 106). The heading parent Silane is an exception. It now ranks below cyclic carbon parents and above acyclic carbon parents. This ranking does not apply to any other silicon parents, cyclic or acyclic, functional or nonfunctional. When a principal group is expressed as a suffix, the compound is classed accordingly. Silanol is ranked with the alcohols, and is placed above all carbon-chain monohydric alcohols, cyclic or acyclic (¶ 138). Examples: S = S = F − 1-Piperidinecarbodithioic acid, anhydrosulfide with N,N-diethylcarbamodithioic acid − − − F−P−S−S−P−F Thioperoxydiphosphoric tetrafluoride, ([F2P(S)]2S2) P O 3 OMe B z O S i H2CH2 OAc Silanol, 1-[[4-(acetyloxy)phenyl]methyl]-, 1-benzoate (not Phenol, 4-[[(benzoyloxy)silyl]methyl]]-, acetate) 1,3,2-Dioxaphosphorinane, 2-methoxy-, 2-sulfide = C H ( C O 2H)2 S = N Propanedioic acid, (1-sulfido-2pyridinyl)- E t 3 G eC H 2 (C H 2 ) 4 CH 2 NH 2 6 1 1-Hexanamine, 6-(triethylgermyl)Disiloxane, 1-(silylthio)- H 3 SiO SiH 2 S S iH 3 321 Oxides of doubly-bound sulfur atoms in principal groups are named in the modification with an “S” locant. Examples: M e C( = S = O ) N H 2 M e CH 2 C( = S = O ) CH 2 ( CH 2 ) 2 M e 1 3 4 7 Ethanethioamide, S-oxide 3-Heptanethione, S-oxide Silicic acids are silanes and siloxanes (and chalcogen analogs) in which all hydrogen atoms have been replaced by hydroxyl and oxo groups (or their chalcogen analogs). Their esters and anhydrides are named as usual. Cyclic derivatives are named as heterocycles. Examples: (E tO ) 4 Si Silicic acid (H4SiO4), tetraethyl ester Thiosilicic acid (H4SiO3S), O,O,O-tris(1-methylethyl) ester 1,4,6,9-Tetraoxa-5-silaspiro[4.4]nonane (not 1,2-Ethanediol, cyclic diester with silicic acid (H4SiO4)) (Me 2 C H O ) 3 SiS H 9 1 O O 6 O Si 5 O 4 Phosphine sulfide, Arsine sulfide, and Stibine sulfide (¶¶ 181, 197) are substitutive parent compounds, but the sulfides of Diphosphine, Triarsine, etc., are named by modification terms. Acyclic sulfides, sulfoxides, and sulfones, containing one or more isolated sulfur atoms, including thio acetals and thio ortho esters, are named (like ethers (¶ 196)) as substituents of hydrocarbons and other heading parents by use of thio radicals, unless a replacement (“a”) name (¶ 127) is permissible. In the latter, oxide terms in the modification are employed to express sulfinyl (−S(O)−) and sulfonyl (−S(O)2−) groups. The analogs of “thio” are “seleno” and “telluro”; those of “sulfinyl” are “seleninyl” and “tellurinyl”; those of “sulfonyl” are “selenonyl” and “telluronyl.” Examples: CH 3 − S − CH 2 − S − CH 2 − S − CH 2 − S − CH 3 1 2 3 4 5 6 7 8 9 Germanium, tin, and lead analogs of silicic acids are named at binary hydroxide and hydroxide oxide heading parents. Symmetrical derivatives of Germane, Stannane, and Plumbane, in which all hydrogen atoms have been replaced by groups derived from alcohols, thiols, etc., or acids, are named as metal salts. Examples: G e(O H ) 4 S nO (O H ) 2 Co 2 H • Pb 4 + 2,4,6,8-Tetrathianonane = = = = O 1 2 3 4 5 O 6 7 8 O 9 10 11 O 12 13 14 CH 3 − CH 2 − S − CH 2 − CH 2 − S − CH 2 − CH 2 − S − CH 2 − CH 2 − S − CH 2 − CH 3 Germanium hydroxide (Ge(OH)4) Tin hydroxide oxide (Sn(OH)2O) Benzoic acid, 4-methyl-, lead(4+) salt (4:1) M e Se CH 2 ( CH 2 ) 2 CO 2 H 4 1 3,6,9,12-Tetrathiatetradecane, 3,6,9,12-tetraoxide Butanoic acid, 4-(methylseleno)- 4Me 200. Sulfur, selenium, and tellurium compounds are often named similarly to oxygen compounds, but sometimes, e.g., in sulfonic and sulfenic acids (¶ 165), the sulfur, etc., acts as a nuclear atom in a functional group of which no oxygen analog is known. Because sulfur, selenium, and tellurium are treated identically, “thio,” “sulfur,” “sulfide,” etc., in the following discussion may invariably be replaced by the corresponding selenium or tellurium term. Cyclic sulfur compounds are named as heterocycles; sulfur alternating with silicon, germanium, tin, or lead atoms forms the silathianes, etc. (¶ 199). Sulfur analogs of anhydrides are usually named as anhydrosulfides, but the anhydrosulfides of acids named as functional parent compounds are often indexed at polynuclear acid headings, e.g., Thiodicarbonic acid. Examples: H3C − S = S = N − C − S − C − N− Ph CO CH 2 CH 2 T e Ph 1-Propanone, 1-phenyl-3(phenyltelluro)- H 2 N CH 2 CH 2 Se CH 2 CH 2 N H 2 1 2 2′ 1′ Ethanamine, 2,2 ′ -selenobis- = − O = O − H3C − CH 3 CH 3 Thiodicarbonic diamide, ([H2NC(S)]2S), N,N,N′,N′-tetramethyl- O CH 3 − CH 2 − T e − CH 3 = − CH3 O = CH3−CH2−S— C— S−CH2−CH3 = CH 3 O Propane, 2,2-bis(ethylsulfonyl)(principle: largest heading parent (¶ 138)) Ethane, (methyltellurinyl)- (principle: largest heading parent) ¶ 200 Me(C H 2 ) 6 S O 2 P h Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Benzene, (heptylsulfonyl)- (principle: ring preferred over chain) Benzene, [(cyclohexylselenonyl)methyl]- (principle: preferred ring system) 1′ 2′ 68 Cl( CH 2 ) 2 SSSCl FC( O ) SSCN Trisulfide, chloro 2-chloroethyl Disulfide, cyano fluorocarbonyl (not Formyl fluoride, (cyanodithio)-) P hC H 2 S e O 2 H 2 C = C H SC H 2 S CH = CH 2 2 1 Ethene, 1,1 ′ -[methylenebis(thio)]bis- (principles: largest heading parent and multiplication) Ethene, [(1-ethoxyethyl)thio](principle: maximum number of unsaturated bonds) Ethane, 1,1 ′ -thiobis[2-[(2,2-dichloroethyl)thio]- (principles: centrality and multiplication) H 2 C = C H SC H MeOEt The heading parents Disulfoxide, Trisulfone, etc., are employed for chalcogen compounds in which the same number of oxygen atoms is attached to each skeletal atom. When all oxide atoms are on one sulfur, the compounds are named whenever possible as esters or anhydrides of thio analogs of sulfur acids. When different numbers of oxide atoms are attached to skeletal sulfur atoms, substitutive nomenclature is employed in which thio, sulfinyl, and sulfonyl radicals are cited separately. Examples: [ M e S( O ) ] 2 C l 2 C H C H 2 S C H 2 C H 2 SCH 2 CH 2 SCH 2 CHCl 2 Disulfoxide, dimethyl Disulfone, bis(4-chlorophenyl) 2 6 Cl 1 SO 2 Cl SCH 2 OPh Cl Benzene, 2,4-dichloro-1-[(phenoxymethyl)thio]- (principle: maximum number of substituent prefixes) Benzene, [(2-phenylethyl)thio](not Benzene, [2-(phenylthio)ethyl]-) (principle: earliest index position) Ph SO 2 SPh Benzenesulfonothioic acid, S-phenyl ester SS( O ) S Cl Ph(C H 2 ) 2 S P h Cl PhC(O)SSH EtSSH (HO)2P(O)SSH HOSO2SSH Benzenecarbo(dithioperoxoic) acid Ethanesulfenothioic acid MeO SO 2 S( O ) = Hydrodisulfides are named as dithioperoxoic acids, as sulfenothioic acids, or as thio analogs of mononuclear peroxy “oxo” acids. The oxides R−S(O)−SH and R−S(O)2−SH are named as sulfinothioic and sulfonothioic acids. Examples: Thiosulfurous acid, (H2S3O), S,S-bis(4-chlorophenyl) ester S = O = S = HO−C−S−S−S−C−OH O Carbonodithioic acid, bis(anhydrosulfide) with thiosulfuric acid (H2S3O2) OMe Phosphoro(dithioperoxoic) acid Thioperoxymonosulfuric acid ((HO)(HSS)SO2) Benzene, 1-methoxy-4-[[(4-methoxyphenyl)sulfinyl]sulfonyl](not Benzene, 1-methoxy-4-[[(4methoxyphenyl)sulfonyl]sulfinyl]-) (principle: earliest index position) Cyclic sulfides, etc., are ranked according to the rules for ring systems; acyclic sulfur, selenium, and tellurium heading parents follow, in that order, the oxygen heading parents (Peroxide, etc.). Within each element group, the descending order is illustrated as follows: Trisulfide, Disulfone, Disulfoxide, Disulfide. In the presence of more preferred compound classes, dithio, trithio, diseleno, disulfonyl, etc., radicals are used as substituents. Examples: 1 1′ The compounds R−S−S−SH, R−S(O)−S−SH, R−S(O)2−S−SH, are named as sulfeno(dithioperoxoic) acids and their sulfino and sulfono analogs. Example: PhSSSH Benzenesulfeno(dithioperoxoic) acid Hydrotrisulfide is a radicofunctional heading parent for acyl derivatives, and Hydrotetrasulfide, etc., for alkyl and aryl derivatives. Example: EtSSSH Hydrotrisulfide, ethyl Acyl substituted polysulfides are named as Ketones 6 N SS N 6′ Pyridine, 3,3 ′ -dithiobis- AcSSSH Ethanone, 1-trithio- Cyclic polysulfides are named as heterocycles; acyclic sulfides fulfilling the requirements (¶ 127) of replacement nomenclature are indexed at “thia” names. Other acyclic disulfides, trisulfides, etc., are indexed at Disulfide and similar heading parents unless they are esters of dithioperoxoic acids or chalcogen analogs of peroxy condensed mononuclear acids. (Examples of these exceptions are illustrated below.) Hydrogen polysulfides in which both of the terminal hydrogen atoms have been replaced by sulfo groups constitute the polythionic acids; thus, Tetrathionic acid is HO3S−S−S−SO3H. Examples: MeCH 2 S(CH 2 ) 2 OSSO(CH 2 ) 2 SCH 2 Me 1 3 678 9 12 14 S SSPh Thiophene, 3-(phenyldithio)(principle: preferred ring system) H O 3 S CH 2 CH 2 SS( O ) ( CH 2 ) 2 SO 3 H 1 2 6,9-Dioxa-3,7,8,12-tetrathiatetradecane Disulfide, bis(1-methylethyl) Diselenide, bis(phenylmethyl) Disulfide, 1,1′-(1,2-ethanediyl)bis[2ethyl Trisulfide, diphenyl Ethanone, 1,1′-dithiobisTriselenide, bis(diethylphosphinoselenoyl) Disulfide, diethoxy H O SO 2 SS M e Ph SO 2 SSPh Ethanesulfonic acid, 2-[[(2sulfoethyl)sulfinyl]thio]- (not Ethanesulfonic acid, 2-[[(2-sulfoethyl]thio]sulfinyl]- (principle: earliest index position) Me 2 C H S S C H Me 2 P hC H 2 SeSeC H 2 Ph (E tS S C H 2 ) 2 Acyl alkyl and acyl aryl disulfides are named as esters of either dithioperoxoic acids or peroxy mononuclear “oxo” acids. Examples: O = CH 3 − C − S − S − CH 3 P hS S S P h A cS S A c [E t 2 P(Se)S e] 2 Se E tO S S O E t A cS S C l Ethane(dithioperoxoic) acid, methyl ester Benzenesulfono(dithioperoxoic) acid, phenyl ester Thioperoxymonosulfuric acid, ((HO)(HSS)SO2), SS-methyl ester Ethanone, 1-(chlorodithio)- 69 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 201 Symmetrical diacyl disulfides derived from polybasic mononuclear “oxo” acids (except Sulfuric acid and Sulfurous acid; see above) are named at Thioperoxy headings. Example: = = S S Mixed sulfide-selenides, etc., with three contiguous chalcogen atoms are usually named by compound and complex radicals; e.g., [selenobis(thio)] for −S−Se−S−. When only two different contiguous chalcogen atoms are present, the compound is an ester of a sulfenic (etc.) acid analog. Example: PhSSePh Benzenesulfenoselenoic acid, phenyl ester H O − C H 2 − C H 2 − N H − C − S − S − C − NH − CH 2 − CH 2 − OH Thioperoxydicarbonic diamide, ([(H2N)C(S)]2S2), N,N ′ -bis(2hydroxyethyl)Sulfilimine, H2S=NH, and Sulfoximine, H2S(O)=NH, are substitutive heading parents. The selenium and tellurium analogs are named Selenilimine, Tellurilimine, Selenoximine and Telluroximine. They are ranked just below imine suffix compounds (¶ 106). Higher functions in chalcogen-linked derivatives can be recognized by use of other chalcogen-nitrogen parents or by sulfonimidoyl, sulfinimidoyl, etc., radicals. Examples: Et2S=NH Acyclic tetravalent and hexavalent sulfur compounds containing at least one substituent derived from a molecular skeleton (¶ 130) that cannot be named by general index nomenclature as described above, or as “oxo” acid derivatives, are given coordination names (¶ 215). Examples: PhSF5 Ph2TeCl2 Sulfur, pentafluorophenyl-, (OC-6-21)Tellurium, dichlorodiphenyl-, (T-4)- Sulfilimine, S,S-diethyl4 2 1 MeS (O ) (= N H )C H 2 CH 2 CH( NH 2 ) CO 2 H Butanoic acid, 2-amino-4-(Smethylsulfonimidoyl)N-derivatives containing higher chemical functions are named at these functions by using the following newly introduced radical names: λ4-sulfanylidene, λ6-sulfanylidene and their selenium and tellurium analogs Et2S=NSO2Ph 201. Zwitterionic compounds have internally compensating ionic centers. When the cationic center is known, the compound is named either as an “inner salt”. M e 3 N + CH 2 − Methanaminium, N,N,N-trimethyl-, inner salt Sulfonium, dimethyl(2-oxo-2-phenylethyl)-, inner salt Pyridinium, 1-[2-ethoxy-1-(ethoxycarbonyl)2-oxoethyl)-, inner salt Phosphorane, triphenyl(phenylmethylene)(preferred index name) Ph CO C − H S + M e 2 Benzenesulfonamide, N-(diethylλ4-sulfanylidene)Urea, N-butyl-N′-[methyl(4-methylphenyl)oxide-λ4-sulfanylidene]Benzenesulfinimidic acid, N-phenylImidosulfurous acid, N-phenyldimethyl ester N + C − ( CO 2 E t) 2 Me S(O)Me = NCONHBu Ph 3 P = CH Ph PhS (O H ) = N Ph (MeO ) 2 S = N P h Sulfur diimide, HN=S=NH, and Sulfur triimide, HN=S(=NH)=NH, are substitutive heading parents and are ranked with the sulfur parents. The above mentioned radical names are used when higher functions are present. Examples: HO2C N=S=N CO 2 H Zwitterionic compounds are usually named at the “-ium” heading with “inner salt” as the phrase in the modification. “Inner salt” (¶ 293A) indicates a compensating anion located in the same molecule as the cation. The expression “bis(inner salt)” at a “-diium” heading indicates two compensating anions in the same molecule. A phosphonium compound of this type is indexed as a phosphonium inner salt only when such a zwitterionic structure is emphasized or discussed by the author. Otherwise only a neutral Phosphorane entry is made. Examples: M e 3 N + CH 2 CO 2 − N 1 Methanaminium, 1-carboxy-N,N,Ntrimethyl-, inner salt Benzenaminium, 3-[(hydroxymethoxyphosphinyl)oxy]-N,N,Ntrimethyl-, inner salt Benzoic acid, 4,4-(λ4-sulfanediylidenedinitrilo)bis(C H 3 ) 3 S i − N = S = N− Si( CH 3 ) 3 = N Si(CH 3 ) 3 + Me3N O P( O ) O M e O− Silanamine, N,N′,N′′-λ6-sulfanetriylidenetris[1,1,1-trimethylAcN− N + Sulfimide, O2S=NH, and Thionyl imide, OS=NH, are substitutive heading parents. They follow the imines in order of precedence (¶ 106) and, when necessary, are expressed by sulfonyl (O2S=) (sulfinylamino) (OS=N−), etc., radicals. Examples: O2S=NMe PhSO2N=SO Methanamine, N-sulfonyl- Quinolinium, 1-(acetylamino)-, inner salt O 1 6 Benzenesulfonamide, N-sulfinylHO PPh 3 2,4-Cyclohexadien-1-one, 4hydroxy-6-(triphenylphosphoranylidene)- (the alternative ionic structure is named Phosphonium, (2,5-dihydroxyphenyl)triphenyl-, inner salt) Hydrazinium, 1-[(4-methylphenyl)methylidyne]-2-phenyl-, inner salt Amidosulfenyl chloride (H2N−S−Cl) is ranked with mononuclear “oxo” acid halides and can be expressed by (chlorothio) and [(chlorothio)amino] radicals when necessary. Example: PhSO2NMeSCl Amidosulfenyl chloride, N-methylN-(phenylsulfonyl)- (not Benzenesulfonamide, N-(chlorothio)-Nmethyl-) Me +− C ≡ N − N Ph Cationic “ium” compounds with internally compensating borate anions are named where possible by coordination nomenclature (¶ 215); the term “borata” is avoided. ¶ 201 Example: Cl N N − − Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 1 − 1 5 70 Cl B 3+ 3+ B N N − − Boron, tetrachlorobis[µ-(1Hpyrazolato-κN 1 :κN 2 )]di- (not 4H,4H,8H,8H-7a,8a-Diaza-3a,4adiazonia-4,8-diborata-s-indacene, 4,4,8,8-tetrachloro-) HN 5 O + − 3 HN N 2 O 2 N N+Me 3 N+Me Cl − Cl − 1,2,3-Oxadiazolium, 5-amino-3methyl-, inner salt (formerly Sydnone imine, 3-methyl-) Meso-ionic compounds such as sydnone derivatives are named, if possible, at an “-ium” parent by use of the term “inner salt” in the modification. Examples: mesoionic form 1 preferred structure 1 O 10 a 1 O + − 10 b 2 2 3 O− 10 a 1 O + 10 b 2 3 N N O 5 O + − HO N 3 2 5 O N4 N4 N N + CHM e 2 O C O− 3 7 6 7 6 N C H Me 2 HO2C [1,2,3]Oxadiazolo[4,3-a]isoquinolin4-ium, 5,6-dihydro-1-hydroxy-, inner salt 1,2,3-Oxadiazolium, 4-carboxy-5hydroxy-3-(1-methylethyl)-, inner salt (formerly Sydnone, 4-carboxy-3-(1-methylethyl)- 71 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 E. STEREOCHEMISTRY AND STEREOPARENTS ¶ 203 Introduction Stereochemistry Alkaloids Amino acids Peptides Proteins ¶ 202 203 204 205 206 207 Carbohydrates Cyclitols Nucleosides and Nucleotides Steroids Terpenes ¶ 208 209 210 211 212 202. Introduction. A discussion of stereochemical descriptors for systematically named compounds, modified stereoparents, and coordination compounds follows this introduction. The remainder of Section E is directed to various classes of stereoparents. A stereoparent is an index heading parent the name of which implies specific stereochemical information. Illustrative structural diagrams for stereoparents that have received entries in current indexing are provided in the Chemical Substance Index; these diagrams indicate both the stereochemistry and the numbering systems from which locants are derived. The bond lengths and angles shown in these diagrams have been drawn in a standard format and do not necessarily represent the actual shape of the compounds. It is convenient to divide natural products into four classes according to the methods by which they are indexed. The classification has been most completely worked out for alkaloids, discussed more fully in ¶ 204, below. Class A contains those substances, of little or no stereochemical complexity, which are indexed systematically rather than at stereoparents. Class B stereoparents represent groups of natural products which have cyclic molecular skeletons in common. The base structure is derived by removal of all chemical functions but retention of hydrocarbon substituents and the pattern of hydrogenation; the name is derived from the trivial names of the related natural products, and author numbering is adopted if possible. General substitutive nomenclature, as illustrated in previous sections of this introduction, is used to convert the stereoparents into complete index names by addition of prefixes, suffixes and conjunctive terms. Examples of Class B stereoparents are Prostane and Picrasane: Example: L- Proline, compd. with (8α,9R)-cinchonan-9-ol (1:1) Acyclic acetals of functions expressed by “-one” suffixes or “oxo” substituents of stereoparents are indexed as dialkoxy derivatives. Cyclic acetals of stereoparent diols with formaldehyde are named as [methylenebis(oxy)] derivatives of the stereoparent; other cyclic acetals are named similarly if subsidiary functions of the stereoparent are involved, but by modification terms if a principal chemical function has been acetalized. Lactones of principal functions are also named in the modification. Examples: 21 CH2OH 18 Me 20 Me CO O 19 1 O Me 9 10 11 H 13 14 17 Me O H 6 8 H Pregnane- 3,11,20- trione, 21hydroxy -16,17- [(1- methylethylidene)bis(oxy)]-, (5α,16α)- O 4 H 18 Me 9 OH 17 H 7 1 11 Me Me 20 11 Prostane ((1S,2 S)- 1- heptyl- 2octylcyclopentane) 19 Me 1 9 H 13 14 O O 10 3 4 H 6 8 Androst-5-en-3-one, 17-hydroxy-, cyclic 1,2-ethanediyl acetal, (17β)- H H 13 21 19 1 11 9 Me Me 8 7 20 Me 13 14 4 10 5 H 6 H O 17 Picrasane ((3S,3aS,6aR,7aS,8R,11aS, 11bR,11cS)-hexadecahydro 3,8,11a,11c-tetramethylphenant hro[10,1-bc]pyran) 18 Me H H Class C stereoparents imply both stereochemistry and chemical functionality. Other functions (including higher functions) are expressed as substituents. Examples will be found in the discussion of alkaloids (¶ 204). Miscellaneous Class C stereoparents include Leucomycin V. Their derivatives are indexed like alkaloids. Class D stereoparents possess incompletely elucidated structures. If sufficient information is available, they are named systematically and no stereochemical descriptor is assigned. When no systematic name is possible, the trivial name in the original document is used. Because treatment of stereoparents by the general rules of substitutive nomenclature can sometimes lead to loss of stereochemical information, special rules for their derivatives are employed. Thus, esters and semicarbazones (and their chalcogen analogs) are named as derivatives of the stereoparents, not at “Class II” acid names or as Hydrazinecarboxamide derivatives. Esters formed by an acidic and an alcoholic stereoparent are indexed at the stereoparent that contains the highest chemical function. Examples: Androstan-17-ol, butanoate, (5α,17β)The preferred CA name is the one that employs the stereoparent in the index heading parent. Addition compounds and salts containing more than one stereoparent derivative are assigned a preferred index name based on chemical functionality of the stereoparents. When two or more stereoparents are covalently attached to one another the compound is normally indexed at the stereoparent that expresses (a) the largest number of highest chemical functions, (b) the most preferred skeleton. Citation of additional and modified stereochemistry at stereoparent and stereoparent derivative names is discussed in the following section. 203. Stereochemistry is expressed in CA index names1 by three methods: The stereochemistry for the heading parent of systematically named compounds, including some natural products with only one or two chiral centers, e.g., most carbohydrates with four or fewer carbon atoms, simple alkaloids and terpenes, and some steroid degradation products, is expressed in the modification, following all other structural information such as “ethyl ester,” and ahead of descriptive terms related to a specific abstract, such as “spectrum of.” Additional stereochemical expressions are included with the substituent and modification terms to which they refer. The terms used in this “systematic stereochemistry” are the main subject of the present section. Natural products, especially those with a multiplicity of chiral centers, are conveniently indexed at fundamental trivial names (stereoparents) where they and their derivatives can be found at headings familiar to users in the alkaloid, carbohydrate, steroid, and terpene fields. The concept of stereoparents has been discussed above; the separate natural product classes to which it is applied are the subjects of ¶¶ 204-212. Coordination compounds require specialized descriptors to describe the arrangement of ligands around the central atom. These are discussed in the final part of this paragraph. I. Systematically named compounds. New rules have been adopted for systematic stereochemistry in CAS index nomenclature. These conventions have been applied since March 1997 to systematically named fragments of structures containing stereoparents. The new policy was expanded in June 1For a more extensive discussion of the stereochemical descriptors found in CA index names, see J. E. Blackwood and P. M. Giles, Jr., J. Chem. Inf. Comput. Sci. 1975, 15, 67-72; M. F. Brown, B. R. Cook, and T. E. Sloan, Inorg. Chem. 1975, 14, 1273-1278; ibid. 1978, 17, 1563-1568. ¶ 203 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 72 1998 (CA Volume 129) to all systematic organic compounds. The methods described below are a simplification of previous CAS stereochemical practice. Rules that were in use since the beginning of the Ninth Collective Index period (1972) have now been thoroughly revised. The need for a single expression to describe the total stereochemistry of a molecule has been eliminated. Stereochemical terms are now placed within the parts of a chemical name to which the stereochemical information applies. Only the stereochemistry contained in the heading parent is expressed in the name modification following all other structural information. In general, the new rules are consistent with IUPAC recommendations and produce CAS index names containing stereochemical information which can be readily interpreted. The terms R and S are employed for chiral elements possessing either absolute or relative stereochemistry. The term rel is used in conjunction with R and S for structures with only relative stereochemistry. E and Z are used primarily to describe geometrical isomerism about double bonds. The relative terms cis, trans, endo, exo, syn, anti, α, and β are used as alternatives to R and S in certain limited situations. Assignment of the absolute terms R and S depends on the priority ranking of atoms or groups attached to the stereochemical element whose chirality (“handedness”) is to be determined by the Cahn-Ingold-Prelog Sequence Rule.2,3 This ranking depends first on the descending order of atomic number of the atoms directly attached to the chiral center; thus, for bromochlorofluoroiodomethane the order is I, Br, Cl, F. In the following diagrams these atoms are represented by a, b, c, and d, respectively. The least preferred atom or group, d, is represented by a dotted line to indicate it is to be considered to be below the plane of the paper, while a, b, and c are to be imagined to project toward the viewer at an angle. (The analogy of an automobile steering wheel with three radial bars is a useful one to visualize.) R is assigned to a clockwise (right-handed) sequence of a, b, c, while S denotes a counterclockwise (anticlockwise) sequence. The following groups are arranged in descending order of Sequence Rule priority: -SCH3, -SH, -OCOCH3, -OCH2CH3, -OCH3, -OH, -NO2, -N(CH3)2, -NH2, -COOH, -COCH3, -CHO, -CH2OH, -C≡N, -CH2NH2, -C(CH3)2CH2CH3, -C(CH3)=CH2, -CH(CH3)CH2CH3, -C6H5, -CH2CH2CH3, -CH2CH3, -CH3. It is essential to rank branched chains by a rigorous procedure if assignment errors are to be avoided. In HO CH H3C- CH | CH3 CH3 C H OCH3 CH CH2CH3 c ≡ b C d a a d c R b b a d c S Alternative ways of drawing chiral diagrams are often more convenient: either (a) at most two bonds (as indicated by ordinary lines) are shown to be in the plane while one projects forward and one backward (as indicated by a wedge and a dotted line, respectively), or (b) two bonds are shown projecting forward and two backward, as in the diagram below. In both instances it must be remembered that the atom or group of lowest priority, d, must be oriented away from the viewer so that the clockwise or counterclockwise arrangement of a, b, and c is correctly observed. In organic compounds it is generally necessary to compare the ranking of two or more carbon bonds. This is done by proceeding outward one step at a time until a decision is reached. a it can be immediately perceived that H has the lowest rank (d) and that of the three carbon bonds CH3 has rank c. Proceeding outward to the left and right from the chiral enter we observe that each carbon is attached to one oxygen, one carbon, and one hydrogen. The rule to be observed here is that we should now proceed just one step along the senior (highest-priority) branches (in this instance through the oxygens) to find H on the left, C (preferred) on the right. The fact that, in the junior branch, the priorities are reversed, with C attached to two C’s and an H on the left, to only one C and two H’s on the right, is disregarded, because this stage in the process is never reached. Only when a one-step search of the senior branches results in a tie is the junior branch inspected to the same extent. (This would have been necessary, with a consequent assignment of S instead of R, if -OCH3 replaced -OH in the diagram, even if, at the same time, -OCH2CH3 replaced -OCH3 on the right.) In complicated cases it is sometimes necessary to construct an exploration table or tree diagram in assigning R and S descriptors. A useful summary of Sequence Rule procedures is included in Section E of the IUPAC rules,2 but consultation of the papers of Cahn, Ingold and Prelog, especially their 1966 paper,3 may be necessary for resolution of the most difficult cases. Relative descriptors of various kinds are used as follows: (A) cis and trans are restricted to cyclic structures with two achiral stereogenic atoms (an atom is stereogenic when interchange of two of the atoms or groups attached to it produces a nonidentical compound). An example is 1,3Cyclobutanediol. The cis isomer has the senior groups (as defined by the Sequence Rule) on the same side of the reference plane. (B) endo and exo are used only for achiral ring positions on the X and Y bridges of bicyclo[X.Y.Z]anes (¶ 155) in which X ≥ Y > Z > 0, and X + Y < 7. The exo isomer has the configuration in which the senior substituent is on the same side of the reference plane as the Z bridge (see diagram below). (C) syn and anti are restricted to achiral ring positions on the Z bridge of a bicyclo[X.Y.Z]ane in which X ≥ Y > Z > 0, and X + Y < 7. The syn isomer has the senior substituent oriented towards the X bridge. anti Y Z syn exo X endo CH2 Cl c H3 C reference plane C H d CH2 OH b In the structure above, H clearly has the lowest priority, but it is necessary to establish the ranking of the three carbon groups. This is done by arranging the atomic numbers of the most senior substituent on each carbon in descending order: Cl, O, H. This elicits the absolute stereochemical descriptor R. Branching, especially branching close to the chiral center, raises the priority ranking of alkyl groups. Multiple bonds of all kinds are handled by “duplicating” or “triplicating” both of the atoms connected by the bonds; thus: (D) α and β are employed for ring positions of certain meso cyclic compounds. In the diagram below, the senior groups at the three stereogenic centers (by the Sequence Rule) are a, c, e; the junior groups are b, d, f. The α-side of the reference plane is that side on which the preferred substituent lies at the lowest-numbered stereogenic position; c lies on the same side as a, so both are assigned α descriptors; e lies on the opposite side of the reference plane and is assigned a β descriptor; hence: 1α, 2α, 4β. It should be noted that this usage differs from that for cyclic stereoparents (¶ 203II, below), in which “α-” means “below the plane” and denotes absolute configuration. α-side f 4 C a 1 — HC = CH — ≡ H H — C — C— | | (C) (C) — CH = O ≡ H —C—O | | (O) (C) e 3 2 b senior groups d β-side Only the immediate atoms are replicated; the procedure is not carried further. Aryl, e.g., phenyl, naphthalenyl, radicals are handled in a similar manner. (E) E and Z (from German: “entgegen” (opposite) and “zusammen” (together)) are geometrical stereodescriptors for substances having achiral elements resulting from double bonds. In a compound a c X=Y b d Union of Pure and Applied Chemistry. Nomenclature of Organic Chemistry, Section, A, B, C, D, E, F and H, 1979 ed., Pergamon Press, Oxford (England) 1979, Section E, Appendix 2, pp. 486-490. 3R. S. Cahn, C. K. Ingold, and V. Prelog, Angew. Chem., Int. Ed. Engl. 1966, 5, 385-415 (errata: 1966, 5, 511). For a modification in the treatment of cyclic pathways, see V. Prelog and G. Helmchen, ibid. 1982, 21, 567-583. 2International the double bond can be considered to be in a vertical plane, and a, b, c, and d in a horizontal plane. When the senior atom or group at X (a) and the senior 73 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 C11H23NO3 Stereo: absolute (-) ¶ 203 atom or group at Y (c) are on the same side of the vertical reference plane, the descriptor Z is cited; its isomer is assigned an E descriptor.4 (G) The (±) descriptor is only used for indicating stereoparents are racemic instead of absolute. The optical rotation descriptors (+) and (-) indicate the sign of rotation of plane-polarized light in the visible range (400-700 nm). The original literature should be consulted for the specific conditions under which the optical rotation was obtained. These descriptors, alone or in combination, are employed to express the total stereochemical information for a chemical substance as follows: (1) Stereochemistry for the index heading parent is cited at the end of the preferred (inverted) index name. Locants are used with all stereochemical terms, except cis and trans, relating to the parent. (2) Stereochemistry for substituents and modifications of the parent are expressed at the beginning of each individual nomenclature fragment to which the stereochemical terms apply. (3) The preferred stereo terms are R, S, E, and Z. Each is preceded by a locant, arranged in locant order, and separated by commas. The resulting stereochemical expression is enclosed in curves and followed by a hyphen, e.g., (1R,2S,3R,5E)-. (4) For substances with only partially known stereochemistry, stereogenic elements of unknown configuration are ignored for nomenclature purposes. The term [partial] is no longer used. (5) The term rel is used as a global expression to denote that the entire stereochemistry of a structure is relative only. Thus, rel appears at the end of the name modification following any stereochemical terms describing the parent. (6) The sign of optical rotation, (+) or (-), follows the term rel when the complete relative configuration of a substance is defined but the absolute stereochemistry is unknown. (7) When the substance has only one chiral element, not defined by the author, the sign of rotation is cited alone at the end of the inverted name. (8) In the uninverted name (+), (-), rel, rel-(+), or rel-(-) appear at the beginning of the name, before any other terms. (9) When the absolute configuration of a substance is unknown, either of two enantiomeric structures may be used to depict the relative configuration. Both the inverted and uninverted names will express that enantiomer which results in the first occurring R term in the inverted CAS index name. (10) Stereogenic centers which cannot be expressed as R or S may be described using endo, exo, syn, anti, cis, trans, α, or β. (11) Bicyclo[X.Y.Z]ane compounds in which X≥Y>Ζ>Ø, and X+Y<7, and which contain achiral stereogenic elements are the only structures for which endo, exo, syn, and anti are used. These terms are each preceded by a locant which is followed by a hyphen with the resulting stereochemical expression enclosed in curves, e.g., (3-endo, 8-anti). (12) The terms cis and trans are used for eight-membered or smaller rings substituted in only two achiral stereogenic positions. No locants or enclosing marks are used with single occurrences of these terms. Multiple terms for ring assemblies, e.g., bicyclohexyl, are cited in the order of unprimed, primed, double-primed, etc., rings and separated by commas and enclosed in curves. (13) Use of α and β is restricted to cases not covered by the above rules. These terms are not cited in the same stereochemical expression in combination with other relative terms. Examples: C7H13NO2 Stereo: absolute H N S CO OMe Me H OH | N S S OH R OH 2,3-Piperidinediol, 2-[(5R)-5-hydroxyhexyl]-, (2S,3S)C8H11C10 Stereo: relative S Cl S H S OH R Tricyclo[,4]octan-2-ol, 5-chloro-, (1R,2S,4R,5R)-relC19H30O3 Stereo: absolute partial E H X RO H R S OH E OH X X Me Me 3-Pentene-1,2-diol, 1-[(2R,7aR)-3a-(2E,4E)-2,4-hexadinenyloctahydro-2benzofuranyl]-, (1S)C11H15Br Stereo: relative CH2 Br E Z Cyclohexene, 1-[(1Z, 3E)-5-bromo-1,3-pentadienyl]C9H14O4 Stereo: absolute OH 2-Piperidinecarboxylic acid, methyl ester, (2S)O C10H18O2 Stereo: relative OH S R Me O RH S E CO OEt 2-Pentenoic acid, 5-hydroxy-5-(2R)-2-oxiranyl-, (2E,5S)C14H20I2O2 Stereo: relative (+) O R Z Me R CO E CHI2 1-Oxaspiro[5.5]undecan-7-ol, (6R,7S)-rel- E. Blackwood, C. L. Gladys, A. E. Petrarca, W. H. Powell, and J. E. Rush, “Unique and Unambiguous Specifications of Stereoisomerism about a Double Bond in Nomenclature and Other Notation Systems”, J. Chem. Doc. 1968, 8, 30 -32. 4J. 2-Butenoic acid, 4,4-diiodo-, (1R,3R,5Z)-3-methyl-5propylidenecyclohexyl ester, (2E)-rel-(+)(The Z double bond is cited on the atom closer to the parent.) ¶ 203 C14H22O2 Stereo: absolute Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 C12H14O4 Stereo: relative O Me O R S S H Me S R Me O O H 74 CO2 H Spiro[5H-indene-5,2´-[2H]pyran]-1(4H)-one, decahydro-7a-methyl-, (2´R,3aS,7aS)(The lower locant (2´ ) is used to cite the R center.) C8H11BrO Stereo: absolute Benzoic acid, 4-[(2α,4β,5β)-4,5-dimethyl-1,3-dioxolan-2-yl](The 2-position on the dioxolane ring is achiral stereogenic.) Me The stereochemistry of some compounds cannot be described completely by the rules above. The presence of stereochemical information in an original document is indicated in the index entries for such compounds by the modification term “stereoisomer.” Examples: OH S S O R R Br stereoisomer [This achiral stereogenic system can only be described by syn or anti, but these descriptors are not allowed for this ring system.] Bicyclo[2.2.1]heptan-2-one, 3-bromo-7-methyl-, (1S,3R,4R,7S)C16H20O3 Stereo: absolute HO stereoisomer S R OH [This achiral stereogenic system can only be described by the α / β system, which is not allowed in rings of this size. Had the system been chiral, R and S could have been used.] O CO Ph Molecular addition compounds, mixtures and polymers of components with stereogenic elements have the stereochemical descriptors cited with the respective components; a descriptor for the entire addition compound, etc., is cited last, if known. Examples: Cyclohexanol, 4-aminotrans-, acetate (1:1) 2-Furancarboxylic acid, tetrahydro-2-methoxy(2R)-, compd. with rel-methyl (1R,2S)2-aminocyclobutanecarboxylate 1,2-Cyclobutanedicarbonyl dichloride (1R,2R)-rel-, polymer with rel-(2R,5S)-2,5-dimethylpiperazine Although the polymer in the final example above probably has cis-trans stereochemistry, these terms are not repeated at the monomer headings; the structural repeating unit entry (¶ 222), however, would cite the descriptors in the order dictated by that heading. II. Stereoparents have been discussed in ¶ 202. A stereochemical descriptor is cited in an index modification at a stereoparent heading to express differences between the stereoparent illustrative diagram and the structure of the reported substance. In the diagrams the configurations on ring-system substituents are indicated by dotted lines for α and “wedges” for β. Variations for specific derivatives are indicated by citing appropriate α and β terms with the locants of the modified centers. Variant stereochemistry for acyclic, bridge and spiro centers is indicated by E and Z or by R and S as described for systematic stereochemistry, above. If a variation is not reported, the normal stereochemistry is considered to be retained. When the modified stereochemistry is unknown, e.g., indicated by a wavy line in a structural diagram, the descriptor x (xi) is assigned to that position. Descriptors are also cited for added configurations (when the stereoparent diagram shows no stereochemistry at a center). When the added stereochemistry is in a stereoparent substituent or modification, the descriptor is cited as a prefix, e.g., [(5α,16E)-androstan-16-ylidene]-. When the center is in a systematically named substituent or modification term, the descriptor is placed with the systematic nomenclature term, e.g., Pregnane -3, 20 - dione, 5 - hydroxy - 6[(1Z) -3 -hydroxy -1-propenyl]-, (5α,6β)-. Examples (the stereoparent diagram is compared with an author’s diagram for a derivative in each case): S OH Benzeneacetic acid, α-hydroxy-, (3-endo)bicyclo[3.2.1]oct-3-yl ester, (αS)C21H36O4 Stereo: relative Et OH H CO H O H OH [1, 1´-Bicyclohexyl]-4-carboxylic acid, 4´-ethyl-1-hydroxy-, trans-4-hydroxycyclohexyl ester, (cis,trans)(The unprimed ring is cis and the primed ring is trans.) C12H14O4 Stereo: absolute CO2 H Me S S Me O O H Benzoic acid, 4-[(4S,5S)-4,5-dimethyl-1,3-dioxolan-2-yl](The 2-position on the dioxolane ring is non-stereogenic.) 75 O CH3 H3C H Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 CH 3 H 19 1 21Me 20 CH 2 18 Me ¶ 203 C are not required for 4-and 6-coordinate anionic coordination complexes containing nonmetallic central atoms and identical monodentate ligands: they can be assumed to be tetrahedral and octahedral, respectively. The terms are omitted also when information is lacking. T-4 SP-4 TB-5 SP-5 OC-6 TP-6 PB-7 OCF-7 TPS-7 CU-8 SA-8 DD-8 HB-8 OCT-8 TPT-8 TPS-8 TPS-9 HB-9 tetrahedral square planar trigonal bipyramidal square pyramidal octahedral trigonal prismatic pentagonal bipyramidal octahedral faced monocapped trigonal prismatic square faced monocapped cubic square antiprismatic dodecahedral hexagonal bipyramidal octahedral trans-bicapped trigonal prismatic triangular faced bicapped trigonal prismatic square faced bicapped trigonal prismatic square faced tricapped heptagonal bipyramidal H H O H 4 A pregnane derivative (The configuration at positions 8, 9, 10, 13 and 14 correspond; position 5 has added stereochemistry; position 17 has modified stereochemistry. The stereochemical descriptor at Pregn-6-ene-3,20-dione is (5α,17α)-.) H CH3 H3C H OH H H O HO OH 4 = Me 9 10 11 H 13 8 17 14 H 6 H Pregnane (stereoparent) H CH2OH OH 1 19 18 O Me 9 10 Me 11H 13 8 14 17 H 6 H HO2CCH2 An androstane derivative Androstane (stereoparent) Positions 8, 9, and 13 are normal; position 14 is substituted, but has normal configuration. Position 10 has unknown modified stereochemistry; positions 3, 5 and 16 have added stereochemistry and the substituent at 16 is a stereoparent (β-D-glucopyranosyl radical). The stereochemical descriptor is (3β,5α,10ξ,16β)-. (The stereochemistry within the stereoparent radical is expressed by the substituent radical name.) III. Coordination compounds. The stereochemistry of mononuclear complexes is expressed by special descriptors. The term “stereoisomer” is used for polynuclear coordination complexes when all the nuclear stereochemistry is known. When no nuclear stereochemistry is known, ligand stereochemistry is cited using the rules for systematic organic compounds. No ligand stereochemistry is cited unless all ligand stereochemistry is described. When more than one ligand is stereogenic, the stereochemistry for the complex is cited as if all ligand stereochemistry is in one organic ligand. The discussion that follows is necessarily brief; for a more detailed explanation the review by T. E. Sloan5 should be consulted. For coordination numbers 1, 2, and 3, no nuclear stereochemistry is possible. Ligands are assigned systematic descriptors according to the rules in I above. If the chirality of a 3-coordinate tetrahedral complex is reported, it is described as R or S by application of the Sequence Rule as described above. The special coordination descriptors comprise: (a) a symmetry site term to describe the molecular geometry about the nuclear atom; (b) a configuration number to identify the atoms on each axis and plane of the system; (c) a chirality symbol to differentiate members of enantiomeric pairs (when the structure has no reflection symmetry); and (d) a ligand segment (when ligands have stereochemistry of their own) cited as described in ¶ 203I, above. Symmetry site terms are comprised of one- to three-letter abbreviations to describe the geometry around the central atom combined with the coordination number. They are generally based on information reported by an author, but some assumptions are made in indexing: square planar for 4-coordinate Pd2+, Pt2+, Rh+, Ir+, Au3+, Se2+, and Te2+; square pyramidal for 5-coordinate nitrido complexes of all metals and oxo complexes of technetium (the nitrido and oxo ligands are assumed to be axial); octahedral for all 6-coordinate complexes unless the ligand constraints prohibit this geometry; or if an anionic nonmetallic coordination center contains six identical monodentate ligands; tetrahedral for 4-coordinate complexes of (a) all 4-coordinate metallic complexes except Mn, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, or Au; (b) any 4-coordinate complex of Fe2 -, Ru2 -, Os2 -, Co-, Rh-, Ir-, Ni0, Pd0, Pt0, Cu+, Ag+, or Au+; (c) Ni2+, Fe2+, Fe3+, or Mn2+ with four halides or pseudohalides; (d) Co2+ with four monodentate ligands; (e) all 4-coordinate nonmetallic complexes except Se2+ and Te2+ (tetrahedral descriptors are not cited for anionic nonmetallic complexes containing four identical monodentate ligands); and (f) substances indexed at Antimony(1+), Arsenic(1+), Bismuth(1+), and Phosphorus(1+) (not Phosphonium, see ¶ 184). Americyl, neptunyl, plutonyl, and uranyl (Mo2n+) groups in 5, 6, 7, 8, and 9 coordinate complexes are assumed to be trans. Molybdenyl and tungstyl are assumed to have cis oxo groups. The ammines are assumed to be trans in the Reineckate anion. Planar ring systems, α-dioximes, 2,2´:6´,2´´-terpyridine and 2,2´,2´´- nitrilotris[ethanol] as ligands impose their geometry on the central atom; thus, a zinc-porphine complex is square planar, not tetrahedral. Symmetry site terms 5T. E. Sloan in Topics in Inorganic and Organometallic Stereochemistry, G. Geoffroy, ed., John Wiley & Sons, Inc., New York, 1981, 1-36. Configuration numbers depend first upon application of the Sequence Rule to determine order of seniority (priority) of atoms coordinated to the central atom. When constitutionally equivalent atoms are present, the same priority number is assigned to each; thus in Ma2b2c2, the order is 1,1,2,2,3,3. When a choice of configuration number is possible, preference is given to the atom of lower priority (higher numerical value). Tie-breaking is necessary with equivalent sets of polydentate ligand atoms. Chiral ligands, otherwise identical, are ranked with the R-form above the S-form. The chirality symbols C— for clockwise — and A— for anticlockwise (counterclockwise)—are used to denote absolute stereochemistry in coordination compounds, except that R and S are used for tetrahedral complexes, and ∆ (delta) and Λ (lambda) for octahedral complexes containing cis-bis(monodentate)bis(bidentate) ligands and tris(bidentate) ligands, respectively. Chirality symbols are placed after configuration numbers, which are determined and cited as follows: (a) Tetrahedral complexes (T-4) are assigned no configuration number. The chirality symbol R or S is assigned as for organic compounds with a single chiral center. (b) Square planar complexes (SP-4) have the ligating atoms at the corners of a square. The rank number of the atom diagonally opposite the senior atom (1) is cited as the configuration number. Three isomers are possible when all four ligands are different. Example: 1 3 Configuration number Stereochemical descriptor =4 = (SP- 4- 4)- 2 4 (No chirality symbol is required) (c) Trigonal bipyramidal complexes (TB-5). The configuration number comprises the rank numbers for the atoms at the ends of the major axis cited without punctuation in descending order of priority. If the complex has no reflection symmetry, the order of atoms in the plane perpendicular to the axis is expressed by C (clockwise ascending sequence of numerals, equivalent to descending priority) or A (anticlockwise) as viewed from the highest priority ligand on the major axis. Example: 1 2 4 Configuration number Chirality symbol = 13 =A = (TB-5-13-A)- M 5 3 Stereochemical descriptor (When all five coordinating atoms are different, 10 configurations are possible. Each is chiral, affording 20 possible stereoisomers.) (d) Square pyramidal complexes (SP-5) have a lone coordinating atom on the principal axis and four atoms in a square planar configuration at right angles to this axis. The first digit of the configuration number is the priority number of the lone atom; the second digit is the priority number of the atom situated diagonally opposite to the most senior coordinating atom in the plane. The chirality symbol is derived by viewing the plane from the position of the lone axial atom and tracing a path around the square plane from the most senior atom to the next most senior atom present. If this path is clockwise, C is the assigned chirality symbol; if anticlockwise, the symbol is A. Example: Configuration number Chirality symbol 3 1 2 = 25 =A = (SP-5-25-A)- Stereochemical descriptor M 5 4 (When all coordinating sites are unlike, 15 configurations are possible. Each is chiral, affording 30 possible stereoisomers.) ¶ 203 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 76 (e) Octahedral systems (OC-6) for which C and A can be used as chirality symbols (see above) have configuration numbers of which the first digit is derived from the priority number of the atom opposite to atom 1 and the second digit from the priority number opposite to the senior atom in the plane perpendicular to the axis containing atom 1. When no reflection symmetry is present, the chirality symbol is derived by viewing the plane from atom 1 and tracing a path clockwise (C) or anticlockwise (A) from the most senior atom to the next most senior atom. Examples: 1 6 3 The helicity symbol replaces the chirality symbol in octahedral complexes of this type. In the complex named in abbreviated fashion as [Co(1,2-pn)3]3+ the ligands themselves have chirality (denoted by R or S), and their geometry around the cobalt atom is described by use of “1” (for bonding to a secondary carbon) and “2” (for bonding to CH2). The helicity can be seen to correspond to the diagram above and the symbol ∆ is therefore appropriate. CH3 H2C CH 1 2 H N H2N 2 1 R R CH 3 1 R R 1 CH 1 Co3 + 2 NH2 CH2 2 Configuration number Chirality symbol = 24 =C = (OC-6-24- C)- H2N HC R ≡ 1 2 M 2 2 NH2 NH2 R M 4 2 5 Stereochemical descriptor CH 3 CH 2 Configuration number Chirality symbol Stereochemical descriptor = 21 =∆ = (OC-6-21-∆-(R),(R),(R)]- -H O ≡C PMe2 Ph + PMe2 Ph 2 Ru ClPMe2 Ph 2 ≡ 4 2 M 3 1 2 (The priorities of the ligand atoms are determined by arranging their atomic numbers (17,15,6 and 1) in descending order thus: Cl,P,C and H. There are three identical ligands of order 2; one is on the main axis (opposite ligand 1), the others are in the transverse plane opposite 3 and 4; the higher number is cited. The transverse pathway from the preferred 2 to the neighboring (less preferred) 2 is clockwise when viewed from atom 1.) Configuration number Stereochemical descriptor = 24 = (OC-6-24- C)- Octahedral complexes containing identical bis(tridentate) ligands are assigned geometric and chirality symbols in the same manner as normal octahedral complexes. However, in order to distinguish between enantiomers it is necessary to add primes to the donor atoms of one ligand. The primes are retained in the configuration number and this distinguishes between enantiomers. O H2C H N H2C -- O --- C O Co O O C 2+ -- CH2 N CH2 H ≡ 1 1´ 2 M 2´ 1´ 1 C O O C O For octahedral complexes with two or three bidentate ligands oriented in a skew configuration, the helicity symbols ∆ and Λ are employed instead of chirality symbols, they are related to right-handed and left-handed spirals, respectively, as follows: A A Configuration number Stereochemical descriptors = 1′ 1′ = (OC- 6- 1′ 1′ )- B N N B N N (f) Trigonal prismatic complexes (TP-6). The configuration number is obtained by citing the priority numbers of the three atoms opposite to (eclipsed by) the preferred triangular face, i.e., the face containing the maximum number of ligating atoms of highest priority (lowest numerals). These numbers are cited to correspond to the ascending numerical order of the respective eclipsing atoms. A chirality symbol, C or A, denotes the direction of numerical progression of the eclipsed atoms. Example: 3 1 2 5 6 4 Configuration number Chirality symbol Stereochemical descriptor = 526 =A = (TP- 6- 526- A) B A A B (a) ∆ (b) Λ In diagram (a) above, BB is a tangent to the right-handed helix that has axis AA and radius NN; (b) shows its mirror image, a left-handed helix. Turning each diagram through 90 degrees in either direction results in the simplified diagrams (c) and (d), respectively. B A B A B (g) Stereochemical descriptors were extended to 7-, 8-, and 9- coordinate complexes in CA indexes in 1977.6 In the following table, all 12 model polyhedra for 7-, 8-, and 9-coordinate complexes are shown, with examples of priority numbers for ligands from which configuration numbers are derived. 1. Pentagonal bipyramidal 3 2 1 2 3 4 4 4 2 1 4 3 3 2 A B A (c) (d) ≡ AA and BB have now lost their respective identities as axis and tangent and can be considered either as two tangents or as two segments of a double helix. BB is in front of AA in both diagrams; in (c), when AA is horizontal, BB descends to the right, in (d) to the left. In the octahedral complex, pictured as a regular octahedron in (e) below, the lines AA and BB represent two bidentate ligands oriented as in (c) above and represented by the helicity symbol ∆. (A third bidentate ligand, if it were present at CC, would not affect the helicity.) B A C C A B PB-7-34-12342 2. Octahedral faced monocapped 4 5 5 3 2 ≡ 2 4 3 1 1 2 2 1 1 (e) 6 OCF-7-4-213251 M. F. Brown, B. R. Cook, and T. E. Sloan, Inorg. Chem. 1978, 17, 1563 -1568. 77 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 9. Trigonal prismatic triangular faced bicapped 3 4 4 2 3 3 2 1 4 4 5 1 4 ¶ 203 3. Trigonal prismatic square faced monocapped 4 5 ≡ 2 ≡ 2 4 1 6 3 1 4 5 TPS-7-4-214345 5 4 4. Cubic 1 1 3 3 5 2 4 3 5 3 4 4 4 6 TPT- 8- 36- 142454 ≡ 2 1 3 1 3 10. Trigonal prismatic square faced bicapped 4 1 1 1 6 1 CU-8-13153234 2 6 2 3 ≡ 4 3 5. Square antiprismatic 1 1 5 2 2 3 1 2 3 4 2 5 5 2 TPS-8-13252416 ≡ 5 1 11. Trigonal prismatic square faced tricapped 2 5 2 4 2 2 4 SA-8-12522413 1 5 1 6. Dodecahedral 1 2 3 4 2 2 2 2 3 ≡ 4 2 1 1 2 4 4 3 4 1 1 1 5 ≡ 4 2 2 5 TPS-9-241251341 12. Heptagonal bipyramidal 2 2 3 2 DD-8-24122532 7. Hexagonal bipyramidal 5 6 1 3 2 3 5 1 3 1 4 3 1 5 1 1 3 5 6 2 3 4 ≡ ≡ 6 2 1 2 1 4 3 6 3 4 2 HB-9-22-1134165 HB-8-13-234653 8. Octahedral trans-bicapped 3 1 1 2 4 5 3 3 4 4 2 4 5 ≡ 4 4 3 OCT-8-33-124445 The configuration number is assigned by orienting the model structure with the highest-order axis in the vertical plane. The model structure is then viewed from the highest priority ligating atom on the highest-order axis or from a point on the highest-order axis above the most preferred end or terminal plane perpendicular to the axis. The most preferred end or terminal plane is that end plane which either contains the greatest number of atoms, contains the greatest number of highest priority ligating atoms, or is adjacent to a plane containing the greatest number of highest priority ligating atoms. (Note that the OCF-7 (octahedral faced monocapped), TPS-7 (trigonal prismatic square faced monocapped), and TPS-8 (trigonal prismatic square faced bicapped) model structures are of low symmetry and have only one correct orientation.) The configuration numbers for the model structures coded PB-7, OCF-7, TPS-7, HB-8, OCT-8, TPT-8, and HB-9 begin with the priority numbers of the ligating atom(s) on the highest-order axis and are given in lowest numerical order sequence. These priority numbers are separated from the remainder of the configuration number by a hyphen. The remaining portion of the configuration number is derived by viewing the structure from the highest-priority ligating atom on the highest-order axis, or from the axial ligating atom located ¶ 203 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Trigonal prismatic square faced monocapped (TPS-7) 2 78 above the preferred plane, and by citing the priority number of the ligating atom with the highest priority in the plane adjacent to that atom. The configuration number is then completed by continuing to cite the priority numbers of the ligating atoms in sequence as they are encountered, either clockwise or anticlockwise around the projection of the model structure, alternating between planes where necessary, when viewing from the highest priority atom. For those model structures with eclipsed pairs of ligating atoms, the priority numbers are given in pairs with the priority number for the preferred atom in the first plane followed by that for the eclipsed atom. The remaining priority numbers are given as they are encountered, either clockwise or anticlockwise around the projection of the model structure as viewed from the preferred end of the highest-order axis. For compounds in which clockwise and anticlockwise citations of the configuration number give two different configuration numbers (generally chiral compounds), the correct one is the lower numerical sequence as determined at the first point of difference. The remaining five model structures, CU-8, SA-8, DD-8, TPS-8, and TPS-9, do not have a ligating atom on the highest-order axis and thus do not have a distinct portion of the configuration number set off by a hyphen. These model structures are viewed from a point on the highest-order symmetry axis above the preferred terminal plane as defined previously. The configuration number is derived by first citing the priority number of the preferred ligating atom in the preferred end plane and then citing the priority number of the ligating atom it eclipses, if one exists. In the next step, one proceeds clockwise or anticlock-wise around the projection of the model structure, giving the priority numbers of the ligating atoms as they are encountered, alternating between planes when necessary. Again, the clockwise or anticlockwise direction is chosen to give the lowest-order numerical sequence for the configuration number as determined at the first point of difference. When there are two or more equivalent bidentate or tridentate ligands and the same priority numbers thus occur in equivalent ligands, the ties are broken by identically priming all the CIP priority numbers of the ligating atoms within a ligand to determine both the configuration number and the chirality symbol. In those complexes with symmetrical polydentate ligands, tetradentate, hexadentate (including symmetrical macrocyclic) ligands, etc., ties between equivalent ligating atoms are broken by priming the ligating atom priority numbers in chelating groups or pairs, thereby reducing the polydentate ligand to groupings of equivalent bidentate or tridentate ligands. When two or more nonequivalent tie-breaking choices exist for the coordination polyhedra of coordination numbers 7, 8, and 9, the tie is resolved by (a) assigning the lowest priming to the preferred symmetry axis or plane, and (b) assigning the lowest priming to give the lowest numerical value to the configuration number at the point of difference. Primes are restricted to the configuration number for octahedral complexes containing two identical tridentate ligands and trigonalprismatic complexes containing two or more identical polydentate ligands and for all 7, 8 and 9 coordinate complexes. The use of primes is exemplified by the first example below, which is explained in some detail. Examples: Pentagonal bipyramidal (PB-7) F1 1 2 2 - Cl 2 5+ F2 Ta -F F2 FCl1 ≡ 2 2 1 2 2 (TPS-7-2-122212-A)(The direction must be selected so as to cite the priority number of the atom in the next lower plane.) Cubic (CU-8) Cl - Br 2 1 3 5+ 2 4 OH2 F5 5 4 2 2 - Cl P a Cl 2 NH3 ≡ 2 4 1 3 H2O 4 (CU-8-13242542-A)(Each face must be tested to determine the preferred terminal plane. As drawn in this example, the preferred face (terminal plane) is on the left side of the cube. Consequently the cube must be re-oriented before assigning the descriptor.) Square antiprismatic (SA-8) Br 2 1 F1 4 3 - Cl OH2 5+ Ta 5 4 ≡ 4 2 3 CH3 H2C H2C H C N 4´ 2´ 3 N 1Cl- C 2 CH3 2´ 3 1 2 5 1 4 2 N 4 Fe 3+ Cl C 1 CH2 CH2 H ≡ H3N OH2 1 4´ N- N CH 2 4 - Br 1 Cl 2 H2 (SA-8-14324125-C)(PB-7-11-232´4´4)(The preferred orientation must be determined before the descriptor assigned.) The ligands of highest atomic number (chlorine) are numbered 1. An exploration table (not shown) may be needed to establish the order of priorities (2,3, and 4) of the nitrogen ligands.7 No chirality symbol (C or A) is needed. Octahedral faced monocapped (OCF-7) BrF3 5 6 3 1 Dodecahedral (DD-8) H 3C 1´ 1 1´´ CH3 1´´ 1´´ C 1 1 O H2O 2 O NH3 4 HCC O 1´ 3+ Nb 4 ≡ Br1 OC O C CH3 - CH - CH CH3 Ho+ C 3 OC O 1´´ 1 ≡ 1´ 1´ 1 1 5 2 6 H3C CH3 H2O 2 2 2 H2O Cl2 (DD-8-111´´1´´1´1´22)(OCF-7-1-316254-C)(The preferred orientation must be determined before the descriptor is assigned; also, the pathway is selected to pass through the atom of highest priority (lowest numerical value) in the next lower plane.) S. Cahn, C. K. Ingold, and V. Prelog, Angew. Chem. Int. Ed. Engl. 1966, 5, 391-395. 7R. 79 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Heptagonal bipyramidal (HB-9) ¶ 204 Hexagonal bipyramidal (HB-8) 3 S 2 Me Me Br 5+ 1 2 1 1 2 3 3 5 Cl - 2 Cl Ta S F4 2 Cl - S 3 Me Me ≡ Br U -F 4 Br 5 6+ 1 1 1 5 4 OH2 Me S H2O 4 ≡ 5 2 4 3 Me Me 3 F4 Cl 2 3 Me 4 2 (HB-8-34-122343-A)- F4 Octahedral trans-bicapped (OCT-8) 5 (HB-9-24-1153245-C)- Br-Cl U 16 2 4 1 1 O 1 6 5 5 4 Trigonal prismatic square faced tricapped (TPS-9) 4+ OH2 ≡ 2 Br F3 NH3 3 2 2 F1 2 3 5 ^^^ ^^^ 2 ^^^ ^^^ 2 1 ^^^ 4 (OCT-8-55-112346-A)- assigned.) - Cl 2 5 NH3 OH2 4 Trigonal prismatic triangular faced bicapped (TPT-8) 5 H3N O 4 6 (TPS-9-143352226-A)- ClRe 3 + 4 OH2 2 Br - 1 6 ≡ 2 5 5 1 3 H3N 6 F3 6 O 5 (TPT-8-55-132664-C)- (The preferred orientation must be determined before the descriptor is assigned.) Trigonal prismatic square faced bicapped (TPS-8) OH N O N H O 2 O N 5 4 4 OH2 O 1 O H N N H O 5 4 OH2 4 2+ N O 3 Sr 4 ≡ 2 3 Mononuclear coordination complexes containing ligands which require the use of η do not follow the stereochemical rules for other mononuclear coordination complexes. When the author indicates stereochemistry for the total complex, the term “stereoisomer” is used. Ligand stereochemistry in πcomplexes is described using the rules for systematic organic stereochemistry (see ¶ 203 I). No ligand stereochemical descriptor is cited unless all ligand stereochemistry can be described. However, ligand stereochemical descriptors are cited even if the geometry about the metal is unknown. When more than one ligand is stereogenic, the stereochemistry for the complex is cited as if all ligand stereochemistry is in one organic ligand. An exception is made for metallocenes. Metallocenes, when asymmetrically disubstituted, are not superimposable on their mirror images; they can therefore exist as enantiomers. The absolute configuration of the chiral center of highest priority is determined by the Sequence Rule and cited as R or S when specific information is stated in the original document. (The configuration of the other four centers is then fixed.) Metallocenes which have stereochemistry only in the substituents have that indicated as described by the rules in I above. Partial stereochemistry is not cited for coordination compounds. 204. Alkaloids are divided into classes largely in accordance with their stereochemical complexity. Class A alkaloids include substances containing only one chiral center, or none at all, or whose stereochemistry, typically restricted to a single ring system, is easily defined. Alkaloids of this class are indexed systematically; cross-references are found at the alkaloid names. Example: Tropine See 8-Azabicyclo[3.2.1]octan-3-ol, 8-methyl-, (3-endo)Class B alkaloids possess more complex stereochemistry. They have been organized as derivatives of a single stereoparent of known absolute configuration common to several alkaloids. (Class C alkaloids are those which have not yet been organized in this way, but whose absolute configuration is known.) Class B stereoparents are illustrated in the Chemical Substance Index when justified by current entries. The following is a partial list of those currently employed for alkaloids: OH2 4 4 1 OH2 4 (TPS-8-13445244-A)- (The pathway is selected to pass through the atom of highest priority (lowest numerical value) in the next lower plane.) ^^^ (The preferred orientation must be determined before the descriptor is 6 6 ^^^ - Cl ^^^^^^^^^^^^^^^^^^^^^^ F 5+ Re ^^^^^ ^^^^^ ^^^ H ^^^ ^ ^^^ ^^^ ^^^ ^^^ ^^ 3 ^^^ 5 3 ^^ O - Cl Br - ≡ ^^^^^^^^^^^^^^^^^^^^^^^^ ^^^ ^^^ 3 ^^^ ^^ ^^ ^^^ ^^ ^^ ¶ 204 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Hasubanan Hetisan Ibogamine Morphinan Oxayohimban Sarpagan Solanidane Strychnidine Veatchane Yohimban stereoparents: 80 Aconitane Ajmalan Aspidospermidine Cevane Cinchonan Curan Eburnamenine Ergoline Ergotaman Erythrinan 6,14-Ethenomorphinan Deviations in stereochemistry for specific derivatives of Class B alkaloids are indicated in the modification (¶ 203 II). The prefixes, suffixes, conjunctive names, etc., of regular substitutive nomenclature are employed in naming derivatives. Radicals, e.g., aconitanyl, are formed from the stereoparent names in the usual way. Ring modifications as expressed by prefixes such as cyclo, homo, nor, and seco, on the heading parent, are not permitted and systematic nomenclature is used. Carboxylic acids are formed from Class B stereoparents by oxidation of an existing carbon to form an “-oic acid” or by addition of a carboxyl group to form a “-carboxylic acid”; the latter type of name is preferred if a choice is presented. Removal of hydrogen is indicated by “dehydro” terms in the inverted part of the heading. Class C alkaloids are indexed at stereoparent names supplied in the literature, the numbering system is that most commonly adopted in original documents, and the numbering is extended, if necessary, to include all positions except acyclic hetero atoms. The latter are denoted by italic element symbols, with superscripts, if necessary, derived from the lowest numbered atom to which the hetero atom is attached, e.g., N 6, O2. Illustrative diagrams in the Chemical Substance Index at Class C alkaloid names, currently Cephalotaxine and Vincaleukoblastine, indicate the stereochemistry and numbering systems. Derivatives of Class C alkaloids are named, when sufficient information is presented, by modifying the stereoparent name. Suffixes are not used except for “-oic acid,” to denote oxidation of a methyl group or removal of an ester group. “Hydro” terms are employed to indicate saturation of positions; “de” terms, e.g., “dehydro,” “deoxy,” “deepoxy,” “deoxo,” “demethyl,” “de(methoxycarbonyl),” denote removal of atoms or groups, which may be replaced by other groups; e.g., Vincaleukoblastine, 3-de(methoxycarbonyl)-3-(hydroxymethyl)-. Higher functions attached to Class C stereoparents are indexed as substituents. When an alkaloid derivative can be named at two or more Class C stereoparents, the decision depends in descending order of preference on (a) removal of the fewest different substituents; (b) removal of substituents of lowest molecular weight; (c) retention of the stereoparent of highest molecular weight; (d) addition of prefixes related to the lowest number of smallest substituents; (e) the least stereochemical change; (f) the lowest locants for substituents; (g) the earliest index positions of the index name. Derivatives of Class C alkaloids that meet the criteria for Class A alkaloids are named systematically by substitutive nomenclature. When a Class C stereoparent structure contains an oxo group, derivatives of the group, e.g., oximes or hydrazones, are expressed in the modification; otherwise they are expressed as substituents, e.g., as (hydroxyimino) or hydrazinyldene radicals. Esters are named analogously in the modification or by (acyloxy) or [(alkyloxy)carbonyl] substituents. Stereochemical deviations of Class C alkaloid derivatives are expressed as the final term in the modification in the usual way. Quaternary alkaloids are either (a) alkaloids that contain a cationic nitrogen atom, or (b) alkaloids that have been quaternized, e.g., by methylation of a tertiary nitrogen group. Names of (a) are completed by citing the anion (if known) in the modification, e.g., “chloride”; (b) are usually named by adding “ium” to the neutral alkaloid name, and indicating the quaternizing substituents as in regular substitutive nomenclature; e.g., Morphinanium, 17,17-dimethyl-, iodide (1:1) by quaternization of Morphinan). When the location of the quaternary center is unknown, the “ium” ending is omitted and the quaternary compound is named as alkaloid compd. with iodomethane (1:1). Nonquaternary derivatives of the alkaloids described in (a), above, are named by subtractive prefixes, e.g., demethyl, or by “dihydro” terms. Removal of a methyl group from the carbon skeleton of an alkaloid is indicated by “nor” with the locant of the carbon atom lost, but removal of a methyl group from a hetero atom is expressed by “demethyl.” Ring contraction and enlargement in alkaloids is not permitted, and revert to systematic nomenclature. Ring closure may be effected by insertion of heteroatoms (other than nitrogen) as bridges while maintaining stereoparent nomenclature, e.g., Aspidospermidine, 19,21-epoxy-. Such a bridge may also include one carbon atom, e.g., 6,14-Ethenomorphinan, 7,5-(methyleneoxy)-. Replacement of one carbon atom by a heteroatom or insertion of additional nitrogen or replacement of existing nitrogen is not permitted. Seco alkaloids are formed by ring cleavage and addition of hydrogen at the resulting terminal groups. Such compounds are given systematic names. Ring-fused derivatives of alkaloid stereoparents are named systematically. Degradation products of alkaloids in which ring cleavage and removal of large portions of the molecule still leave intact some rings and the original stereochemical relationships are named, when possible, as derivatives of a smaller alkaloid stereoparent. When this is impossible and the structure is known, degradation products of Class C alkaloids are named systematically, but, for those of unknown structure, only the author’s names are employed. For steroidal alkaloids, see ¶ 211. 205. Amino acids. The following biologically significant amino acids are Alanine β-Alanine Alloisoleucine Allothreonine Arginine Asparagine Aspartic acid Cysteine Cystine Glutamic acid Glutamine Glycine Histidine Homocysteine Homoserine Isoleucine Isovaline Leucine Lysine Methionine Norleucine Norvaline Ornithine Phenylalanine Proline Serine Threonine Tyrosine Tryptophan Valine The following amino carboxylic, amino sulfonic, and amino arsonic acids, indexed prior to 1972 at their trivial names, are now named either systematically or as derivatives of an amino acid listed above: Trivial name Allocystathionine Anthranilic acid Arsanilic acid (3 isomers) Carnosine Creatine Cystathionine Ethionine Hippuric acid Lanthionine Metanilic acid Panthothenic acid Sarcosine Sulfanilic acid Taurine Thyronine Thyroxine CA Index Name Homocysteine, S-(2-amino-2-carboxyethyl) Benzoic acid, 2-aminoArsonic acid, As-(aminophenyl)Histidine, β-alanylGlycine, N-(aminoiminomethyl)-N-methylHomocysteine, S-(2-amino-2-carboxyethyl)Homocysteine, S-ethylGlycine, N-benzoylCysteine, S-(2-amino-2-carboxyethyl)Benzenesulfonic acid, 3-aminoβ-Alanine, N-(2,4-dihydroxy-3,3-dimethyl1-oxobutyl)- (see ¶ 224) Glycine, N-methylBenzenesulfonic acid, 4-aminoEthanesulfonic acid, 2-aminoTyrosine, O-(4-hydroxyphenyl)Tyrosine, O-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo- The configurational descriptors D- and L- are placed before the stereoparent names; no descriptor is cited for the optically inactive mixture or racemic form; thus, L-Leucine; D-Valine; Phenylalanine. In the absence of contrary evidence, the L-isomer is assumed for amino acid stereoparents, except Glycine and βAlanine, which possess no asymmetric center, and Alloisoleucine and Allothreonine (see below). When the original document clearly indicates that an amino acid is synthetic, it is indexed as the racemic form. The same assumptions are made for their radicals, which are employed in peptide nomenclature, and for derivatives such as esters, salts, and N-, O-, and S-derivatives indexed at the stereoparent. No assumptions are made for carbon-substituted derivatives or for derivatives named systematically. Systematically named amino acids of known stereochemistry are assigned the absolute descriptors R and S in the modification. Of the diastereoisomeric pairs, assumptions in favor of Isoleucine over Alloisoleucine and of Threonine over Allothreonine are made. The absolute descriptors R and S (with locants) are cited in the modifications of diastereoisomeric derivatives of amino acid stereoparents to define the second asymmetric center, e.g., L-Aspartic acid, 3-hydroxy-, (3R)- and L-Proline, 4-methyl-,(4S)-. Phenylalanine is a stereoparent employed for Alanine, 3-phenyl-. It is treated in substitutive nomenclature as though it were the conjunctive name Benzenealanine. The naturally occurring isomer is L-Phenylalanine, which affords the radical L-phenylalanyl. Derivatives containing higher functions or more preferred ring systems are named systematically according to the regular rules. Example: PhCH 2 C(NH2) CO 2H 1-Naphthaleneacetic acid, α-amino -α-(phenylmethyl)- L-alanyl, L-phenylalanyl, Radicals derived from the names of amino acid stereoparents, e.g., glycyl, are employed only in naming peptides (¶ 206). In other situations, systematically named radicals are used; e.g., (2-aminoacetyl) instead of glycyl. The phenylalanyl radical is considered to be a specially named one -part radical; no parentheses are placed around it when it is unsubstituted. Stereoparent radical names are derived by replacing the final “-ine” by “-yl” (an exception is Cysteine, which affords cysteinyl); Tryptophan gives tryptophyl; Aspartic acid and Glutamic acid radicals are as follows: 81 -COCH2CH(NH2)COHO2CCH2CH(NH2)CO-COCH2CH(NH2)CO2H -CO(CH2)2CH(NH2)COHO2C(CH2)2CH(NH2)CO-CO(CH2)2CH(NH2)CO2H Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 aspartoyl α-aspartyl β-aspartyl glutamoyl α-glutamyl γ-glutamyl HO2CNHCHMeCO2Et Examples: EtO2C(CH2)2CH(NH2)CO2Me L-Glutamic ¶ 206 acid, 5-ethyl 1-methyl ester L-Alanine, N-carboxy-, 1-ethyl ester (the locant “l” is cited for clarity, even though the N-ethyl ester is indexed as L-Alanine, N-(ethoxycarbonyl)- (¶ 185)) Amino acids are given less preference for special treatment than other stereoparents. They are ranked just above the unsubstituted parent acids; thus, Alanine (2-aminopropanoic acid) is ranked above Propanoic acid but below Butanoic acid. All carbon-substituted derivatives of Glycine and β-Alanine are indexed at systematic names, but the carbon-substituted radicals are permitted in peptide nomenclature. Examples: BzNHCH2CO2H N 2 1 Glycine, N-benzoyl- L-Phenylalanine, Cl CHEt CH(NH 2) CO 2 H β α 4-chloro-βethyl(βR)- (not L-Norvaline, 3(4-chlorophenyl)-,(3R)-) Amides of amino acids are indexed at systematic names, e.g., Acetamide, 2-amino- (not Glycinamide), but peptide amides (¶ 206) are indexed at C-terminal amino acid names, e.g., Glycinamide, L-alanyl-. Anhydrides of amino acids are indexed at the amino acid name with “anhydride” or “anhydride with” terms in the modification. Cyclic anhydrides and lactones are indexed as heterocycles. Hydrazides are indexed at acid headings with “hydrazide” terms in the modifications. Molecular addition compounds of nonstereoparents with amino acids named as stereoparents receive preferred index names at the latter, but Formula Index entries will be found also at the other component(s). The preferred name of an addition compound of two or more stereoparents is chosen on the basis of the maximum number of highest functions in the stereoparent. Beryllium, magnesium, aluminum, gallium, indium, thallium, and transition-metal salts of amino acids are indexed as coordination compounds (¶ 215) if sufficient information is presented, and the special stereochemical descriptors (¶ 203 III) for such compounds are then adopted. Other salts are indexed at such names as Glycine, sodium salt (1:1); L-Phenylalanine, methyl ester, hydrochloride (1:1). Example: Me(CH2)5CMe(NH2)CO2H Octanoic acid, 2 -amino -2 -methyl(not Alanine, α-hexyl-) HS ( CH2 ) 2 H2 N 2 + H2 N ( CH2 )2 SH Cu O O O O PhCH(NH2)CH2CO2H Benzenepropanoic acid, β-amino(βR)- (not β-Alanine, 3-phenyl-, (3R)-) Copper, bis (L- homocysteinato κN, κO)-, (T-4)- O-Substituted derivatives of the hydroxy amino acids (Allothreonine, Homoserine, Serine, Threonine, and Tyrosine) and S-derivatives of the mercapto amino acids (Cysteine and Homocysteine) are named at those stereoparents, e.g., Serine, O-methyl- and L-Cysteine, S-acetyl-. The stereoparent Methionine, CH3SCH2CH2CH(NH2)COOH, is the S-methyl derivative of Homocysteine. Derivatives in which this methyl group is substituted are indexed as Homocysteine derivatives. S-Oxide derivatives of Cysteine and Homocysteine are indexed as sulfinyl and sulfonyl derivatives of simpler parents; however, S-oxides of S-substituted derivatives (including Methionine) are named as such. Conjunctive names are not formed from amino acid stereoparents attached to ring systems; instead, such a combination is usually indexed at a systematic conjunctive name with an “α-amino” substituent. Derivatives of Arginine, H2NC(:NH)NH(CH2)3CH(NH2)COOH, substituted in the guanidino group are indexed as derivatives of Ornithine, H2N(CH2)3CH(NH2)COOH. Histidine (R = H) is capable of existing in the following tautomeric forms: R N CH2 CH (NH2) CO2 H N (a) RN (b) N CH2 CH (NH2) CO2 H 206. Peptides are generally named by use of amino acid stereoparents (¶ 205) and stereoparent radicals; the L-isomers are assumed for indexing purposes in the absence of contrary information. Trivial names of some peptides and all proteins are employed, and special “Cyclo” names are used for tri- and higher cyclic peptides. Linear peptides without trivial names are indexed at “amino acid sequence names.” The heading parent is the C-terminal amino acid. Enclosing marks and locants for points of attachment of the amino acid radicals are omitted; however, Greek-letter locants are cited for aspartyl and glutamyl radicals, and “N 6- ” and “N 5- ” are used with Lysine and Ornithine, respectively, and their radicals, when the attachment is not on the α-amino group (N 2-position). NDerivatives of the radicals are expressed as substituents. Esters of carboxy groups of aspartic and glutamic acid residues are cited in the modification; Oand S-acyl derivatives of seryl, cysteinyl, etc., radicals are named as, e.g., Oacetyl-L-seryl, etc., radicals and even when a hydroxyl- or mercapto-groupcontaining amino acid is the heading parent, the O- or S-acyl group is treated as a substituent. Examples: H-L-Met-L-Asp(NH2)-L-Pro-D-Phe-L-Phe-OH L-Phenylalanine, Lmethionyl-L-asparaginyl-Lprolyl-D-phenylalanyl- When the tautomers are stabilized by substitution on a nitrogen atom of the ring, two isomers result. The side chain has been arbitrarily assigned to the 4position of the ring and, if R = ethyl, the structures shown above are indexed: (a) L-Histidine, 3-ethyl(b) L-Histidine, 1-ethylIt should be noted that while (b) conforms to the correct treatment for 1H-Imidazole, the numbering of (a) violates the rules (3H-Imidazole is not used as a heading parent) and is adopted only for these special cases. A 1substituent is assumed in indexing indefinite 1- or 3-derivatives of Histidine. Esters of amino acid stereoparents with nonstereoparents are indexed at the amino acid names; e.g., L-Alanine, 4-carboxyphenyl ester. Esters with other stereoparents are indexed at the parent which represents the greatest number of highest functions. Usually only one index entry is made for an ester. Locants are used with ester terms when necessary. HO2CCH2 CO 2H | | H2NCHCONHCHCONHCHCH2 OAc | MeSCH2 L-Tyrosine, L- α- aspartyl S -methyl -L -cysteinyl -O - acetyl- ¶ 206 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 82 MeO2 C(CH2 )2 (CH2 )2 CO2 Me | | PhCH2O2CNHCHCONHCHCONHCHCONHCHCO2Me | | (CH2)2CO2Me MeO2 C(CH2 )2 L -Glutamic acids are assigned “Cyclo” names formed by citing the amino acid radicals (with substituents) as for an amino acid sequence name, placing them in enclosing marks, and prefixing the term “Cyclo”. The order of citation is by lowest alphabetical order of parent amino acid residues (substituents are disregarded) when the residue is standard, but when it is nonstandard (e.g., 2aminobutanoyl), substituents are included in determining the order of citation. Cyclo[L-alanyl-N 5-acetyl-D-ornithylglycyl -L-alanyl -D-prolyl -O(1,1-dimethylethyl)-L-seryl] (note NH - CH - CO - NH - CH2 - CO - NH - CH - CO that the substituent “acetyl” is disregarded in determining preferred ciN CO - CH - NH - COCH - NH - CO tation of the peptide sequence; the lowest alphabetical sequence of parCH2 OCMe3 Me ent-radical initial letters is “a, o, g, a, p, s”) ( CH2 ) 3 NH Ac Me acid , N [(phenylmethoxy)carbonyl]-Lα-glutamyl-L-α-glutamyl-Lα-glutamyl- , 1,2,3,41,45-pentamethyl ester H N (CH2)2SMe CH 2Ph | | CH2CHCONHCHCONHCHCONHCHCONHMe | | CH2CO2H NH2 L-Phenylalaninamide , L-tryptophyl-Lmethionyl-L-α-aspartyl-N-methyl- To be named as such, a linear peptide must have at least two standard amino acids. In peptide nomenclature, standard amino acids are defined as amino acid stereoparents (¶ 205), plus α-Asparagine, H2NCOCH(NH2)CH2COOH, and α-Glutamine, H2NCOCH(NH2) (CH2)2COOH. Peptides that do not meet this requirement are named systematically; e.g., Butanoic acid, 4-amino-2-[(2aminoacetyl)amino]-, (2S)-. When the above requirement is met, nonstandard α-amino acids are allowed as residues in terminal or nonterminal positions. Nonstandard amino acids in which the amino group is not α to the carbonyl are allowed provided they are nonterminal. All nonstandard amino acids are assigned systematic acid or acyl names. Absolute stereochemistry is described by the use of R/S terms preceded by locants; e.g., L-Alanine, 5-oxo-L-prolyl-(αS)-αamino-4-chlorobenzenebutanoyl-; 1H-Indole-2-carboxylic acid, Lseryl-L-methionyloctahydro-, (2S,3aR,7aR)-; L-Proline, L-histidyl(3R)-3-(methylamino)hexanoylglycyl-L-α-aspartyl-. Branched-chain peptides may comprise N 5- or N 6- isopeptide derivatives of Ornithine or Lysine, respectively, or O- or S-derivatives of hydroxy or mercapto amino acids (heterodetic homomeric peptides). Both types are named as substituted derivatives of the parent linear peptides. Examples: H-L-Ala-D-Gln-L-Lys-D-Ala-OH H-L-Ala-D-Gln-L-Lys-D-Ala-L-Ala-L-Ala H-L-Ala-L-Ala D -Alanine, L -alanyl -D -glutami nyl - N 6 -[ L - alanyl - D - glutami nyl - N 6- ( L- alanyl- L- alanyl )-L- When ring formation has taken place by way of a side-chain peptide linkage, the acyclic peptide is named and the linkage expressed in the modification by a phrase of the type “(10→4)-lactam” in which the lactam linkage is denoted by amino acid residue locants (numbered from the N-terminus) with the acid end of the linkage cited first. Peptide lactones not assigned depsipeptide names (see below) are expressed by modification terms such as “ (3→1)-lactone.” Peptides containing disulfide linkages are indexed at the reduced (cysteinyl-group-containing) form with terms such as “(2→2´)-disulfide,” “cyclic (1→6)-disulfide” and “(5→3´)-disulfide with ...” in the modification. N-(Peptidyloxy) derivatives of nitrogenous heterocycles are indexed at the peptide names, with the rings cited as ester terms. Depsipeptides contain ester linkages with hydroxy acids as well as amide (peptide) linkages with amino acids. Those with three or more acid residues, of which at least two are standard amino acid residues, are indexed by “depsipeptide nomenclature”; otherwise a systematic name is employed. A depsipeptide name is based on the C-terminal amino acid and indexed by methods analogous to those for amino acid sequence names. Trivially named hydroxyacyl radicals (lactoyl, glycoloyl, etc.) are given systematic acyl radical names when nonterminal, but treated as substituents or ester terms when terminal. Example: HOCHMeCONHCHMeCO2CHMeCONHCHMeCO2H L-Alanine, N-[(2R)-2-hydroxy-1-oxopropyl]L-alanyl-(2R)-2-hydroxypropanoyl- Cyclic didepsipeptides are indexed as heterocycles. Cyclic tri- and higher depsipeptides are indexed at “Cyclo...” names analogous to those for cyclic peptides. Cyclic depsipeptides with one hydroxy acid are named as such, not as lactones. Example: lysyl -D -alanyl -L -alanyl -L -ala nyl ]-L -lysyl H-L-Leu-L-Ala-L-Phe H-L-Pro-L-Met-L-Ser-L-Asp-OH L-Aspartic acid, L-prolyl-L-methionyl-O-(L-leucyl-L-alanyl-L-phenylalanyl)-L-seryl- Me CH2OH O - CH - CO - NH - CH - CO CO - CH - NH - CO - CH -NH CH2CHMe2 CH2 Ph Cyclo[(2S)-2-hydroxypropanoyl-L-seryl-L-phenylalanyl-L-leucyl] (the hydroxy acyl radical is alphabetized at “h,” not “p”) Higher functions in peptides are expressed as substituents. When the C- terminal residue is not an amino acid or amino acid amide, but an acid-related compound such as an alcohol, aldehyde, or nitrile, the adjacent amino acid amide residue is adopted as the heading parent, and the terminal group is expressed as an N-(cyanomethyl), N-(2-oxoethyl), etc., substituent. Cyclic dipeptides are indexed at systematic heterocycle names, with crossreferences at “Cyclo” names (see below). Example: O 8a 1 The Greek letter ψ, shorthand for “pseudo,” is used to convey the fact that a peptide bond has been replaced by a pseudopeptide bond. If the structure contains the moiety ...-NH-CHR-X-X´-CHR´-CO-..., where R and R´ are amino acid side-chain groups and X and X´ are the groups that replace the peptide bond, then the format of the ψ term is ...-A-ψ(X-X´)-B-..., where A is the amino acid whose carbonyl group has been modified to X (or remains unmodified) and B the amino acid whose α-amino group has been modified to X´ (or remains unmodified). X and X´ are shown as strings of element symbols, separated by a bond; e.g., L-Leucine, L-alanyl-L-valyl-ψ (CH2-CH2) -Lisoleucyl -L-alanyl-. Naturally occurring biologically active peptides with five or fewer amino acid residues are indexed as described above. The more common natural peptides with six to fifty residues are assigned the trivial names commonly used in the literature. For cysteine-containing natural peptides, only the reduced form is illustrated (Oxytocin and Vasopressin, below, are exceptions). Examples: H-L-Arg-L-Pro-L-Pro-Gly-L-Phe-L-Ser-L-Pro-L-Phe-L-Arg-OH 1 2 3 4 5 6 7 8 9 H2 N N 5 Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro- O Bradykinin Tripeptides and longer peptides containing two or more standard amino 83 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 208 → L-Leu-D-Phe-L-Pro-L-Val-L-Orn L-Orn←L-Val←L-Pro←D-Phe←L-Leu ← 10 9 8 7 6 1 2 3 4 5 Gramicidin S sulin (cattle), 30B-L-methionine-. The reduced forms of the individual insulin chains are also stereoparents; internal disulfide bonds are expressed in the modification. Actinomycins are a class of natural products that contain peptide chains attached to non-peptide moieties. Actinomycin D (sometimes called C1) is one member of the actinomycin family. Example: 5 B 5 A Me - L - Val - O MeGly H-L-Cys-L-Asn-L-Cys-L-Lys-L-Ala-L-Pro1 2 3 4 5 6 L-Pro 3 4 B B Me - L - Val - O MeGly 4 A Actinomycin D L-Pro 3 A D-Val 2 A L-Glu-L-Thr-L-Ala-L-Leu-L-Cys-L-Ala-L-Arg7 8 9 10 11 12 13 L-Arg-L-Cys-L-Gln-L-Gln-L-His-NH2 14 15 16 17 18 D-Val 2B CO-L-Thr 1B 9 10 CO-L-Thr 10a 1 1 A N NH2 N Apamin (reduced) 6 12 Me O 5 4 O Me 11 Species variations are dealt with by citing the name of the species as a homograph definition after the heading. Each species variant is an independent stereoparent; e.g., Calcitonin (salmon reduced); Calcitonin (human reduced). Replacement of one amino acid residue by another is indicated at a trivially named peptide heading by citing the names of the new amino acids in numerical (not alphabetical) order as substituents; e.g., Glucagon (swine), 4 -L serine-10-L-alanine-. In addition, the chain of the reference compound can be extended at either end, either by substitution of the N-terminal α-amino group or by citing additional terms with locants derived from the highest present by addition of “a,” “b,” etc. In a similar manner, insertion of amino acid units between existing ones is indicated by “endo” terms with “a” locants derived from the lower of the two neighboring units (e.g., “3a” indicates insertion between “3” and “4”). Removal of a unit is indicated by a “de” term such as “4-desulfo” to indicate removal of only a modifying group in a unit, or “6-de-L-glutamic acid” to express removal of an entire unit. Examples: Kallidin, N2-L-alanyl- (N-terminal extension) Glucagon (swine), N-acetyl- (N-terminal extension) Bradykinin, 9a-L-valine-9b-L-lysine- (C-terminal extension) Fibrinopeptide A (human), 16a-D-serinamide- (C-terminal extension) Bradykinin, 6a-endo-L-alanine- (insertion) Caerulein, 4-desulfo- (removal of modifying group) Caerulein, 4-de(O-sulfo-L-tyrosine)- (removal of unit) Combinations of various types of structural modifiers are indicated by citing them in numerical order. When the modifying operations total at least one-half the number of units in the original parent, a regular peptide name is employed. The Greek letter ψ (see above) is used in derivative names to indicate a modified peptide bond. The format of the ψ term is ...-A-nψn+1(X-X′)-B-..., where n is the residue number of the amino acid A whose carbonyl group has been modified to X (or remains unmodified) and n+1 the residue number of the amino acid B whose α-amino group has been modified to X′ (or remains unmodified). A and B are cited in the name only if they are otherwise modified; e.g., Bradykinin, 7ψ8(CH=CH,E)-8-L-tyrosine-. The formatting of the stereochemical data for X-X′ follows standard literature practice. In Angiotensin I and Angiotensin II, the amino acid in the 5-position, if known, is cited in the inverted part of the heading, e.g., Angiotensin I, 5- Lisoleucine-. Oxytocin and Vasopressin derivatives in the disulfide form are named at these headings with replacement, etc., terms as usual, but reduced analogs are indexed at amino acid sequence names, not at Oxytocin (reduced) and Vasopressin (reduced). The amino acid at position 8 of Vasopressin is always specified if known. In α1-39-Corticotropin (swine) “α” indicates that this was the first principle isolated; the superscripts give the range of amino acid units. Fragments containing more than twelve sequential units receive names such as α1-24-Corticotropin and α11-39-Corticotropin. An amino acid sequence name is employed for fragments of fewer than twelve units. Insulin contains two peptide chains, an A-chain of 21 amino acid units and a B-chain of 30 units, connected at two points by disulfide bridges. Replacement names that retain the disulfide bridges and have fewer than 11 and 15 residue changes in the A- and B-chains, respectively, are formed in the usual way. Locants have superscript letters to indicate to which chain they belong; e.g., In- The “Me-L-Val” symbol denotes N-methyl-L-valine and “Me-Gly” denotes N-methylglycine (sarcosine). Substitution in the phenoxazine ring is expressed before amino-acid replacement, etc., in the peptide moiety. Examples: Actinomycin D, 8-bromo-7-chloroActinomycin D, 2-deamino-2-hydroxy-3Α-D-proline-4Α-DnorleucineHomopolymers of amino acids are indexed by polymer procedures (¶ 122); e.g., L-Alanine, homopolymer. The structural repeating unit is indexed at Poly[imino[(1S)-1-methyl-2 -oxo-1,2 -ethanediyl]]. The stereochemical assumptions are the same as for the monomeric amino acids. Peptides of indefinite molecular weight with repeating peptide sequences are named as homopolymers at the peptide monomer names and at structural repeating unit names. 207. Proteins. Proteins are arbitrarily defined for indexing purposes as peptides containing more than 50 amino acids. Proteins whose complete amino acid sequences are known are indexed as chemical substances from all patents and journals covered by CAS. The protein sequence is entered into the CAS sequence database, and is searchable and displayable on STN. Partial protein sequences are also indexed from selected journals. Each protein sequence is given a unique name based on controlled vocabulary, as well as author terminology, the species of origin, and additional information which may include strain/clone, gene, and subunit/isoform, etc., as applicable. Protein fragments may be prefixed with two numbers, relating to the range of amino acids represented; e.g., 1-124-Somatotropin (cattle). Replacement names, as for peptides, are used for analogs. If the range of amino acids cannot be based on a complete protein, fragment is included in the name. 208. Carbohydrates. Carbohydrate stereoparents are defined for indexing purposes as polyhydroxy acids, aldehydes, ketones, alkanes, and their derivatives, with a skeleton of five or more carbon atoms, more than half of which must be attached to oxygen (or another chalcogen) or nitrogen, and at least one of the chalcogen attachments must be by a single bond to a nonterminal carbon atom. At least half of the nonterminal carbon atoms must be asymmetric. Anomeric carbon atoms, whether terminal or non-terminal, are not counted in determining the number of asymmetric carbon atoms. Except for uronic and ulosuronic acids, the open chain is numbered to give the highest function the lowest possible locant. Illustrative structural diagrams related to current index entries will be found in the Chemical Substance Index for openchain forms and common cyclic forms of carbohydrate stereoparents. Stereoparents representing the following carbohydrates and their derivatives are employed as heading parents: Pentoses: Hexoses: 2-Hexuloses: Acids: Arabinose, Lyxose, Ribose, Xylose. Allose, Altrose, Galactose, Glucose, Gulose, Idose, Mannose, Talose. Fructose, Psicose, Sorbose, Tagatose. Ascorbic acid (¶ 224), Muramic acid, Neuraminic acid. Monosaccharides that exist in the open form are indexed at the stereoparents. Higher functions are expressed as substituents or in the modification. Derivatives of the cyclic forms are indexed at the highest function if a glycosyl radical can be used to express the sugar, which is ranked as a polyhydric alcohol unless a higher function, e.g., a nonglycosidic ketone or aldehyde, is expressed as a suffix. ¶ 208 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 are also named in the modification. Examples: D-Xylose 84 When a second stereoparent is represented in a structure, the parent of higher functionality is chosen in indexing. Configurational descriptors, D and L, are placed before stereoparent names, including monosaccharide semisystematic names (see below). Examples are D-Glucose and L-arabino-Hexose, 2-deoxy-. In the Fischer projections of the open forms, the carbon skeleton is displayed vertically, with locant “l” at the top. The D-series can then be recognized by the hydroxyl group to the right of the bottom nonterminal asymmetric carbon atom. Examples: CHO CHO H HO HO C C C CH2 L- Arabinose diethyl dithioacetal D-Xylose 2,3-diacetate 4,5-dibenzoate Cyclic hemiacetal forms of monosaccharides are indexed by inclusion in the name of a term indicating the ring size, if known; five, six, and sevenmembered rings, are denoted by “-furanose,” “-pyranose,” and “-septanose” suffixes. Two anomers, named “α” and “β,” result on ring formation, and these Greek letters are employed as anomeric prefixes, which are placed ahead of the configurational descriptors (D or L) in the name. Fischer projection H HO HO H OH C C C C OH H H OH OH H H CH2 OH D- Galactose Haworth projection HOCH2 O OH HO OH OH HC HC OH OH H OH O Configurational prefixes, derived from trivial aldose names, are used in semisystematic carbohydrate nomenclature; for one asymmetric carbon atom, e.g., >CHOH, >CHOCH3, >CHNH2, glycero is the prefix used (with D or L as described above); with two, erythro and threo; with three, arabino, lyxo, ribo, and xylo; with four, allo, altro, galacto, gluco, gulo, ido, manno, and talo. (The centers need not be on neighboring carbon atoms.) For more than four consecutive centers, combinations of these terms are used. Examples (“X” is the group with the lowest-numbered carbon atom): X X X X H C Y D- glycero- HO C ≡ HC HC CH2OH α-D-Glucopyranose The following examples show the derivation of names for ketoaldoses when the ring closure involves (a) the aldehyde, and (b) the keto function. HO H C CH2 CH2 H HO H H HO C CH2 C Y HO OH HO C C Y HOCH2 H O OH OH OH OH O H HO C Y (a) α-D-xylo-Hexopyranos-4-ulose L- erythro- In choosing a monosaccharide stereoparent name (when such a choice is necessary), (a) the oxo (or higher) function is numbered low (except the carboxyl group in uronic and ulosuronic acids); (b) the name appearing earliest alphabetically is chosen; (c) “D” is preferred to “L”; (d) the anomeric prefix “α” is preferred to “β”; (e) lowest locants for substituents are employed; (f) the lowest locant is used for the first-cited substituent. Systematic carbohydrate names, employed for monosaccharides other than those with trivial names, are based on stem names which express the size and function; the stem names for open-chain aldoses of five or more carbon atoms are Pentose, Hexose, Heptose, Octose, Nonose, etc.; corresponding ketose stems are Pentulose, Hexulose, etc. (Additional terms are used to indicate ring size if necessary; see below.) The stem names are preceded by stereochemical descriptors. 2-Hexuloses have trivial names (see above); other ketoses are named systematically, e.g., L-erythro-2-Pentulose. For meso-forms, the Dand L- configurational symbols are not needed; e.g., erythro-3-Pentulose. Diketoses have names of the type D-threo-2,4-Hexodiulose; ketoaldoses have “-osulose” names such as D-ribo-Hexos-3-ulose; dialdoses have names such as D-gluco-Hexodialdose; chalcogen analogs are indexed by use of thio, etc., prefixes, e.g., D-Glucose, 1-thio-; replacement of hydroxyl by hydrogen is denoted by “deoxy” terms. Substitution on carbon with prior removal of a hydroxyl group requires citation of “deoxy” and the substituent prefix in alphabetic order, e.g., D-Glucose, 2-(acetylamino)-2-deoxy-. When the existing hydrogen is substituted on a carbon atom already carrying an oxygen (or other chalcogen) or nitrogen group in the open or cyclic forms, the italic capital letter C is employed, e.g., D-Ribose, 3-C-(nitromethyl)-. When both the hydrogen and hydroxyl are replaced by nonchalcogen, nonnitrogen substituents, the stereochemistry is expressed by a Sequence Rule descriptor at the systematic saccharide name, e.g., D-ribo-Hexose, 3-bromo-3-chloro-3-deoxy-, (3S)-. Substitution of hydrogen on a hydroxyl group of a carbohydrate is denoted by “O” locants (or by “S”, etc., if chalcogen replacement has also taken place). Examples: D-Mannose, D-Glucose, D-Glucitol, O HO OH HOCH 2 (b) α - L - xylo - Hexos -2 -ulo -2,5 furanose CHO More complicated cases, e.g., cyclic forms of dialdoses and higher ketoses, are named in accordance with rules (lowest locants for the keto group, alphabetically preferred configurational prefixes, etc.) already described. Locants, e.g., “-6,10-” are inserted before the ring-size descriptor in the name, and “α” or “β” is also cited if the anomeric carbon is numbered lower than the reference carbon atom in the ring being formed, otherwise R or S is used. Nitrogen analogs of cyclic sugars are named systematically. Intramolecular anhydrides are denoted by terms such as “1,5-anhydro” in which the locants define the pair of hydroxyl groups involved. The sulfur analogs are named with “dideoxy-epithio” terms. Intermolecular anhydrides are polysaccharides (below); intermolecular dianhydrides are named by citing the word “dianhydride” after the name(s) of the parent monosaccharides (an aldose precedes a ketose); two pairs of locants define the positions of the anhydride linkages. Example: 6 HOCH2 O O 2 5 HO CH2 3 HO 1 1´ CH2 2´ O HO 3´ 4´ 5´ O HO β-D-Fructofuranose β-D-threo-2pentulofuranose 1,2´:2,1´ - di anhydride Carbohydrate acids are named by characteristic suffixes, as follows: The stems of aldaric, aldonic and uronic acid names are derived from trivial (common) aldose names whenever possible. Acids containing a keto function are named from the systematic stem names. Acid halide, amide, and nitrile names are derived as usual. Esters, hydrazides, salts, and lactones are expressed in the modification. Lactams are named systematically (¶171). Examples: D-Gluconoyl 2,3,4,5,6-penta-O-methyl- 2-S-ethyl-2-thio1-O-ethyl-1-C-(phenylamino)- Cyclic acetals employ bivalent radicals with “O” terms, e.g., D-Ribose, 2,3:4,5-bis-O-(1-methylethylidene)-. Oximes and hydrazones are expressed in the modification, osazones similarly as dihydrazones of osuloses. Hydrates, acetals, hemiacetals and esters chloride 85 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 1 CO2H 1 CO2H 2 C=0 1 CHO ¶ 208 α-D-Glucopyranuronamide, 1,1´-iminobis[1-deoxy( C HOH ) x x C O2H ( C HOH ) x C H2OH ( C HOH ) C H2OH -onic acid 1 CHO 2 C=O -ulosonic acid -uronic acid 1 CO2H 1 CO2H 2 C=O ( C HOH ) x C O2H ( C HOH ) x C O2H ( C HOH ) x C O2H Glycosides are mixed acetals derived by replacement of the hydrogen atom on the anomeric hydroxyl group of a saccharide by a group derived from an alcohol or phenol. Glycoside heading parents, e.g., α-D-Ribofura-noside, are employed. In the inverted part of the heading, the radical derived from the alcoholic or phenolic aglycon is cited, followed by a space. Then any substituents of the saccharide are expressed in the usual way. When functions higher than the saccharide (which is normally a polyol) are present in the aglycon, a heading parent which expresses the greatest number of highest functions is chosen, provided that an appropriate glycosyl radical name can be employed to express the saccharide as a substituent. When the functionality is equal in the two portions of the molecule, the stereoparent is preferred. Glycoside parents are also derived from uronic acids and ulosonic acids, e.g., α-D-Mannopyranosiduronic acid; α-D-arabino-2-Hexulofuranosidonic acid. Examples: HOCH2 -ulosuronic acid L-Ribonic -aric acid -ulosaric acid O OH Br HO OMe acid γ-lactone β-D-Mannopyranoside, methyl 2bromo-2-deoxy- The trivial names Muramic acid and Neuraminic acid are used for the structures shown below; the acyl radicals muramoyl and neuraminoyl, and the glycosyl radicals muramosyl and neuraminosyl, are also employed in indexing. (Isomuramic acid is treated similarly; it is the muramic acid (S)-epimer about the carbon atom bearing the carboxyl group.) Examples: AcOCH2 O α - D - erythro - Hexopyranosid -3 ulose, methyl 2-deoxy4,6-diacetate OMe H2N HOCH2 O OCHMeCO2 H HO OH NH2 OH H C OH H C OH CH2 OH O OH CO2H AcO O HOCH2 O SMe α-D-Ribofuranoside, methyl 1-thioOH α-Muramic acid (the (R)-epimer) β-Neuraminic acid HO Glycosyl radicals derived from trivially and systematically named saccharides by removal of the anomeric (hemiacetal) hydroxyl group have the suffix “-osyl,” e.g., β-D-mannopyranosyl (if the ring size is known), D-mannosyl, αD-arabino-hexopyranos-2-ulos-1-yl. Uronic acid radicals are derived by replacing the “-ic acid” by “-osyl,” e.g., β-D-glucopyranuronosyl; acid derivatives, e.g., uronamides, yield “-uronamidosyl” radicals, etc. The following stereochemical and ring size assumptions are made when an author does not completely define a glycosyl radical: FOR galactosyl glucosyl mannosyl xylosyl L-fucosyl D-fucosyl Glycosides of ring systems are indexed at the saccharide headings unless the aglycon contains a higher function or the glycosyl attachment is at a nitrogen atom. C-Glycosides (glycosyl derivatives with carbon-carbon bonds) of ring systems are indexed at the higher function. Examples: D-Glucitol, 1,5-anhydro-1-C-phenyl- (1R)4H-1-Benzopyran-4-one, 8-β-D-glucopyranosyl-2-phenylA naturally occurring glycoside is indexed at the systematic (or stereoparent) name if the structure, including the ring-size of the saccharide, is known, whether or not all the stereochemistry has been elucidated. (A “glucoside” is assumed to be the β-D-glucopyranoside, a “rhamnoside” the 6-deoxy-α-Lmannopyranoside.) N-Glycosyl derivatives of heterocycles are usually indexed at the heterocycle names (see also Nucleosides and Nucleotides, ¶ 210), but a saccharide containing an expressed aldehyde or higher functional suffix is preferred. Examples: ASSUME D-galactopyranosyl D-glucopyranosyl D-mannopyranosyl D-xylopyranosyl 6-deoxy-L-galactopyranosyl 6-deoxy-D-galactopyranosyl NH 2 rhamnosyl fructosyl apiosyl 6-deoxy-L-mannopyranosyl D-fructofuranosyl D-apio-β-D-furanosyl 5´ 1 6 7 5 N 3 N N 9 HOCH2 4´ 3´ N 4 O 1´ 2´ Note that no assumption is made for fucosyl when the absolute stereo is not indicated. Glycosyl halides, isocyanates, etc., without functions higher than a polyol in the unsubstituted saccharide have names containing the “-osyl” radical; otherwise the heading parent expresses the higher function. Examples: α-D-Mannopyranosyl bromide β-D-Glucopyranuronic acid, 1-chloro-1-deoxyGlycosylamines are named by similar principles. Examples: α-D-Glucopyranosylamine 3H-Purin-6-amine, 3-β-D-ribo furanosyl- HO OH O S N Me O2 C HO OH O O β-D-Galactopyranuronic acid, 1deoxy-1-(2,5-dioxo-3-thiazoli dinyl)-, methyl ester OH ¶ 208 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 86 Alditols are polyhydric alcohols derived mainly by reduction of aldehydes. They are named by changing the suffix “-ose” to “-itol.” Since the end groups are alike, they are more symmetrical than saccharides; the preferred heading parent is the one in which the trivial name (or the configurational prefix (erythro, etc.) of a semisystematic name) and then the configurational descriptors (D and L) expresses the lowest alphabetic order. Hence Gulitol is cross-referred to Glucitol, and D-glycero-L-gulo is preferred over D-glyceroD-ido. Lowest locants for substituents are considered only after the heading parent has been determined. Example: CH2OH MeO H H HO C C C C H OH OH H H CH2OH C C C C OH H H OMe D-Galactitol, 5-O-methyl- (not L-Galactitol, 2-O-methyl-) 209. Cyclitols are cycloalkanes in which a hydroxyl group is attached to each of three or more ring atoms. Cyclitols of the cyclohexane series constitute the inositols; those that contain at least five asymmetric centers in the ring, of which at least three are directly bonded to oxygen (or another chalcogen) or nitrogen, are given Inositol stereoparent names; the others are named systematically as cyclohexanepolyols. Relative stereochemistry is expressed by special italicized configurational prefixes. The eight Inositol stereoparents, arranged according to the number and position of hydroxyl groups on the same side of the cyclohexane ring (as indicated by the numerical locants, which are not used in indexing) are: cis-Inositol epi-Inositol allo-Inositol myo-Inositol muco-Inositol neo-Inositol chiro-Inositol scyllo-Inositol (1,2,3,4,5,6) (1,2,3,4,5) (1,2,3,4) (1,2,3,5) (1,2,4,5) (1,2,3) (1,2,4) (1,3,5) ≡ HO HO H CH2 OH CH2 OH The meso alditols (Ribitol, Xylitol, Allitol, and Galactitol) do not require D or L unless they are substituted unsymmetrically, in which case the D-form is chosen. Higher chemical functions than the alditol are expressed as substituents of the alditol parent. Branched-chain monosaccharides are generally named as derivatives of the linear saccharides, selecting first the highest function and then the longest chain, but the trivial name Apiose is used. Example: 1 CHO Choice of a preferred index name for an inositol derivative depends on (a) the alphabetically preferred configurational prefix in the order: allo, chiro, cis, epi, muco, myo, neo, scyllo; (b) the preferred configurational descriptor (D over L); (c) the lowest set of locants for substituent prefixes (¶ 137). The configurational descriptor D or L may be determined by numbering the hydroxyl groups (or replacement groups) which lie on one side of the ring beginning at each possible “position 1.” If the groups, e.g., the 1,2,4-groups in chiro-Inositol, are up when numbering clockwise, or down when numbering counterclock-wise, the descriptor is L; if the groups are up in numbering counterclockwise or down in numbering clockwise, the descriptor is D. The D-stereoparent is chosen regardless of high locants for substituent prefixes. The D and L descrip-tors are used only when optical activity is present and can be determined from the original document. Example: HO OH 1 6 H 5 2 3 C C OH OH 4 D-Apiose OH 1 6 OH HOCH 2 CH2 OH HO OH OH HO OH HO OH Olefinic monosaccharides are expressed by “en” in the stereoparent. Destruction of the anomeric center leads to an anhydro unsaturated alditol with the multiple bond assigned the lowest possible locant after the alphabetic choice (D before L, α before β) has been made. Geometrical isomerism about a double bond, when known, is indicated by E and Z descriptors. Examples: D-threo-Hex-2-enose, HO L-chiro-Inositol D-chiro-Inositol 2-(acetylamino)-2,3-dideoxy(2Z)- 9H-Purin-6-amine, 9-(2,3-dideoxyβ-D-erythro-hex-2-enopyranosyl)D-xylo-Hex-1-enofuranosylamine, 2-deoxy-N-phenylOligosaccharides of known structure are given carbohydrate names which express the monosaccharide content. The open-chain form is used in naming reducing oligosaccharides in the absence of anomeric prefixes or contrary derivative information. Trisaccharides and higher members are named by use of “arrow” nomenclature, in which arrows and locants indicate the direction and position of linkages from anomeric carbon atoms to hydroxylic carbon atoms. The reducing monosaccharide unit is named as the stereoparent. Other substituents of the parent are named last. Examples: Lactose. Sucrose. Cellotriose. Stachyose. See D-Glucose, 4-O-β-D-galactopyranosylSee α-D-Glucopyranoside, β-D-fructofuranosyl See D-Glucose, O-β-D-glucopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→4)See α-D-Glucopyranoside, β-D-fructofuranosyl O-α-D-galactopyranosyl-(1→6)-O-α-Dgalactopyranosyl-(1→6)- Ethers are named as O-derivatives; chalcogen analogs are expressed by “thio,” etc., in the inverted part of the heading. Esters are expressed by modification terms, e.g., “hexaacetate.” Glycosides are indexed at the Inositol stereoparent with O-glycosyl substituent prefixes. 1,2,3,4,5-Cyclohexanepentols (quercitols) are indexed at the alphabetically preferred Inositol parent by use of a “deoxy” prefix, and D or L determined as described above, e.g., D-chiro-Inositol, 2-deoxy- (not D-chiro-Inositol, 5-deoxy; not D-muco-Inositol, 2deoxy-; not L-muco-Inositol, 1-deoxy-). Replacement of one, two, or three hydroxyl groups, with retention of configu-ration, is expressed by “deoxy” terms and appropriate radicals. The capital italic letter C is used to denote replacement of hydrogen on a carbon atom to which a hydroxyl group is also attached, e.g., scyllo-Inositol, 1-C-methyl-. Inosamines and their N-acyl (including carboxy) derivatives are usually indexed at such names as neo-Inositol, 2-amino-2-deoxy-, but Streptamine is the stereoparent for 1,3-diamino-1,3-dideoxy-scyllo- inositol and derivatives. Example: H2NC( =NH)NH NHC ( =NH)NH 2 HO OH HO OH Streptamine, N,N´-bis(aminoiminomethyl)- Inosose is the stereoparent for 2,3,4,5,6-pentahydroxycyclohexanone stereoisomers. Example: HO HO HO 6 1 Polysaccharides are often indexed at common names, e.g., Agar, Amylopectin, Cellulose, Starch. Homoglycans (polysaccharides derived from one type of sugar residue) are named by converting the “-ose” suffix of an aldose or ketose, or the “-ic acid” of a glycuronic acid, to “-an,” e.g., β-DMannan, (1→4)-; L-Arabinan; D-Glucuronan. Heteroglycans contain more than one kind of saccharide; the name, e.g., Glucuronoarabinoxylan, expresses the saccharide with the higher chemical function first; if the functions are alike, longer chain and then alphabetic order decide. Esters and most other derivatives are cited in the modification. Synthetic homopolymers and copolymers are indexed by polymer nomenclature, e.g., L-Arabinose, homopolymer. O OH epi-3-Inosose (not muco-3-Inosose) HO 87 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Example: O 7 ¶ 211 210. Nucleosides and Nucleotides are hydrolytic products of nucleic acids; chemically, nucleosides are N-glycosyl derivatives of heterocyclic bases, principally purine and pyrimidine, and nucleotides are esters of nucleosides with phosphoric acid and polyphosphoric acids. The bases are named systematically, with the tautomerism resolved for indexing purposes in favor of highest expressed function, etc. (¶ 122). Trivial Name Adenine Cytosine Guanine Hypoxanthine Thymine Uracil Xanthine Index Name 9H-Purin-6-amine 2(1H)-Pyrimidinone, 4-amino6H-Purin-6-one, 2-amino-1,7-dihydro6H-Purin-6-one, 1,7-dihydro2,4(1H,3H)-Pyrimidinedione, 5-methyl2,4(1H,3H)-Pyrimidinedione 1H-Purine-2,6-dione, 3,7-dihydro- HN H2N N 3 5 N N 9 4 5´ AcOCH2 4´ 3´ Guanosine 3´-(trihydrogen diphosphate), 2´-deoxy5´-acetate 1´ 2´ O OP(O)(OH)OP(O)(OH)2 P P´ Trivial names for seven common nucleosides and the related nucleotides are employed as stereoparents; these nucleosides are: Purine derivatives Adenosine Guanosine Inosine Xanthosine Pyrimidine derivatives Cytidine Thymidine Uridine Coenzyme A is employed as a stereoparent for adenosine 5´-(trihydrogen diphosphate) 3´-(dihydrogen phosphate) P´-[(3R)-hydroxy-4-[[3-[(2-mercaptoethyl)amino]-3-oxopropyl]amino]-2,2-dimethyl-4-oxobutyl ester; functional derivatives, notably esters such as “S-acetate,” are also indexed at this stereoparent. Esters and molecular addition compounds of nucleoside and nucleotide stereoparents, including “-ylic acids,” with nonstereoparents are indexed at the stereoparents regardless of functionality. Example: Inosine 5´-(trihydrogen diphosphate) 2´-(dihydrogen phosphate), P´ → 5´-ester with 3-(aminocarbonyl)-1-β-D-ribofuranosylpyridinium, inner salt Oligonucleotides contain not more than eight nucleotide units connected by phosphoric acid residues. Higher-molecular-weight compounds are indexed as polynucleotides (see Polymers ¶ 222) or at the headings DNA or RNA. Phosphate links attached to the preferred stereoparent of an oligonucleotide form parts of “-ylyl” radical substituents. The heading parent is attached to the rest of the nucleotide chain at its 5´position. Arrows are employed with locants, as in oligosaccharide nomenclature (¶ 208), to indicate progression and points of attachment on saccharide residues beginning at the end of the chain furthest from the preferred stereoparent. Esters and substituents of “-ylyl” radicals are named as substituents without regard to higher functions. Nonnucleotidylyl esters of the stereoparent are expressed in the modification. When a cyclic ester is part of the polynucleotide linkage, the locants for the ester are separated by a hyphen, and the arrow to the point of attachment follows in the usual way, e.g., Adenylic acid, adenylyl-(2´-3´→5´)-. Example: The seven stereoparents (above) are heading parents for derivatives, including N-acyl and N-carboxy derivatives, e.g., Adenosine, N-acetyl-; Cytidine, N-(ethoxycarbonyl)-. When a chemical function higher than carboxamide (¶ 106), except N-carboxy, is present, an index parent which expresses it is chosen, unless lack of a suitable radical precludes expression of the nucleoside residue as a substituent prefix (this occurs when the higher function is attached to the saccharide at any position other than “1´”). Replacement of oxygen in the saccharide moiety or on the heterocycle by sulfur is expressed by a “thio” prefix, and the regular methods of carbohydrate nomenclature (¶ 208) are employed for other saccharide modifications, including ester formation other than phosphates. Examples: Me 2 N 6 1 N 7 5 N N 3 N N9 4 5´ Adenosine, 3´-(acetylamino)-3´deoxy-N,N-dimethyl- HOCH2 4´ O 3´ 2´ 1´ 1 6 NH 2 7 5 N N 3 N N9 AcNH OH 4 5´ HO(CH2)2OP(O)(OH)OCH2 NHMe Cl CO( CH2 ) 2 6 5´ 1 N N 3 O 5 -Pyrimidinepropanoyl chloride, 1,2 -dihydro -4 -(methylamino) 2 -oxo -1 -β -D -ribofuranosyl (not Cytidine, 5-(3-chloro-3-oxopropyl)-N-methyl-) 4´ 3´ O 2´ 1´ O 7 O OH 5´ 9 N N 5 1 6 NH NH2 HOCH2 4´ 3´ MeOP(O)OCH2 4´ 1´ 3´ 2´ 4 N 3 O O 1´ 2´ HO HO OH OH Nucleotides are indexed at stereoparents descriptive of the type and position of the phosphate residue on the sugar moiety. Esters with phosphoric acid, H3PO4, are “-ylic acid” stereoparents. Each isomer has its own heading, e.g., 5´-Adenylic acid for the 5´-(dihydrogen phosphate) of Adenosine. When more than one such acid residue is present, the lowest locant is chosen for the stereoparent, e.g., 3´-Adenylic acid, 5´-(dihydrogen phosphate). Cyclic phosphates are expressed in the modification at the nucleoside name by such phrases as “cyclic 3´,5´-(hydrogen phosphate).” Nucleoside esters with unsubstituted linear polyphosphoric acids are indexed at stereoparents which express the complete ester name, e.g., Guanosine 3´-(trihydrogen diphosphate). An unspecified isomer is assumed to be the 5´-isomer. Di- and triesters with the same acid are indexed at the lowest numbered isomer heading. Substituted derivatives and esters with nonphosphorus acids are named like those of the nucleotides. Guanosine, 5´-0 -[hydroxy(2-hydroxyethoxy)phosphinyl]-P methyladenylyl-(3´ →5´)- Intermolecular cyclic nucleotides are named like the linear compounds, but with the term “cyclic nucleotide” in the modification. 211. Steroids are cyclopenta[a]phenanthrene derivatives that are indexed as stereoparents (¶ 202) at trivial names that imply stereochemistry. The following steroid numbering system is employed: ¶ 211 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 88 29 Me 21 28 CH 22 2 27 Me Me Me Me H H H H H O O Br Me Me 19 1 18 20 17 Me 24 26 25 Me Me 9 10 11 H 13 14 8 H H H 4 6 HO H When two methyl groups are present at the 4-position, as well as one at the 14-position, along with a 1,5-dimethylhexyl substituent at position 17, the compound is indexed as a terpene stereoparent (¶ 212); otherwise the steroid or terpene stereoparent is employed that requires least modification. The hydrogenated ring system without substituents is Gonane; Estrane has a methyl group only at the 13-position; the compound with only a 10-methyl group is named as 18-Norandrostane. The following stereoparents are derivatives of Androstane (hexadecahydro-10,13-dimethyl-1H-cyclopenta[a]phenanthrene) with various side chains at the 17-position: -CH2Me -CHMePr -CHMe(CH2)3CHMe2 -CHMe(CH2)2CHMeCHMe2 -CHMe(CH2)2CHEtCHMe2 Pregnane Cholane Cholestane Ergostane Stigmastane Spirostan-3-ol, 24-bromo(3β,5β,24R,25R)-(configurations for added stereochemistry at C-3 and C-24 are indicated: there is no modified stereochemistry) The implied configurations in all cases are 8β,9α,10β,13β,14α. The configuration at the 5-position, when known, is cited as added stereochemistry in the modification. Pregnane is 17β; Cholane and Cholestane are 17β,20R; Ergostane is 17β,20R,24S; Stigmastane is 17β,20R,24R. Unsaturation in steroids is expressed by “en” and “yn” infixes, e.g., Estra-1,3,5(10)-triene; Androst-1-en-16-ol, (5α)-. The first example requires two locants for the last cited double bond; this situation is avoided where possible, with steroids containing benzenoid rings, by rearrangement of bonds; e.g., Gona-5,7,9-triene (not Gona-5(10),6,8-triene). Cyclosteroids contain an additional ring formed by a valence bond between two existing ring positions or between a ring position and an angular methyl group or side-chain atom. They are indexed at such stereoparents as 3,5Cyclopregnane and 9,19-Cycloandrostane. Bufanolide and Cardanolide are stereoparents with a δ-lactone and a γ-lactone ring, respectively, attached to the 17-position of Androstane. The configurations are as for Cholane except for 14β instead of 14α. When a carboxylic acid or higher function is present the lactone ring is opened and named in the modification. Example: O O Elimination of an acyclic carbon atom (or methyl group) from a steroid is expressed by the prefix “nor” with the locant for the carbon removed; (but 21-Norpregnane is indexed at Androstane, 17-methyl-). Elimination of one or two carbon atoms from the C-17 side chain of C27 and larger steroids may be expressed by “nor” and “dinor,” unless a smaller stereoparent is thereby obtained; e.g., 21,27-Dinorcholestan-26-oic acid; 26,27-Dinorcholestane; but Cholane-24-carboxylic acid (not 26,27-Dinorcholestan-25-oic acid). Removal of C-18 and C-19 by “nor” terms is independent of treatment of the C-17 side chain; hence 18,19-Dinorpregnane (not Gonane, 17-ethyl-). Ring modification expressed by “nor”, “homo” and “seco” are no longer permitted. Such substances are named systematically. Replacement (“a”) nomenclature (¶ 127) is no longer used for heterosteroids, e.g., 2-thiaandrostane, and 3-aza-A-homoandrostane, are now given systematic names. Steroidal alkaloids containing exocyclic nitrogen are indexed at steroid stereoparents. Thus Irehine is cross-referred to Pregn-5-en-3-ol, 20-(dimethylamino)-, (3β,20S)-. Kurchi alkaloids are named as derivatives of the stereoparent Conanine; implied configurations are the same as for Pregnane, with the addition of 20β. Example: Me N Me H H 2N H H Me H Con-5-enin-3-amine (3β)- The solasodine-tomatidine and solanidine groups of Solanum alkaloids are indexed at Spirosolane and Solanidane stereoparents, respectively. Example: H Me Me Me H H HO H H H N Me Me HO2C H HO HO H H OH 24-Norchol-20(22)-ene-19,23-dioic acid, 3,5,14,21-tetrahydroxyγ-lactone, (3β,5β,14β)- Solanid-5-en-3-ol (3β)-(When C-5 is asymmetric, its configuration, when known, is cited.) Furostan is a stereoparent which represents 16β,22-epoxycholestane; this has a furan ring fused to the steroid system in the 16,17-position. Spirostan is a 16,22:22,26-diepoxycholestane derivative. Configurations at the 5-, 22-, and 25-positions of furostan and at the 5- and 25-positions of spirostans are expressed in the modifications if known. Examples: CH2 OH Me Me Me H H H H H H O (CH2)2 C- - H Me Furostan-26-ol (5α,20β,22α,25S)-(configuration at C-20 is reversed from that shown in the stereoparent diagram) Veratrum alkaloids are indexed, according to type, at the stereoparents Veratraman and Cevane. Buxus alkaloids are indexed at such headings as 9,19-Cyclopregnane. Radicals derived from steroid stereoparents are employed when the highest function is present in a nonsteroid part of the molecule (except the esters, semicarbazones and additional compounds are always indexed at the stereoparents (¶ 202)). Radical names are formed in the usual way, and the free valency can be at an acyclic atom; e.g., estra-1,3,5(10)-triene-17-yl, cholest-4en-26-yl. No radical names are formed from cardanolides or bufanolides. Configurations are cited ahead of the entire substituted radical; e.g., [(3β,5α)-3-hydroxyandrostan-5-yl]-. For acetals of steroids, see ¶ 202. Steroids with -O- and -OO- bridges are indexed by use of “epoxy” and “epidioxy” substituents at the stereoparents. Steroid stereoparents may be adopted as components of spiro systems (¶ 156), e.g., Spiro[androst-4-ene2,1´-cyclopropan]-3-one. Fused steroid names are used on a restricted basis. The steroid component is named first when fusion is to a heterocycle; the reverse order occurs with less preferred carbocycles. Each system retains its own numbering and the nonsteroid is given primed locants. When saturation is expressed at positions common to both components, steroid locants are cited if possible. 89 Examples: Me H Me H H H H Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 212 3´H-Cyclopropa[2,3]androsta-2,4diene, 2,3-dihydro-, (2α,3α)OH Me Abnormal configurations are expressed by “α” or “β” at angular carbon atoms in ring systems, and by “R” and “S” when there is inversion on a bridge or side-chain. Additional stereochemistry produced by substitution is expressed similarly. All terms cited with a stereoparent are considered to be absolute, not relative. The geminate methyl groups of triterpenes have no implied configuration associated with the locants; “α” or “β” is cited when substitution in the methyl groups makes this necessary. Because lowest locants are assigned to principal groups, in accordance with general systematic nomenclature, the author’s numbering may be changed in indexing, especially with a symmetrical stereoparent such as Gammacerane. Example: OH 1 11 Me H N H H H Me H 18 13 14 17 H H 10 H 4 24 23 Me Me Me 27 9 Me 8 25 6 N 2´H-Androst-2-eno[3,2-c]pyrazol17-ol, (5α,17β)- Me 29 Me 30 Me H 212. Terpenes contain repeating isopentane units: C ( — C - C - C - C— ) n Gammacer-15-en-3-ol, (3β)- (not Gammacer-6-en21-ol, (21α)-) Mono-, sesqui-, di-, sester-, tri-, and tetraterpenes contain two, three, four, five, six, and eight such units; tetraterpenes are usually called carotenes (see below). Most mono-, sesqui-, and diterpenes are indexed by the principles of systematic substitutive nomenclature; stereoparents are employed for terpenes that contain four or more rings, or possess three or more elements of stereochemistry, at least one of which is associated with a bridged or side-chain center, or a center in a ring of twelve or more members. Examples: Me CHMe2 “Friedo,” preceded by D, has been used to indicate D:A, D:B, or D:C as prefixed to pentacyclic triterpene stereoparents that angular methyl groups have shifted from their normal positions. These names are no longer used, and these substances are named as derivatives of other triterpenes. The prefix “neo-” preceded by an italicized capital A indicates that ring A has undergone a rearrangement. These names are no longer used. In the gammacerane skeleton, A´-Neo- is used. H H 22 28 17 H 13 14 19 18 H Me 29 21 22 CH — Me Me 29 28 Me Me 30 Me 30 Me Me 27 27 OH Cyclohexanol, 3-methyl-2-(1methylethyl)-, (1S,2R,3R)- (o-Neoisomenthol) Normal arrangement A´ - Neo- Me 1 6 7 5 Me Me Bicyclo[3.1.1]heptane, 2,6,6-trimethyl- (Pinane) Me 1 6 O Me Me 7 4 Bicyclo[2.2.1]heptan-2-one, 1,7,7trimethyl- (Camphor) Me H The prefix “cyclo” indicates a valence bond forming an extra ring, e.g., in 9,19-Cyclolanostane a “fused” cyclopropane ring is formed. Principal groups are expressed as “-oic acid,” “-al,” “-one,” “-ol,” etc., by the procedures of general substitutive nomenclature. Terpene radicals are formed in the usual way. Configurational terms are placed ahead of the complete radical (cf. Steroids, ¶ 211). Lactones of triterpene acids are indexed at the acid names; cyclic acetals are likewise expressed in the modification at stereoparent headings. Carotenoids comprise carotenes (hydrocarbons) and xanthophylls (their oxygenated derivatives) in which eight isoprene units are joined in such a manner that the arrangement is reversed at the center of the molecule, whereby the two central substituent methyl groups are in 1,6-relationship and the remaining methyl groups in 1,5-relationship. The class also includes some rearranged and degraded compounds, but excludes Retinol and related C20compounds (see below). General entries are found at Carotenoids in the General Subject Index. Specific substances are indexed at Carotene: 17 16 1 10 5 Me H CHMe2 Naphthalene, decahydro-1,6-dimethyl-4-(1-methylethyl)-, (1S,4S,4aS,6S,8aS)- (Cadinane) Me Me Me 19 Me 15 20 Me 18 18´ Me Me 2CH H 10´ Me 5´ Me Naphthalene, decahydro-1,4a-dimethyl-7-(1-methylethyl)-, (1R,4aR,7R,8aS) (Eudesmane) 15´ Me 20´ Me 19´ Me Me 16´ 17´ 1´ The stereoparent Trichothecane, a sesquiterpene “epoxide,” is used in indexing, and other derivatives of sesquiterpenes and diterpenes may be used as stereoparents when they meet the criteria. Gibbane is a partially stereospecific stereoparent employed in naming gibberellic acid derivatives. Two tetracyclic diterpene stereoparents are Kaurane and Atisane. Cyclic triterpenes include Gammacerane, Lanostane, Lupane, Oleanane, and Ursane. Each dotted curved line represents two double bonds or their equivalent; thus, individual compounds may have acyclic end groups with two double bonds, or terminal cyclohexenyl groups, or one of each. By extension, Carotene is used as the stereoparent representing dihydro and tetradehydro derivatives which possess cyclopentyl and phenyl end-groups. Two Greek letter prefixes on the Carotene stereoparent, cited in (Greek) alphabetical order, are employed to express the terminal structures of specific compounds: ¶ 212 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 90 17 16 1 17 16 17 16 Me Me R 6 Me 1 Me R 6 Me Me R Me 18 Me 18 Me 18 Ψ β ε 16 17 1 6 5 Me 17 16 Me 6 16 Me CH2R Me Me 18 Me 17 1 R Me R Carotenoids with diosphenol end-groups are indexed as the keto tautomers; e.g., β,β-Carotene-3,3´,4,4´-tetrone. For carotenoids with identical end groups, lowest locants are assigned to the principal groups, if present, and then to prefixes; e.g., ε,ε-Carotene-2,3´-dione, 2´-methoxy- (not ε,ε-Carotene2´,3-dione, 2-methoxy-). “Retro” carotenes have undergone a shift of the alternating single-double bond system by one position. A prefix such as “4,7´-retro-” is applied to the stereoparent to express this situation; the first cited locant shows where a proton has been gained, the second, where a proton has been lost. “Apo” carotenes names are no longer used. Oxidative degradation products of carotenes are named at retinol, retinoic acid, etc., or systematically. Stereochemistry of carotenoids is of two types. The geometrical configuration around double bonds is implied by the stereoparent stem Carotene to be all-trans. Abnormal configuration at one or more positions is indicated in the modification by terms such as “15-cis-.” Absolute configuration at chiral centers is expressed by “R” or “S.” Example: 19 20 Me 18 Me 18 Me Me 11 15 κ ϕ χ Me 17 O 16 Me 1 5 6 10 α-Carotene is indexed at β,ε-Carotene, β-carotene is β,β-Carotene; γ-carotene is β,Ψ-Carotene; and lycopene is Ψ,Ψ-Carotene. The plain (unprimed) locants are assigned to the end of the molecule related to the first-cited Greek letter. “Hydro” and “dehydro” express addition and subtraction of hydrogen; oxygen functions are expressed by “-oic acid,” “-al,” “-one,” “-ol,” etc., in the usual way. Oxygen bridges are indicated by “epoxy,” it being understood that the oxygen replaces one hydrogen atom at each bridgehead; thus, an “epoxide” is an epoxy-dihydro derivative. Example: Me 18 OH OH 18´ 17´ 1´ 6´ Me Me Me 16´ 15´ O Me 20´ Me 19´ 17 16 1 6 19 20 Me Me Me 7 11 Me 15 κ,κ-Carotene-6,6´-dione, 3,3´-dihydroxy-, (3S,3´S,5R,5´R)- O 5 HO Retinol and its relatives are indexed at stereoparent headings. 19 Me 18 20 Me 5´ OH 17 16 1 Me 7 11 Me 15 Me Me 6 O 15´ 11´ 7´ 6´ 1´ CH=CHC=CHCH=CHC=CHCH2OH Me 20´ Me 19´ Me 18´ Me 17´ Me 18 Retinol (stereoparent) β,β-Carotene-3,3´-diol, 5,6:5´,6´-diepoxy-5,5´,6,6´-tetrahydroAddition of water (H, OH) or methanol (H, OCH3) to a double bond is expressed by “dihydro-hydroxy” and “dihydro-methoxy.” When the “-ol” suffix can be used only for some of the hydroxy groups, the “dihydro-hydroxy” method is employed for all. Illustrative diagrams for Retinol and Retinoic acid appear in the Chemical Substance Index. Vitamin A1 is indexed at Retinol; Vitamin A2 at Retinol, 3,4-didehydro-. The hydrocarbon “Retin” is used as a stereoparent, as well. The all-trans configuration is assumed; if abnormal stereochemistry is reported, it is expressed in the modification by terms such as “13-cis-”. 91 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 F. SPECIALIZED SUBSTANCES ¶ 215 Introduction Alloys Coordination compounds Dyes Elementary particles Enzymes ¶ 213 214 215 216 217 218 Inorganic compounds Isotopes Mixtures Polymers Porphyrins and Bile pigments Vitamins ¶ 219 220 221 222 223 224 213. Introduction. The special classes of chemical substances discussed in this section exclude those natural products and their derivatives, largely indexed at stereoparents, which were the subject of the previous section. The topics covered here fall into three groups: inorganic (alloys, coordination compounds, elementary particles, and general inorganic compounds); biological (enzymes, porphyrins and bile pigments, and vitamins); and special subjects not chemically related to any particular class (dyes, isotopes, mixtures, and polymers). The arrangement is alphabetic. 214. Alloys, including those with nonmetallic and gaseous components, are indexed and registered by CAS as specific chemical substances. The percentage composition is expressed in the modification in descending order of abundance of metals, either as individual round numbers or as ranges. Components present in amounts below 0.1% are generally ignored. The metal in greatest amount is indexed at an “element alloy base” heading parent. Example (an alloy of 69.93% copper, 17.45% nickel, 10.29% aluminum, 1.50% cobalt, 0.83% iron): Copper alloy, base Cu 70,Ni 17,Al 10,Co 1.5,Fe 0.8 Binary alloys of 50-50% composition are indexed at the base heading for the metal with the earliest alphabetical element symbol. If ranges, rather than specific compositions, are supplied in the original document for all or some components, they are cited thus: Cu 68-73,Ni 16-18,Al 9-10,Co 1-2,Fe 0.7-1. Alloys of unknown percentage composition are entered only at nonbase headings, unless the base component is known. Example (An alloy of iron and thulium, base component unknown): Iron alloy, nonbase Fe,Tm The symbols are cited in alphabetical order, except that the base element is placed first if known; e.g., Al,Co,Fe,Ni or (for a cobalt base alloy) Co,Al,Fe,Ni. Alloys with trade names or code designations (other than standards) sometimes vary in reported composition; therefore, the numerical values are omitted from the entries. The base metal symbol is placed first and the others in alphabetical order; finally, the trade name or code designation is cited in parentheses. If only the base metal is known, the parenthetical expression alone is cited in the modification. Examples: Copper alloy, base Cu,Fe,Ni (Cunife I) Nickel alloy, base (Permalloy) Numerical values are included in entries for trade-named alloys of fixed composition and for those identified by the following U.S. standards: AA, AISI, AMS, ASTM, AWS, CDA, SAE, and UNS. The international standards of ISO and the standards of most other countries are also recognized for the purpose of CA indexing of alloys. Cermets are alloys containing nonmetals. They are indexed at metal alloy headings or at nonmetal headings with “alloy” in the modification depending on the composition. Example (a cermet containing tungsten carbide (WC) 94%, cobalt 6%): Tungsten carbide (WC) alloy, WC 94,Co 6 Alloys containing gases (0.1% or more) are indexed similarly. Example: Nickel alloy, base Ni 99,H 1 Steel is a heading parent for iron-carbon alloys so described and either containing a minimum of 97% iron or having no disclosed compositions. The steel composition or a designation (such as AISI 1017) which implies the composition is cited in the modification. Examples: Steel (AISI 1017) Steel Fe 98,Mn 1.5,Si 0.5,C 0.1 Isotopically labeled alloys are distinguished by the mass number on the element symbol. Example: Aluminum alloy, base Al 95,235U 5 215. Coordination compounds are molecules or ions in which a central atom (in polynuclear compounds, more than one) has atoms or groups of atoms, called ligands, attached to it to the extent of its coordination valency. The central atom may be of any element, but it is usually a metal atom. The metals comprise all elements except the following: Ar, As, At, B, Br, C, Cl, F, He, H, I, Kr, Ne, N, O, P, Rn, Se, Si, S, Te, Xe. (Prior to CA Volume 95 (see ¶ 101), antimony was also indexed as a nonmetal.) Compounds of nonmetals are generally not indexed as coordination compounds, but there are several exceptions, e.g., tetra- and hexavalent sulfur compounds (¶ 200), and borates containing ligands other than oxo and hydroxy. Hydride derivatives of antimony, bismuth, germanium, tin, and lead are not named as coordination compounds, but rather as covalent derivatives of the hydride heading parents, e.g., Stibine, Germane (¶¶ 181, 199). A ligand is any atom or group of atoms, charged or neutral, that is attached to the central atom of a coordination complex. The atoms of a ligand that are attached to the central atom are called coordinating atoms regardless of the type of bonding involved. A ligand with more than one coordinating site is described as multidentate; when more than one such site is engaged with a single central atom, it is a chelate ligand; when it is coordinated with two or more central atoms it is a bridging ligand. Neutral compounds with monoatomic ligands (except hydride) and mononuclear carbonyls and nitrosyls are given binary salt names. Common oligomeric salts are named in the monomeric form, e.g., Aluminum chloride (AlCl3), but studies of the dimers, etc., are indexed at the oligomeric names, e.g., Aluminum, di-µ-chlorotetrachlorodi-. Coordination compounds may be anionic, neutral, or cationic, in accordance with the oxidation state of the central atom and the number and nature of the ligands; when the latter are derived from the molecular skeletons of substitutive nomenclature, including nonmetal hydrides, by loss of hydrogen, they are considered negative in computing the total charge of the complexes containing them. This charge is expressed by a Ewens-Bassett number, e.g., (3+) or (2−), placed after the heading parent derived from the name of the central element; thus, Copper(1+), Borate(2−). Absence of a Ewens-Bassett number indicates that the complex expressed by the complete boldface heading is neutral. Ligands are cited in alphabetical order and their ligating atoms are identified by a modification of the Kappa system1. The periodic table symbol of the ligated atom is stated as an italic capital-letter locant preceeded by the greek letter kappa, e. g. κN, κO1, κS1. These letter locants are placed at the portion of the name corresponding to their attachment on the coordination center. Letter locants are not cited with (a) regular substituent prefixes, e.g., methoxy, phenyl, 2-pyridinyl; (b) other sigma-bonded ligands in which hetero atoms are either absent or uninvolved in the coordination; (c) monoatomic ligands, e.g., hydro, iodo; (d) ligands with unspecified bonding; (e) neutral and monoanionic organic ligands derived from cyclic or acyclic compounds containing only one hetero atom capable of coordination, e.g., triethyl phosphine, pyridine, N,Ndimethylmethanamine, N-methylmethanaminato, provided that the hetero atom is coordinated but no carbon atom is also bonded; (f) the following simple polyatomic inorganic ligands: amido, ammine, aqua, selenyl, telluryl, hydroxy, imido, mercapto, phosphino, and (except sometimes when present as bridges) azido, carbonyl, dinitrogen, dioxygen, nitrosyl, peroxy, and carbonothioyl. 1IUPAC, Nomenclature of Inorganic Chemistry, Recommendations 1990, Blackwell Scientific Publications, Oxford (England), 1990. ¶ 215 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 92 The preferred Chemical Substance and Formula Index entries for coordination compounds are made at the central element names (or the derived “-ate” names) as discussed above. Example: Cobalt(1+), (5,12-dimethyl-1,4,8,11-tetraazacyclotetradeca4,11-diene-κN1,κN4,κN8,κN11)-, (SP-4-1)-, [131154-44-4] Me N Co+ N H N Me H N Examples (letter locants are added to many of these names in particular coordination names; e.g., (acetato-κO,κO′)): −O 2C − (carboxylato) (this is an exception: not [carboxylato(2−)]) (acetato) − AcO− − CH 2 CO 2 [acetato(2−)] (diphenylphosphinyl) (diphenylphosphinito) [1,2-benzenediolato(2−)] Ph 2 ( O ) P − Ph 2 P( O ) O − OO−O 2 C( CH 2 ) 3 CO 2 − Cationic complexes are highest in order of precedence (¶ 106) among coordination compounds. (A positive element heading, e.g., Phosphorus(1+), is ranked just above the corresponding “-onium” heading, e.g., Phosphonium.) Neutral complexes are lower in the order of precedence, followed by anionic coordination compounds. For mixed polynuclear complexes, the preferred element (or derived “-ate”) heading is that appearing earliest in the following list: Rn, Xe, Kr, Ar, Ne, He, Fr, Cs, Rb, K, Na, Li, H, Ra, Ba, Sr, Ca, Mg, Be, (Lr to Ac), (Lu to La), Y, Sc, Hf, Zr, Ti, Ta, Nb, V, W, Mo, Cr, Re, Tc, Mn, Os, Ru, Fe, Ir, Rh, Co, Pt, Pd, Ni, Au, Ag, Cu, Hg, Cd, Zn, Tl, In, Ga, Al, B, Pb, Sn, Ge, Si, C, Bi, Sb, As, P, N, Po, Te, Se, S, O, At, I, Br, Cl, F. Many ligand names correspond to those of the substituent prefixes of general nomenclature. They include hydro, chloro (etc.), oxo, thioxo, hydroxy, mercapto, peroxy, diazenyl, and sulfo. Among ligand names which differ are the following: superoxido (O2−), amido (H2N−), imido (HN=), chloramido (ClHN−), nitrido (N≡), phosphido (P≡), arsenido (As≡). “Ato” ligand names are employed to express loss of hydrogen from inorganic “oxo” acids named as “-ic acids” and their chalcogen analogs. Those named as “-ous acids” correspondingly afford “-ito” ligands. Loss of one, two, etc., protons from polybasic acids is expressed by Ewens-Bassett numbers (loss of one hydrogen atom from most other classes of compounds is denoted simply by omission of a Ewens-Bassett number). Letter locants (see above) are sometimes employed. “Ato” and “ito” ligand names are always placed in enclosing marks. Examples: − O − PF (O ) − O − [pentanedioato(2−)] (2-hydroxyethyl acetato) (an ester is named in its uninverted form) (monomethyl sulfato) (derived from methyl hydrogen sulfate) (methyl glycinate) (derived from glycine methyl ester) A c O ( CH 2 ) 2 O − M e O − S( O ) 2 − O − H 2 N − CH 2 CO 2 M e [phosphorofluoridato(2−)] (perchlorato) [sulfato(2−)] [sulfito(2−)] (nitrito-κN) (not nitro) (nitrito-κO) (not nitrito) [hyponitrito(2−)] [phosphato(3−)] O 3 C lO − − − − OSO2O− O S (O )O − O2N− − O =N O − − O − N =N − O − O P(O − ) 3 Metal radical names (¶ 194) such as aluminio, aurio, and sodio, are used in the presence of higher compound classes or more preferred metals when the metal replaces a single hydrogen, but not to “place” a metal directly on another metal (see polynuclear complexes, below); e.g., Ethyl, 2-sodio- (a free-radical name); Potassium, (5-lithio-1-naphthalenyl)-. Because metal radicals carry no implication of valency, hydrogen and other attached atoms and groups must be expressed, e.g., dihydroaluminio for H2Al−. π-bonded ligands, and ligands attached to metal atoms by both π and σ bonds, are named by prefixing the Greek letter η (eta) or by using a combination of η and κ treatments. (Delocalized bonds are “fixed” for the purpose of naming the ligand so that lowest locants are given first to the point of attachment, then for unsaturation, etc.) Locants (if available) for atoms contributing to the ligand-metal bonding are cited ahead of “η” and the entire descriptor so formed is enclosed in parentheses; alternatively, if all the skeletal atoms of an unsubstituted conjugated acyclic or cyclic molecule or radical are involved, a superscript denoting the number of such atoms is cited immediately after “η” and the locants are omitted. Ligands with negative charges on adjacent hetero atoms are named instead as the neutral unsaturated compounds. σ-bonded ligands are named as regular radicals, e.g., 2,4-cyclopentadien-1-yl. (The name cyclopentadienyl is used without locants in the absence of further information.) Examples: The following cyanato radicals are employed: −OCN− −NCO− (cyanato-κN) (not isocyanato) − [(1,2,3-η)-2,4-cyclopentadien-1-yl] (cyanato-κO) (not cyanato) and similarly for thiocyanato, etc. Oxo acids which require synonym line formulas at their own heading parents are given more specific names when converted into ligands, e.g., [monothiosulfato(2−)], [trimetaborato(3−)]. Anionic carbon-attached ligands containing no anionic hetero atom attachments to the metal, and acyl ligands containing no anionic hetero atom attachments except for the acyl portion, are given names identical with those of normal substituent prefixes, e.g., ethyl, 2-pyridinyl, 1H-imidazol-2-yl, (phenylsulfonyl). Phosphino, phosphinyl, and (2-phenyldiazenyl) radicals are also used. Anionic ligands derived from heterocycles by loss of a proton only from a hetero atom in the ring, and containing no additional hetero atoms in the ring or substituents, are also named by substituent prefixes, e.g., 1-piperidinyl. All other anionic heterocyclic ligands are given “ato” names; they include porphines, phthalocyanines, corrins, other heterocycles containing rings of more than ten members, and heterocyclic ligands containing more than one hetero atom (including substituents). Unsubstituted phenoxy and methoxy through (dodecyloxy) radicals are used to express these ligands, but the chalcogen analogs and the substituted oxy radicals are named (1-chloromethanolato), (2propanolato) (not (1-methylethoxy)), (ethanethiolato), etc. Organic “-ic acids” and organophosphorus acids afford ligand names in which “-ic acid” or “-ous acid” is replaced by “-ato” or “-ito”, respectively. Ligands from esters are named in uninverted form. The “ato” suffix denotes loss of one proton in all cases unless a Ewens-Bassett number, e.g., “(2−),” is cited. − (η5-2,4-cyclopentadien-1-yl) CH 2 HC − — CH 2 (η3-2-propen-1-yl) [(1,2,3,3a-η)-azulene] M 93 −— O CH 2 O Me CH HC − — HC—CO 2Et Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 [(1,2,3-η)-4-oxo-2-cyclohexen-1-yl]NC − NC − CN − −CN ¶ 215 Fe 2+ − − CN • 2 ΝΗ 4 + • Cu 2+ (η 3-2-methylene-6-oxocyclohexyl) CN (The choice is based on the preferred parent radical; the locants “α,1,2-” cannot be used because “α-” does not relate to the parent radical.) E t O2 C Ferrate(4−), hexakis(cyano-κC)-, ammonium copper(2+) (1:2:1), (OC-6-11)- (Note that the ratio is expressed in the same order as the index name, i.e., first the heading, then the modification terms.) Cuprate(2−), [[1,1′-diethyl 2,2′[1,2-ethanediylbis[(imino-κN) methylidyne]]bis[propanedioato3 2 Κ+ κO ]](4-)]-, potassium (1:2) (Note that ring systems formed entirely by coordination are not recognized as such in index names.) O −− O +O 2 Ο CO 2 E t • Cu [(1,2,3-η)-4-ethoxy-1-methyl-4oxo-2-buten-1-yl] −N N − In polynuclear compounds (see below) a colon partitions the locants into sets to indicate bonding to different metal atoms. Examples: H 2C − M′— C H2C CH 2 M ′ — C− — M CH 2 CH 2 − C —M CH 2 [µ-[(η3:η3)-2,3-bis(methylene)-1,4butanediyl]] Anionic mononuclear complexes which contain simple anions as well as simple cations are named at the complex anion heading, as shown above. The cations are named in the modification, followed by the simple anions. Thus Borate(1−), tetrahydro-, europium(2+) bromide (1:1:1). When a complex or organic cation is present, this receives the preferred entry. Example: L i 4 [ Co ( N H 3 ) 6 ] 8 [ Fe ( CN ) 6 ] 7 Cobalt(3+), hexaammine-, (OC-6-11)-, lithium (OC-611)-hexakis(cyano-κC)ferrate(4−) (8:4:7) [µ-[(1,2-η:2,3-η)-1,2-propadiene]] When more than one complex anion is present, the choice is determined first by the preferred central element (see above); then by the highest numerical value, e.g., Antimonate(3−) is preferred over Antimonate(1−); finally, by the earliest index position of the entire entry. Example: − Br Br − Sb 3+ Br − Br − Br − Br − • − Br − Cationic molecules (¶ 184) are named in the unchanged (but uninverted) form when present as ligands, except that a Ewens-Bassett number denotes the charge when necessary; e.g., oxonium, [hydrazinium(1+)], [hydrazinium(2+)], (1-methyl-4-aza-1-azoniabicyclo[2.2.2]octane). When protons have been lost from hetero atoms of such ligands, “ato” names are used. Example: −N H Br Br Sb 5+ Br − • 4ΝΗ − 4 + Br − Br − Me 2 N + (C H 2 ) 2 O − [1-(2-hydroxyethyl)-1,1-dimethylhydraziniumato(2−)] Antimonate(3−), hexabromo-, (OC-6-11)-, ammonium (OC-611)-hexabromoantimonate(1−) (1:4:1) Complexes that contain ligands with uncoordinated acid functions, e.g., carboxylic acids or inorganic oxo acids, are named as though all acidic protons were dissociated from the uncoordinated groups; the cations and acid hydrogens are then cited in the modification. Examples: O P −O Enclosing marks are used with all “ato” ligand names and with ligands, like (cyano-κC), that have letter locants; “bis,” etc., (rather than “di,” etc.) are used to indicate two or more, e.g., bis(benzoato). When a Ewens-Bassett number is also present, the “ato” name is bracketed, e.g., [tetrahydroborato(1−)]. When such a ligand name includes a multiplicative radical (¶ 125), it is closed off and followed by the Ewens-Bassett number, which in this case may be (1−), and the total name bracketed. Example: OH −O − −OH − O O Ge 4+ O − O P • Na + • 2 H + O− O − Germanate(3−), hydroxybis[phosphato(3−)-κO, κO′]-, sodium hydrogen (1:1:2) SO3 C H = N (CH 2 ) 3 N = CH - [[2,2′-[1,3-propanediylbis(nitrilomethylidyne)]bis[phenolato]](1−)] Ligands from dioximes, trihydrazones, etc., are expressed by enclosing the name and then citing the Ewens-Bassett number (which may be (1−) in this case also) to indicate the number of protons lost; e.g., [(2,3-butanedione dioximato)(1−)]. Neutral ligands are enclosed by parentheses or brackets (as required), except for ammine, aqua, carbonyl, and nitrosyl, e.g., (dinitrogen), (phosphine), (benzene); they are multiplied by “bis,” “tris,” etc. Anionic mononuclear complexes are indexed at “-ate” headings derived from the name of the central element, e.g., Borate, Cuprate. The total charge of the complex anion is cited by a Ewens-Bassett number, and in the inverted part of the name the ligands are cited in alphabetical order. All cations are named in the modification in alphabetical order, except that hydrogen is placed last. Ratios are employed for all univalent and multivalent cations. For metals of variable valency, Ewens-Bassett numbers are cited after their names. Examples: F-F Al 3+ -F FFF• Η +• 2 Ν a + O3S 21a 21 20 N 19 18a 1 27 25a 26 30 N N -N 2+ 28a 28 29 Cu - 31 N 32 N 14 12 4a 5 6 N 7 7a •4 Νa+ N 13 SO3 - O3S Cuprate(4−), [29H,31H-phthalocyanine-2, 9,16,23-tetrasulfonato(6−)-κN29,κN30,κN31,κN32]-, sodium (1:4), (SP-4-1)- (not Copper, [29H,31H-phthalocyanine2,9,16,23-tetrasulfonato(2−)κN29,κN30,κN31,κN32]-, tetrasodium salt) Aluminate(3−), hexafluoro-, sodium hydrogen (1:2:1), (OC-6-11)(For the significance of the final term, see ¶ 203III.) Cationic mononuclear complexes are indexed at the central element names with a Ewens-Bassett number to indicate the total charge on the cation. The ligands are cited in the inverted part of the heading in alphabetical order, the associated anions (if any) in the modification; ion terms, e.g., “ion(1+),” are not cited. Ratios are used with all anions (both univalent and multivalent) and with mixtures of anions and cations, the first numeral relating to the heading cation, the others to the modification terms in sequence. The Formula Index headings ¶ 215 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 94 exclude the atoms expressed by modification terms. Example: MeN H HO Me 3 Me N − 2 Me C − O− N Co 3+ N Me • Me NC − − NC −CN − CN − CN Me 3+P 3+ HC Η C Η C CH Manganese, dicarbonyl[(1,2,3,4,5-η)1-methyl-2,4-cyclopentadien-1-yl] [phenyl(trimethylphosphonio) methyl]- Fe − CN N OH MeN H 2 O − CH Ph Mn + C≡ O C≡O Cobalt(1+), bis[[(2,3-butanedione di(oximato-κN)](1−)]bis(methanamine)-, (OC-6-11)-, (OC-6-11)-hexakis(cyano-κC)ferrate(3−) (3:1) Cationic complexes containing both complex mononuclear cations and simple cations are indexed at the names of the former; associated complex anions are also indexed as usual. Example: L i 2 H 2 [C o(N H 3 ) 6 ] 8 [ Fe ( CN) 6 ] 7 N + N • ClO 4− B3 −− O Boron(1+), (2,2′-bipyridine-κN1,κN1′) (oxydi-2,1-phenylene)-, (T-4)-, perchlorate (1:1) Cobalt(3+), hexaammine-, (OC-6-11)-, lithium hydrogen (OC-6-11)-hexakis(cyanoκC)ferrate(4−) (8:2:2:7) When more than one complex cation is present in a compound, the choice of preferred index entry is based on the nature of the central atom (see above for precedence list of elements), e.g., the heading parent Platinum(2+) is preferred over Palladium(3+). If the elements are alike, the complex with the higher positive charge is preferred. Example: H2 N Pt N H2 2+ Metallocenes (dicyclopentadienyl metal complexes in which all carbon atoms of the cyclopentadiene rings contribute to the metal-ligand bondings) are indexed at the parents Ferrocene, Nickelocene, Cobaltocene, Osmocene, Ruthenocene, etc. Example: Cl − Cl Fe 2+ − Ferrocene, 1,1′-dichloro- H2C H2C H2 N CH 2 CH 2 H2 C H2C H2 N Cl − Pt 4+ H2 N CH 2 CH 2 • 4 ClO 4 − N H2 N H2 Cl − N H2 Platinum(2+), bis(1,2-ethanediamine-κN1,κN2)-, (SP-4-1)-, dichlorobis(1,2-ethanediamineκN1,κN2)platinum(2+) perchlorate (1:1:4) Neutral mononuclear coordination complexes are indexed at the central element names without a Ewens-Bassett number. Example: F O − When additional ligands or ring systems more complex than cyclopentadiene are present, the compounds are indexed at the names of the central metals. All positions of each cyclopentadiene ring are considered equivalent, and substituents are assigned lowest locants without regard to attachment of the metal. In order of precedence, metallocenes are ranked with the neutral coordination complexes (¶ 106), Ferrocene, for example, being placed just below Iron as an index parent. Radical names, e.g., ferrocenyl, 1,1′-ferrocenediyl, can be formed. Example: CH 3 − 2+ Fe − C O HgCl | Mercury, [2-(acetyl-κO)ferrocenylκC]chloroSuffixes are not attached to metallocene heading parents, and conjunctive names are not derived from them; thus, Ferrocene, carboxy- (not Ferrocenecarboyxlic acid); Ferrocene, 1,1′-bis(carboxymethyl)- (not 1,1′-Ferrocenediacetic acid). Bridged derivatives are named by use of bivalent substituent prefixes. Example: − Fe − 2+ F O Cu 2 O + − Copper, bis[4-fluoro-2-(hydroxyκO)benzaldehydato-κO]- O Neutral complexes with internal charge compensation, e.g., with ligands which are inner salts, etc., are named according to structures provided in the original documents. Example: CH 3 N H 2C H 2C + Ferrocene, 1,1′:3,3′-bis(1,3propanediyl)- CH2 CH 2 Iron, trichloro(1-methyl-4-aza-1azoniabicyclo[2.2.2]octane-κN4)- The cationic analog of Ferrocene is named Ferrocenium. Example: − − CH 2 CH 2 N Fe 2+ Fe 3 + Fe3 + 1,1′′:1′,1′′′-Biferrocenium(2+) −C l Cl − Cl− − − H C− C O 2+ C O Cu SO 3 − Copper, diaqua[4-[1,3-di(oxo-κO) 3-phenylpropyl]benzenesulfonato(2−)]- H 2O O H 2 Polynuclear coordination complexes may have (a) direct linkages between the central metal atoms; (b) bridging ligands connecting them; (c) both kinds of linkages. A bridging ligand is designated by the Greek letter µ (mu); when it binds more than two central atoms, a subscript is cited with it, e.g., µ3. When the ligand name itself requires enclosing marks, an extra set is employed for the µ-ligand, otherwise none are used; e.g., µ-chloro, [µ-(acetato-κO:κO′)]. A µ-ligand is cited just ahead of the same ligand without the prefix, disregarding 95 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 216 in the ordering process any accompanying letter locants, e.g., [µ-(acetatoκO:κO′)] (acetato-κO). Colons within letter-locant sets indicate the distribution of bonds from a bridging ligand to individual metal atoms. Bridging ligands are not treated as multiplying radicals; i.e., the total of nonbridging ligands on all nuclear atoms is indicated directly. The number of nuclear atoms is indicated, after citation of all ligands, by “di,” “tri,” etc. Letter-locant sets are partitioned by colons. The cyclic structure of an oligomeric complex is indicated by “cyclo” as the first term in the modification. Direct linkages between like or unlike metals are always indicated, if known, by such terms as “(Fe-Fe)” or “(Co-Re),” whether or not bridging ligands are present. (In more complicated cases the total number of various bondings is expressed in terms such as “(3Co-Co)(3Co-Fe).”) For “cluster” compounds, in which three or more central atoms form a core, the geometrical descriptors triangulo, tetrahedro, or octahedro are assigned if the information is available. The term cluster is used for 13 or more direct metal linkages. The entry is made at the name (or derived “-ate” term) of the preferred metal, e.g., Cobalt, Cobalt(2+), Cobaltate(1−); other metals with their associated ligands are named as complex ligands of the preferred atom(s). These complex ligands are placed in a single alphabetical sequence with bridging and nonbridging ligands bonded to the preferred metal. (Metal radicals, e.g., cobaltio, mercurio, are not used in naming polynuclear complexes.) Examples: Et CO S −+ O C —Fe — Fe—C O − S CO OC Et OC + A polynuclear coordination complex of known formula but unknown structure is indexed at the heading parent for the most preferred central element (or its “-ate” term). The ligands are cited in the inverted part of the heading in alphabetical order, followed by the less preferred metals (or their “-ate” terms) in descending order of precedence. Examples: A lT iCl 2 E t 2 ( O H ) 2 Titanium, dichlorodiethyldihydroxy(aluminum)Aurate(2−), hexachloroargentateNiobate(8−), trioxododecakis[sulfato(2−)]hexaCopper(3+), pentahydroxytetrakis[2,2′,2′′-nitrilotris[ethanol]]tetra- [ A g A u Cl 6 ] 2 − [ N b 6 O 3 ( SO 4 ) 1 2 ] 8 − [ Cu 4 ( O H ) 5 [ N [ ( CH 2 ) 2 O H ] 3 ] 4 ] 3 + Iron, hexacarbonylbis[µ-(ethanethiolato)]di-, (Fe-Fe) CO o OC OC OC o CH = CHCO Mn CO CO Cr 216. Dyes of established structure are indexed at their systematic names by the regular rules of substitutive nomenclature. The Colour Index2 is employed as the chief reference source for the chemical constitution of trade-named dyes. A dye of unknown structure is indexed at the C.I. name if this is available, otherwise only at a trade name or other designation used in the original document. When the Colour Index shows an indefinite structure, the systematic name is still used if this can be done by omission of one or more locants or by use of alternative locants, e.g., “5(or 6)-chloro-.” Example: SO 3 H Chromium, tricarbonyl[µ-[(1,2,3,4,5η)-1-[1-oxo-3-(η6-phenyl)-2propen-1-yl]-2,4-cyclopentadien1-yl]](tricarbonylmanganese)2+ Me N =N • Na HO (MeH g) 4 S Mercury(2+), tetramethyl-µ4-thioxotetraCO − Cr CO CO CO CO CO OC OC OC CO Mn 0 Chromate(1−), pentacarbonyl(pentacarbonylmanganate)-, (Cr-Mn) (Note: The “-ate” ending is used in all central atoms names in anionic complexes) 2-Naphthalenesulfonic acid, 6-hydroxy5-[2-(methylphenyl)diazenyl]sodium salt (1:1) (cross-reference at C.I. Acid Orange 16) OC OC OC 0 0 Ir 0 Ir 0 CO CO CO CO CO OC Ir OC OC Ir CO Iridium, dodecacarbonyltetra-, tetrahedro H 2N H 2N Pd S − 2+ − S− Ni − S S Pd NH 2 NH2 • 2 Cl − Palladium(2+), tetrakis[µ-[2(amino-κN)ethanethiolato-κS:κS]] (nickel)di, chloride (1:2) Deliberate mixtures (¶ 221) of dyes with known structures are indexed at each component with a “mixt. with” modification. Reaction products are not considered to be deliberate mixtures. When an author supplies a structure for a trade-named dye which has been assigned a C.I. name but no constitution in the Colour Index, an entry will be found at the systematic name for the author’s structures, and a separate entry, in the Chemical Substance Index only, at the C.I. name. The cross-reference continues to be based on Colour Index information; i.e., it runs from the trade name to the C.I. name as usual. If a trade name (or common name) is not listed in the Colour Index, the author’s information (a C.I. number or name, or a structure) is used to make the index entry, cross-references and synonym. Cyanine dyes (methines) are indexed systematically. Because the location of the charge may be shown differently in different documents, the preferred ring system (¶ 138) is selected as the site of the quaternized center in every case and, if further criteria are needed, the structure named is chosen to conform to the principles of maximum number of substituents, lowest locants, and earliest index position. Example (name in original document: 3′-ethyl-3-methyl-8-phenoxythiacarbocyanine iodide): Ph O | C +N Me I− Polynuclear complexes with extended structures caused by bridging ligands are indexed at monomer headings, with a modification term such as “homopolymer.” Bridging ligands within the monomeric unit are named as usual, but those which bind the units to one another are not named by use of the “µ” prefix. Examples: Cl− 2+ S N Et CHCH S Cu Cl − Cl− • Cs+ x Cuprate(1−), trichloro-, cesium (1:1), homopolymer Benzothiazolium, 2-[3-(3-ethyl-2(3H)-benzothiazolylidene)-1phenoxy-1-propen-1-yl]-3-methyl-, iodide (1:1) O− Cu 2 + CH 2 O− O CH HC= O Copper, [5-[(3-formyl-4-hydroxyphenyl)methyl]-2-(hydroxy-κO)x benzaldehydato(2-)-κO]-, homopolymer 2Colour Index, Society of Dyers and Colourists, Bradford, Yorkshire; and American Society of Textile Chemists and Colorists, Research Triangle Park, N.C., 3rd ed., 5 vols., 1971; vol. 6 (supplement to vols. 1-4), 1975; vol. 7 (supplement to vols. 1-4 and 6); 1982; vol. 5 (3rd revision) and vol. 8 (supplement to vols. 1-4, 6, and 7), 1987. ¶ 216 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 96 Fluoresceins, phthaleins, and sulfonephthaleins have tautomeric structures in which a heterocyclic ring may be considered closed or opened, with generation of a carboxyl or sulfo group. Example (fluorescein): O O (a) Particle classes; e.g., Bosons, Fermions, Leptons, Hadrons, Baryons, Mesons, Hyperons, Nucleons, Tachyons, Quarks. These terms are employed as General Subject Index headings. (b) Particles with symbols but no reported mass; e.g., Σ-Hyperon, π-Meson, Muon, Alpha particle, Beta particle, Neutron, Proton, Neutrino, Deuteron, Tau particle. The index headings have the form Meson, π, in which the particle symbol appears in the heading after the name. (c) Particles with unique symbols and masses; e.g., Hyperon Λ(2100), Positive Muon, π+-Meson(140). The index entries are of the form Muon, +(106) and Meson, π+(140). µ (d) Particle resonances without reported masses; e.g., Meson resonance K+ π, Nucleon resonance ∆, Nucleon resonance N*. The index entry corresponds to the information available, e.g., Nucleon, resonance; Nucleon, resonance ∆. For multiple resonances, more than one Chemical Substance Index entry appears; e.g., Meson, K, resonance Kππ; Meson, π, resonance Kππ. Spiro[isobenzofuran-1(3H),9′[9H]xanthen]-3-one, 3′,6′-di hydroxyOH HO O ↑↓ CO 2H HO O O Benzoic acid, 2-(6-hydroxy-3oxo-3H-xanthen-9-yl)- (e) Particle resonances with reported masses. Examples of index entries: Nucleon resonance N * (2040) These compounds and their derivatives, including metal salts, are named in the closed forms unless a covalently bound derivative of the acid group, e.g., an ester or amide, is present. The preferred (closed) forms are indexed as shown by the following cross-references: Fluorescein. Phenolphthalein. Sulfonefluorescein. Phenolsulfonephthalein. See Spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one, 3′,6′-dihydroxySee 1(3H)-Isobenzofuranone, 3,3-bis(4-hydroxyphenyl)See Spiro[3H-2,1-benzoxathiole-3, 9′-[9H]xanthene]-3′,6′-diol, 1,1-dioxide See Phenol, 4,4′-(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis- Meson, K resonance K + K + (1280) Meson, K resonance KN (1780) (preferred entry) Nucleon resonance KN (1780) (additional entry) (f ) Particles composed of nuclei of elements of less than 98% natural abundance; e.g., lithium-6, boron-10, are indexed in the modification at the element headings. Specific particles from isotopes of hydrogen and helium-3 and -4 are indexed at Proton, Deuteron, Triton, Tau particle, and Alpha particle, respectively. The zero-charge nucleon is indexed at Neutron. Examples of index entries (Notation in the original document: 115Inm (7Li,3n)119 Te): Lithium, reactions isotope of mass 7, indium-115 bombardment by Indium, reactions isotope of mass 115, bombardment of, by lithium-7 Tellurium, properties isotope of mass 119, nuclear energy levels of, metastable, from lithium-7 bombardment of indium-115 Neutron from lithium-7 bombardment, of indium-115 In particle-particle and particle-nuclei interactions, all new particles and nuclei are indexed, otherwise, interactions of known particles and nuclei are indexed according to the author’s emphasis. (g) Particles of nuclei of elements of at least 98% natural abundance. Such particles are not named at the beginning of the modification at the element name. Examples of index entries (Notation in the original document: (12C,αp)): Carbon, reactions ions of carbon-12, copper-63 bombardment by Copper, reactions isotope of mass 63, bombardment of, by carbon-12 Proton from carbon-12 bombardment, of copper 63 Alpha particle from carbon-12 bombardment, of copper 63 (h) Antielements and antiparticles are indexed at the element and particle names with “Anti-” as a prefix; the symbol (the usual one with a vinculum added) is cited in the heading after a comma, and the isotope number of the antielement is given in the modification; e.g., Antihelium, He, isotope of mass 4; Antiproton, p. The antielectron is indexed at Positron, and the negative muon and positive pion antiparticles are named as the particles of opposite charge, e.g., Meson, π+; Muon, µ−(106). 63Cu- Azo dyes from pyrazolines and from acetoacetanilide derivatives are indexed as the keto rather than the enol forms. Cationic resonance-stabilized diamino derivatives of phenazine, phenoxazine, phenothiazine, xanthene, etc., are generally indexed as possessing the cation within the ring. Lakes are pigments which comprise insoluble salts of soluble dyes. They are indexed at the systematic names, e.g., as calcium or barium salts at the acid heading parent, if the constitution is known. The structure of a transition-metal lake is usually not precisely defined; when it is, a coordination name (¶ 215) is used; otherwise it is indexed at a C.I. name (if such a name has been assigned to the lake itself) or at trade names. New dyes, as reported in patent specifications, are indexed at systematic names, including coordination names (for metal complexes of precisely stated structure). Zinc chloride double salts cause an indexing problem, both because the same dye can be used in the zinc-containing and zinc-free forms, and because the toxicity of soluble zinc salts renders misindexing a serious matter. The presence of zinc is never assumed; it is excluded from cross-references at C.I. names and included in index entries for a specific trade-named dye only when it is listed in the Colour Index as a zinc salt, or when its presence is indicated by an original document. When a ratio is known, the appropriate entry is made at the cationic heading, e.g., Benzenediazonium. Otherwise it is indexed as a molecular addition compound (¶ 192) of the “-ium” chloride and Zinc chloride (ZnCl2) with an indefinite ratio. Sulfur dyes seldom have a known constitution. The preferred entry is a C.I. name, if available; otherwise the trade name is indexed, or, as a last resource, the starting material, e.g., Phenol, 4-amino-, sulfur dyes from. 217. Elementary particles and their atomic and molecular states are indexed as chemical substances. Elementary particle names follow a systematic scheme.3 In this scheme, a given letter (Roman or Greek, upper or lower case) is used in the context of a given set of quantum numbers. This scheme replaces the haphazard assignment of letters used previously. These particles may be subdivided as follows: 3“Review of Particle Properties” published by the Particle Data Group is recognized as an authority in this field. It appears in alternate years in Physics Letters B and Review of Modern Physics (for example, see Physics Letters B, 1990, 239, I.6-I.11). 97 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 219 (i) Atomic and molecular states of elementary particles. General studies are indexed at such headings as Mesonic atom, K-Mesonic atom, and Muonic molecule. Specific atomic and molecular states are indexed at the element name (“compounds” category) or particle name. Examples of index entries: 1. The original document describes the KBe mesonic atom: Meson, K mesonic atom with beryllium (KBe) 2. The original document describes the exotic combination of muonium with chlorine: Muon, µ leptonic mol. with chlorine (µ+e−Cl0) The atomic and molecular states of elementary particles are assigned the preferred entry at the particle name, with an additional entry for the atom or molecule. (j) (e+e − ). Muonium and positronium are used for the bound states (µ+e − ) and Meitnerium (Mt); and 110 - Darmstadtium (Ds). For isotopically labeled inorganic compounds, see ¶ 220. Elements of atomic number higher than 110, prior to 1982, were indexed at such headings as Element 114. They are now named by a combination of three syllables derived from the atomic number, the numerals 0-9 corresponding to the syllables nil, un, bi, tri, quad, pent, hex, sept, oct, and enn. The final “n” of enn is elided before nil, and the “i” of bi and tri before ium, which is the invariant suffix. Example: Ununquadium (formerly Element 114) The initial letters of the first three syllables of the names provide the symbols from which synonym line formulas are derived for binary compounds of these superheavy elements. Example: Ununquadium fluoride (UuqF4) (formerly Element 114 fluoride (1:4)) These index headings are not subdivided into categories as is done for elements with established names (i.e., 1 through 110). Elements reported or discussed without specific reference to atomic number are indexed at Elements in the General Subject Index. Class headings in the same index, e.g., Group IVA elements, Alkaline earth metals, Halogens, Helium-group gases, Platinum metals, Transition metals, are employed for general studies of varying specificity. Molecular forms of the elements are indicated in the modification, except that hydrogen and its isotopes, and nitrogen, oxygen, and the halogens are assumed to be diatomic (unless the term “atomic” is cited). Examples: Sulfur, mol. (S8); Oxygen; Hydrogen, atomic. Uninverted salt-type heading parents are used to index binary compounds, double salts, mixed salts, and certain other ionic and simple covalent compounds. The electropositive (cationic) constituents are named first in alphabetical order, followed by electronegative (anionic) constituents in alphabetical order. In the case of binary compounds between nonmetals, that constituent is placed first which appears earlier in the following sequence: Rn, Xe, Kr, Ar, Ne, He, B, Si, C, As, P, N, H, Te, Se, S, At, I, CN, SCN, Br, Cl, O, O22−, F, N31−, OCN. (Elements not listed here are treated as metals; prior to the Tenth Collective Index (1977-1981) antimony was included among the nonmetals.) For monoatomic anions, the ending “-ide” is cited. When a binary compound contains only nonmetals, the same sequence determines the order of the total name, e.g., Silicon carbide (SiC). A synonym line formula follows the name of each uninverted salt-type heading parent. (Prior to the Tenth Collective Index (1977-1981), line formulas did not appear with unambiguous names, e.g., Sodium chloride, Zinc sulfide.) Beginning with the Twelfth Collective Period (1987-1991), line formulas may be expressed with decimals or numerical ranges as well as integers. Example: Sodium tungsten oxide (Na0.37WO3) Hydrides of the metals antimony, bismuth, germanium, tin, and lead are indexed at hydride names such as Germane (¶ 199). Halides are indexed as derivatives at these headings, e.g., Stannane, tetrachloro- (not Tin chloride (SnCl4)); Plumbane, diiodo-. Hydrides, halides, etc., of most other elements are indexed at headings such as Sodium hydride (NaH); Thorium hydride iodide (ThHI3). The hydrides of nitrogen have trivial names: Ammonia, for NH3; Amidogen, for NH2; Hydrazine, for N2H4; and Hydrazoic acid, for HN3. Some derivatives of ammonia also have trivial names: Chloramine, for NH2Cl; Fluorimide, for NHF2; Hydroxylamine, for HONH2; Sulfamide, for SO2(NH2)2; Sulfimide, for SO2NH. The cyclic trimer of sulfimide is indexed at the heterocyclic name: 1,3,5,2,4,6-Trithiatriazine, 1,1,3,3,5,5-hexaoxide. Chalcogen hydride names include Water, for H2O; Hydrogen peroxide (H2O2); Hydrogen trioxide, for H2O3; Hydroxyl, for HO; Hydroperoxo, for HO2; Hydrotrioxo, for HO3; Selenyl, for HSe; and Hydrogen sulfide (H2S). Salts of hydric cations such as Ammonium, Phosphonium, Nitric acidium, are indexed at uninverted salt names with the “-ium” term cited first, or at “oxo” acid headings with “-ium salt” terms in the modification. Examples: Ammonium chloride ((NH4)Cl) Phosphonium cyanide ((PH4)CN) Oxonium chloride ((OH3)Cl) Perchloric acid, compounds ammonium salt (1:1) (named like a metal salt of the same acid, see below) Salts of Hydrazine and Hydroxylamine are named as molecular addition compounds (¶ 192), e.g., Hydrazine, sulfate (2:1). Binary oxides are indexed at headings such as Sodium oxide (Na2O), Iron oxide (with a synonym line formula, if known), Chlorine oxide (ClO2). Uninverted peroxide, superoxide, and ozonide headings are also employed, e.g., (k) Hypernuclei from hyperon interaction with atomic nuclei, and quark nuclei from quark binding in atomic nuclei are indexed in the Chemical Substance Index at the element name. Examples: Helium hypernucleus of helium-5 Helium quark nucleus q((2 _1 3) He) 1 /3+ 218. Enzymes are indexed by CA at the names recommended by the Nomenclature Committee of the International Union of Biochemistry (IUB)4 and Supplements as far as is compatible with CA nomenclature and indexing practices. Each specific enzyme is assigned a CAS Registry Number which is cited after the preferred index name in the Chemical Substance Index, where entries are to be found. Names for enzymes may comprise (a) a trivial substrate name combined with an action term, e.g., Lactate dehydrogenase, which is indexed at Dehydrogenase, lactate (this is E.C., at which designation a cross-reference can be found); (b) a substrate name and the suffix “-ase,” e.g., Adenosine triphosphatase, which is indexed at Phosphatase, adenosine tri-; (c) a name, similar to those in (b), but from which a heading parent expressing the enzyme action cannot be readily separated, e.g., Asparaginase, which is indexed at this name; and (d) other single terms which may describe the source, e.g., Papain, or the action, e.g., Lysozyme or Chymotrypsin; such enzymes (mainly proteinases) are indexed at these names. Qualifying phrases, which form part of the total enzyme name, appear in parentheses in the boldface heading after the main part of the name and express coenzyme specificity, secondary enzyme activity, secondary product formed, etc. Sometimes more than one type of information is expressed in this way. Examples: Dehydrogenase, malate (decarboxylating) Synthetase, acyl coenzyme A (guanosine diphosphate-forming) Dehydrogenase, glyceraldehyde phosphate (nicotinamide adenine dinucleotide phosphate) (phosphorylating) General studies of enzymes, and new enzymes, will be found at Enzymes in the General Subject Index. When complete primary structural information (amino acid sequence) is reported for an enzyme, an entry with as much source specificity as possible is made, e.g., Pepsin A (human pancreas), and a separate CAS registration linked to the structural information is prepared. 219. Inorganic compounds are indexed at names based on United States usage and the recommendations of the International Union of Pure and Applied Chemistry. For elements 104-110, CAS follows the recommendations of the ACS Committee on Nomenclature: 104 - Rutherfordium (Rf); 105 - Dubnium (Db); 106 - Seaborgium (Sg); 107 - Bohrium (Bh); 108 - Hassium (Hs); 109 - 4Enzyme Nomenclature, 1992. Academic Press, Orlando, Florida, 1992, 862 pp. Supplements 1-3, Eur. J. Biochem. 1994, 223, 1-5; 1995, 232, 1-6; 1996, 237, 1-5. ¶ 219 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Example: C • 1 /1 0 H N O 3 98 Sodium peroxide (Na2O2). The oxides CO, CO2, SO2, SO3, and SiO2 are indexed at Carbon monoxide, Carbon dioxide, Sulfur dioxide, Sulfur trioxide, and Silica, respectively. Mixed-metal oxides containing only the oxide (O2−) anion are indexed at oxide headings, with the metals cited in alphabetic order, e.g., Iron zinc oxide (Fe2ZnO4). Hydroxides of one or more metals are indexed at metal hydroxide headings, e.g., Chromium hydroxide (Cr(OH)3). Mixed-metal oxides, hydroxides, and oxide-hydroxides that also contain a Group IA and/or Group IIA metal are named at oxy-anion headings with cation terms in the modification, e.g., Stannate (Sn(OH)62−), potassium (1:2), (OC-6-11)-; Tantalate (Ta6(OH)O187−), potassium (1:7); Molybdate(2−), tetra-µ-oxotetraoxoferratedi-, sodium (1:2). Hydroxide-oxides that contain no Group IA or IIA metals are indexed at such headings as Manganese hydroxide oxide (Mn(OH)O). The index heading parents Chromic acid (H2CrO4), Chromic acid (H2Cr2O7), Manganic acid (H2MnO4) and Permanganic acid (HMnO4) are retained. Hydroperoxides are indexed at peroxide headings with synonym line formulas, e.g., Sodium peroxide (Na(HO2)), for Na(OOH). Mixed peroxide, hydroperoxide, ozonide, and superoxide headings are also employed. Sulfides, selenides, and tellurides are named like the oxides. The compounds CS2 and COS are indexed at Carbon disulfide and Carbon oxide sulfide (COS), respectively. Uninverted salt-type headings are used for halides, amides, arsenides, azides, borides, carbides, cyanides, hydrazides, hydroxylamides, imides, nitrides, phosphides, and silicides. Synonym line formulas are used to differentiate the hydrazides (H3N21−) and (H2N22−); for special cases such as iodide (I31−), chloride (HCl21−), and fluoride (HF21−); and for arsine, phosphine, and stibine which have lost one or two protons, e.g., Arsenide (HAs2). Otherwise it is understood the anions are monoatomic and have lost all protons, e.g., As3− , P3−, Si4−. Examples: Sodium chloride (NaCl), Potassium iodide (KI), Potassium iodide (K(I3)), Calcium niobium fluoride [formula unknown], Sodium phosphide (Na(H2P)), Cyanogen chloride ((CN)Cl). In these compounds, and the oxides, sulfides, etc., discussed earlier, all metals are considered to be cationic. Nonmetals are placed in cationic or anionic sequence to balance the charges. If this violates the electronegativity sequence described earlier, all metals are named as cations and all nonmetals as “-ide” anion terms. Examples: Aluminum gallium arsenide ((Al,Ga)As) Cadmium silicon phosphide (CdSiP2) (not Cadmium phosphide silicide) Thallium phosphide selenide (TIPSe) (not Thallium selenium phosphide) Mercury iodide phosphide (Hg3I4P2) Solid solutions are normally indexed as mixed salts (oxides, etc.). Decimal fractions, which can include ranges of composition, are used as subscripts in the accompanying formulas to specify stoichiometric relationships when applicable. As a result of nonstoichiometry, decimal fractions may not add to whole numbers. The omission of such numerical designations indicates incomplete information on the proportions in the original document. Examples: Aluminum gallium arsenide (Al0.5Ga0.5As) Cadmium mercury telluride ((Cd,Hg)Te) Copper platinum sulfide (Cu1.7-1.8Pt3-3.2S6) Iron manganese zinc oxide (Fe2.3Mn0.5Zn0.2O3.9) Solid solutions that involve classes of substances, or are otherwise incompletely defined as to elemental constituents, are identified in the index modification by a phrase such as “solid solns. with ...” Example: Iron oxide (Fe3O4) solid solns. with ferrites Salts of interhalogen anions are indexed as coordination compounds (¶ 215), e.g., Iodate(1−), dichloro-, sodium, for Na[ICl2]. Acetylides are indexed at names such as Sodium acetylide (Na(C2H)). The common name Calcium carbide (Ca(C2)) is the single exception. Metal derivatives of substituted Ethyne and of other alkynes are indexed by organometallic nomenclature (¶ 194). Examples: B rC ≡ C A g E tC ≡ C N a Nitric acid, compd. with graphite (1:10) The following metal-oxide radical names are sometimes used: americyl (O2Am− and O2Am=), chromyl (O2Cr=), neptunyl (O2Np− and O2Np=), permanganyl (O3Mn−), perrhenyl (O3Re−), pertechnetyl (O3Tc−), plutonyl (O2Pu− and O2Pu=), titanyl (O2Ti=), uranyl (O2U− and O2U=), vanadyl, (OV−, OV=, and OV≡), and zirconyl (OZr=). These names, and those for the thio, seleno, and telluro analogs, are used for the ions, e.g., Vanadyl ion(2+), and to complete the salt names at coordination anion headings (¶ 215). They are not used for their compounds with simple inorganic salts, nonmetal oxo acids, or organic acids. Examples: U O 2 Cl 2 K 2 U O 2 ( SO 4 ) 2 Uranium, dichlorodioxoUranate(2−), dioxobis[sulfato(2−)-κO]-, potassium (1:2) The following nonmetal oxide radicals and their chalcogen analogs are employed: nitrosyl (ON-), nitryl (O2N-), sulfinyl (OS=) (thionyl is limited to halides and halogenides), sulfonyl (O2S=) (sulfuryl is limited to halides and halogenides), thiotrithiazyl (N3S4-), diphosphoryl (O3P2 ),disulfonyl (O5S2-), chlorosyl (OCl-), chloryl (O2Cl-), perchloryl (O3Cl-) (and similarly for other halogen radicals). For other phosphorus and sulfur radicals see ¶¶ 197, 200, 276, and the Illustrative List of Substituent Prefixes (Section H, ¶ 294). Examples: Cl- S( O 2 ) - S( O 2 ) - Cl ( SO ) Br 2 NOH(S2O7) ( Se O 2 ) Cl 2 Disulfonyl chloride Thionyl bromide Nitrosyl (disulfate) ((NO)H(S2O7)) Selenonyl chloride Compounds of the nonmetal radicals with “organic” acids (i.e., those named as principal groups on molecular skeletons, such as carboxylic and sulfonic acids, ¶ 165) are indexed as anhydrides (¶ 179). For carbonyl compounds, e.g., Carbonic dihydrazide, Imidodicarbonic diamide, Urea, see ¶ 183. Metal carbonyls and nitrosyls are indexed at binary headings when they are either mononuclear or of unknown polynuclear structure, e.g., Chromium carbonyl (Cr(CO)6), (OC-6-11)-. Polynuclear carbonyls and nitrosyls of known structures are named as coordination complexes. (Simple metal nitrosyl dimers may be hyponitrites, e.g., Na2N2O2, Hyponitrous acid, sodium salt (1:2).) Polynuclear carbonyls and nitrosyls of known composition are indexed as coordination compounds (¶ 215). Helium-group compounds are indexed like the analogous metal compounds, except that salts with acids are named at their own headings. Examples: KrF2 XeO4 K2[XeF8] X e ( ClO 4 ) 2 Krypton fluoride (KrF2) Xenon oxide (XeO4) Xenonate(2−), octafluoro-, potassium (1:2) Xenon perchlorate (Xe(ClO4)2) (not Perchloric acid, xenon(2+) salt) Oligomeric inorganic compounds, except clusters, are reduced to their empirical formulas when the structures are unknown. When the actual structure of the oligomer is defined in the source document or known from references, an entry is made at the empirical formula. Clusters with unspecified oligomeric bonding are not reduced to their empirical formulas. Examples: Al2Cl6 Aluminum, di-µ-chlorotetrachlorodiBeryllium, hexa-µ-chlorotri-, triangulo Be3Cl6 Silver, (2-bromoethynyl)Sodium, 1-butyn-1-ylMetal-containing inorganic clusters receive standard nomenclature for inorganic compounds, e.g., Sodium fluoride (Na7F7), Lithium potassium chloride (Li6K4Cl10). Nonmetallic inorganic clusters receive oligomeric names when the monomeric form does not receive a line formula. All other nonmetallic inorganic clusters receive regular inorganic names with a line formula denoting the oligomeric formula. Graphite compounds are indexed as molecular addition compounds. Prior to CA Volume 95 (see ¶ 101), binary headings such as Graphitic acid, Graphite nitrate, etc., were employed. 99 Examples: (H F ) 3 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 219 Hydrofluoric acid, trimer Sulfur fluoride (S7F42) (SF 6 ) 7 Complex, mixed, and multiple salts are indexed at their own headings or (if complex cations or anions are present) as coordination compounds (¶ 215). Mixed salts of a single oxo acid are indexed at the acid heading. Examples: Cl− − Cl — Co — Cl− • 3 Cs+ • Cl− Cl − | | 2+ Cobaltate(2−), tetrachloro-, cesium chloride (1:3:1), (T-4)Uranium chloride oxide (UCl2O) Cobalt nitrate sulfate (Co5(NO3)2(SO4)4) Sulfuric acid, ammonium iron(2+) salt, hydrate (2:2:1:6) Sodium chloride sulfate (Na4Cl2(SO4)) Boron phosphate (B(PO4)) UOCl2 C o 5 (N O 3 ) 2 (SO 4 ) 4 H 2 O 3 S• 1/2Fe• N H 3 •3H 2 O 2N aC l• N a 2 SO 4 B2O3•P2O5 Cyclic inorganic substances composed of two or more elements and containing no metals of Groups 1-13 are named as ring systems. Se Se S S 1,2,4,5,3,6,7- Tetrathiatriselenepane S Se S now, acids of metals (including antimony) are generally indexed at metal oxide and hydroxide headings, e.g., Antimony hydroxide (Sb(OH)3); however, the metal acid names Chromic acid (H2CrO4), Chromic acid (H2Cr2O7), Manganic acid (H2MnO4), and Permanganic acid (HMnO4) are retained as index heading parents. Chalcogen and peroxy analogs of these metal and nonmetal acids are named by prefixing the “-ic” or “-ous” acid name by seleno-, thio-, telluro-, or peroxy-. The number of substituting atoms or groups is indicated in the synonym line formula in the heading. For Carbonic, Carbonothioic, and Carbonoperoxoic acids, see ¶ 183. Other peroxy acid names include Peroxychromic acid (H2CrO2(O2)2), etc. The two mononuclear Boric acid headings are differentiated by the synonym line formulas HBO2 and H3BO3. Cyclic metaborates of the general formula HnBnO2n, in which n is equal to or greater than 3, are also indexed at this heading. Thio, etc., acids are named at such headings as Thioboric acid (H3BS3). Isopoly acids can be considered to arise formally by condensation of a mononuclear acid, thus, 2H3BO3 → H4B2O5 + H2O. The names used in indexing isopoly acids are the same as those of the mononuclear precursors, e.g., Boric acid (H4B2O5). The synonym line formulas are usually empirical, but molecular formulas are shown for cyclic “meta” acids. Thus, Boric acid (H3B3O3). For the former Hypoboric acid ((HO)2BB(OH)2) and its derivatives, see ¶ 182. Examples of peroxy and chalcogen analogs of isopoly acids are Peroxydicarbonic acid (see ¶ 183), Thioboric acid (H2B2S4), Thiosilicic acid (H4Si3O4S3), Selenotellurodiarsenous acid (H4As2Se3Te2). The single name Telluric acid is used in association with the following synonym line formulas: H2TeO3, H2TeO4, H2Te2O5, H2Te2O7, H6TeO6, H8Te2O10. Selenious and Selenic acid analogs in which one hydroxyl has been replaced by a univalent group are indexed at acid headings with nondetachable prefixes, e.g., Fluoroselenious acid (HSeFO2), Amidoselenic acid (Se(NH2)(OH)O2). Replacement of both groups leads to a nonacid heading, e.g., Selenic diamide (Se(NH2)2O2), Amidoselenonyl fluoride ((SeO2)(NH2)F) (acid halides rank higher than amides (¶ 106)). An example of a polyselenic acid derivative is Imidodiselenic diamide (NH[Se(NH2)O2]2). Sulfur oxo acids are functional parent compounds. Analogs in which sulfur is directly attached to a molecular skeleton, e.g., Benzene, Hydrazine, or Germane, are named as sulfonic, sulfinic, and sulfenic acids (¶ 165). For thionic acids, see ¶ 200. For Hydroxylamine-O-sulfonic acid, see ¶ 193. (Selenium oxo acids are named similarly, except that selenium analogs of Sulfoxylic acid and Hydroxylamine-O-sulfonic acid and those thionic acids in which the sulfur has been totally replaced are not recognized in indexing.) The mononuclear sulfur acids are: (HO)2S ( H O ) 2 SO Sulfoxylic acid Sulfurous acid (the selenium analog is Selenious acid.) Sulfuric acid (the selenium analog is Selenic acid.) O Dioxathiirane S O ( H O ) 2 SO 2 Organic derivatives of these substances may also be named as rings when there is no coordinate bonding. O CH3 S O Dioxathiirane, 3,3-dihydro3-mercapto-3-methyl- SH Ammoniates are expressed in the modification at salt names, unless the ammonia is coordinated, in which cases “ammine” coordination names (¶ 215) are employed. Hydrates of simple metal salts are named by modification phrases and as coordination compounds if water is the only coordinating ligand. When other ligands are present, “aqua” coordination names (¶ 215) are used. Uncoordinated water is expressed as “hydrate” in the modification. Examples: [N i(O H 2 ) 6 ] 2+ .2C l − Analogs and derivatives of these acids are named by use of nondetachable prefixes such as amido, imido, chloro, azido, thio, seleno, and peroxy, with replacement of the acid class name by the preferred suffix or class term if all hydroxyl groups have been removed. Compounds containing only sulfur (or selenium) and halogen are indexed at binary names, e.g., Sulfur chloride (SCl2). Monohydrazides are indexed at hydrazine headings, e.g., Hydrazinesulfonyl chloride for H2NNHSO2Cl. Some trivial names are employed. For Sulfur diimide, see ¶ 200. Examples: H2N(HO)S H 2 N SCl H O ( N C) SO Cl( N C) SO Amidosulfoxylic acid Amidosulfenyl chloride Cyanosulfurous acid Thionyl chloride cyanide Thiosulfurous acid (H2S2O2) Amidoimidosulfurous chloride Azidosulfuric acid Chlorosulfuric acid Sulfamic acid Sulfuryl chloride Nitrososulfonyl fluoride Imidosulfamic acid Sulfamide, N,N-difluoroChloroimidosulfuric acid Thiosulfuryl chloride ((S2O)Cl2) Imidosulfamide Nickel(2+), hexaaqua-, chloride (1:2), (OC-6-11)Nickel chloride (NiCl2), hydrate (1:6) Phosphoric acid, calcium salt, hydrate (4:6:3) (HO) 2 S(S) (or HO(HS)S(O)) Cl( H 2 N ) S=N H H O ( N 3 ) SO 2 Cl( H O ) SO 2 H O ( H 2 N ) SO 2 Cl 2 SO 2 F( O N ) SO 2 H O ( H 2 N ) S( O ) =N H F 2 N ( H 2 N ) SO 2 Cl( H O ) S( O ) =N H Cl 2 S( O ) S ( H 2 N ) 2 S( O ) =N H N iC l 2 .6H 2 O C a 3 (PO 4 ) 2 .3/2H 2 O Binary and pseudobinary inorganic acids are restricted to Hydrofluoric, Hydrochloric, Hydrobromic, Hydriodic, Hydrocyanic, Hydrazoic (HN3), Fulminic (HONC), Cyanic, and Thiocyanic acid, together with Hydrogen triiodide (HI3) and oligomers such as Hydrochloric acid, dimer. (For isocyanic and isothiocyanic acids, see ¶ 183.) Inorganic oxo acids. Protonic acids of anions containing only oxo or hydroxy ligands are given names terminating in “-ic acid” or “-ous acid.” Acids ending in “-ous acid” are limited to the lower valent compounds of the elements F, Cl, Br, I, S, Se, N, P, and As. The prefix “per-” is used to designate one oxo acid of manganese (see below), peroxy acids of boron, and oxo acids of the halogens in the 7+ oxidation state. Inorganic oxo “-ic” and “-ous” acid names are in general limited to hydroxy and oxo-hydroxy compounds of the nonmetals As, At, B, Br, Cl, F, I, N, P, S, Se, Si, and Te, in any oxidation state. Prior to the Tenth Collective Index (1977-1981), metal acid headings were employed; ¶ 219 H O O (H O )SO 2 H O (H S S )SO 2 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Peroxymonosulfuric acid Thioperoxymonosulfuric acid ((HO)(HSS)SO2) Nitrogen oxo acids are indexed at the following headings: HONO HONO2 HON=NOH HON=N(O)OH 100 Nitrous acid Nitric acid Hyponitrous acid Hyponitric acid Polynuclear sulfur and selenium acids have such names as Disulfuric acid (for (HO)S(O2)O(O2)S(OH)), Diselenious acid (for (HO)Se(O)O(O)Se(OH), Trisulfuric acid, etc. Analogs are named by use of nondetachable prefixes and replacement of the acid term (if all hydroxyl groups are absent). Examples: (N 3 )S O 2 O SO 3 H H O (SO 2 N H ) 2 SO 3 H H 2 N S O 2 N H SO 3 H H O 3 SO O S O 3 H Azidodisulfuric acid Diimidotrisulfuric acid Amidoimidodisulfuric acid Peroxydisulfuric acid ([(HO)S(O)2]2(O)2) Trisulfuryl chloride Disulfamide 1,1-Hydrazinedisulfonyl dichloride Halide and halogenoid derivatives are indexed at nitryl and nitrosyl names, e.g., Nitrosyl chloride ((NO)Cl). The amides of nitric and nitrous acid are Nitramide and Nitrosamide, respectively; organic derivatives are named as N-nitro and N-nitroso amines. Halogen oxo acids include: HOCl Hypochlorous acid HOBrO HOClO2 HOIO2 (HO)2IO2 HOClO3 HOIO3 (HO)5IO Bromous acid Chloric acid Iodic acid (HIO3) Iodic acid (H2IO4) Perchloric acid Periodic acid (HIO4) Periodic acid (H5 IO6) C lSO 2 O SO 2 O S O 2 Cl H2NSO2OSO2NH2 (C lS O 2 ) 2 N N H 2 Phosphorus and arsenic acids. For mononuclear phosphorus and arsenic acids, both nonsubstitutive, e.g., Phosphoric acid, Arsenous acid, and substitutive, e.g., Phosphonic acid, see ¶ 197. There are no official rules for naming polynuclear phosphorus and arsenic acids; they are indexed by CA at names traditionally used in the literature. Pyrophosphoric acid and its analogs and derivatives are indexed at Diphosphoric acid names, and similarly for Pyrophosphorous acid. Specific esters of Metaphosphoric acid (H3P3O9) are indexed at the heterocyclic parent 1,3,5,2,4,6-Trioxatriphosphorinane (¶ 197), and other meta acids are treated similarly. Mixed polynuclear phosphoric-phosphorous acids are indexed at headings which include Stock numbers (parenthetical Roman numerals) to indicate the sequence of trivalent and pentavalent phosphorus atoms. When all hydroxyl groups have been replaced, the acid term gives way to acid halide, amide, etc., suffixes. Amides of polyphosphorous acids are indexed by replacing the word “acid” by “amide” preceded by a multiplicative prefix; amides of polyphosphoric acids have names in which “ic acid” is simply replaced by “-amide,” e.g., Diphosphorous tetraamide, for [(H2N)2P]2O, and Peroxydiphosphoramide, for [(H2N)2P(O)]2O2. P,P′, etc., locants are used to designate the position of replacement amido and imino, bridging imido, etc., groups. Arsenic analogs are named analogously to the phosphorus examples below, except that “Hypo-” and “Isohypo-” names and headings in which mixed valencies are denoted by “III” and “V” terms are not employed. Examples: (HO)2P(O)OP(O)(OH)2 (HO)2P(O)OP(O)(OH)OP(O)(OH)2 (HO)2P(O)P(O)(OH)2 (HO)HP(O)P(O)(OH)2 (HO)2POP(OH)2 (HO)2POP(O)(OH)2 (HO)2POP(O)(OH)OP(OH)OP(O)(OH)2 (HO)2P(O)NHP(O)(OH)2 [(HO)2P(O)OP(O)(OH)]2NH Cl2P(O)OP(O)(OH)Cl H2N(HO)P(O)OP(O)(OH)2 (HO)2POP(O)(OH)NH2 HO(HS)P(O)SP(O)(OH)SH Mixed halides are indexed at such names as Chloryl fluoride ((ClO2)F). Silicon oxo acids in CA indexing are named as Silicic acid with one of the following synonym line formulas: H2SiO3, H4SiO4, H2Si2O5, H6Si2O7. The same index heading is employed for cyclic acids of the general formulas H2nSinO3n and H2nSi2nO5n in which n is equal to or greater than 3. The compound (HO)3SiSi(OH)3 is named Disilanehexol. (See also ¶ 199.) Anhydrides of inorganic oxo acids with carboxylic, sulfonic, etc., acids are indexed at the organic acid heading (¶ 179); mixed inorganic anhydrides which contain neither free nor esterified hydroxyl groups are given uninverted salt names. Examples: ClONO2 B(OPO2)3 Chlorine nitrate (Cl(NO3)) Boron metaphosphate (B(PO3)3) When free (or esterified) hydroxyl groups are present, the index entry is made at the preferred acid heading with an “anhydride with” phrase is the index modification. Examples: EtOSO2OClO3 Diphosphoric acid Triphosphoric acid Hypophosphoric acid Isohypophosphoric acid Diphosphorous acid Diphosphoric(III,V) acid Tetraphosphoric(III,V,III,V) acid Imidodiphosphoric acid P′-Imidotetraphosphoric acid Trichlorodiphosphoric acid Amidodiphosphoric acid P′-Amidodiphosphoric(III,V) acid Thiodiphophoric acid ([(HO)(HS)P(O)]2S) Thioperoxydiphosphoric acid ([(HO)2P(S)]2S2) P-Amido-P′-thiodiphosphoric (III,V) acid Amidodiphosphoryl chloride Diphosphoryl chloride fluoride (Cl2P(O)OP(O)ClF) Nitridotriphosphoric acid P′-Iminodiimidotriphosphoramide H3PO4 • NH3 • Mg HOSO2OSi(OH)2OSO2OH Perchloric acid, anhydride with ethyl hydrogen sulfate Sulfuric acid, anhydride with silicic acid (H4SiO4) (2:1) Mixed anhydrides of inorganic peroxy and thio (etc.) acids are indexed similarly, with use of “anhydrosulfide with” terms when appropriate, but anhydrides with a peroxy, dithio, etc., linkage are indexed at Peroxide, Disulfide, etc. Example: HO3SSSP(O)(OH)2 Disulfide, phosphono sulfo Metal (and helium-group element) salts of inorganic oxo acids and their analogs are indexed at the oxo heading if only one anion is present (otherwise the salt is indexed at its own heading, e.g., Potassium phosphate sulfate (K2H3(PO4)(SO4)). A Ewens-Bassett number is cited with a metal of variable valence, and the stoichiometry of the salt is indicated by “mono,” multiplicative prefixes, or ratios, when necessary. Examples: 3 HClO3 • Al 3 HNO3 • Ag H2SO4 • Ca HOSO2OSO2OH • Na 2 H2NSO2OH • Sn HN(SO2F)2 • Ag Chloric acid, aluminum salt (3:1) Nitric acid, silver(1+) salt (3:1) Sulfuric acid, calcium salt (1:1) Disulfuric acid, sodium salt (1:1) Sulfamic acid, tin(2+) salt (2:1) Imidodisulfuryl fluoride, silver(1+) salt (1:1) Phosphoric acid, ammonium magnesium salt (1:1:1) Xenon perchlorate (Xe(ClO4)2) (HO)2P(S)SSP(S)(OH)2 H2N(HO)POP(S)(OH)2 Cl(H2N)P(O)OP(O)Cl2 Cl2P(O)OP(O)(Cl)F [(HO)2P(O)]3N [(H2N)2P(O)NH]2P(=NH)NH2 For further examples, see ¶ 197. 2 HClO4 • Xe 101 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 220 Alums, chrome alums, etc., are indexed (a) at oxo acid names, e.g., Sulfuric acid, compounds, aluminum potassium salt, hydrate (2:1:1:12), (b) at “ium” headings, e.g., Methanaminium, N,N,N-trimethyl-, aluminum sulfate (1:1:2) or (c) (if they contain conjugate acids of nitrogen bases) at names of acids and bases, e.g., Sulfuric acid, aluminum salt, compd. with guanidine (1:1:1). Anions are indexed at names usually identical with those employed in binary cation-anion headings (see above), e.g., Hydride, for H1−; Carbide, for 4−; Carbide (C 2−); Hydrazide (H N 1−). Anions from inorganic oxo acids C 2 32 are indexed at “ate” and “ite” headings with the retained hydrogen atoms or derivatives expressed in the modification; an ion term is expressed for esters and salts. Oxo anions of metals have synonym line formulas; other polyatomic anions are assigned coordination anion names. Examples: H 2 PO 4 − EtSO 4 − AlO 2 − NO 3 2 − jectival terms all end in “-an,” and are derived from the English or Latin names of the elements, e.g., aluminian, beryllian, hydrogenian, aurian (from gold), sodian, zincian. The forms “-oan” and “-ian” are used for the lower and higher oxidation states of arsenic, copper (cuproan and cuprian), iron (ferroan and ferrian), lead (plumboan and plumbian), manganese, mercury, and uranium. Example: (Ba,Li)Si2O5 Sanbornite, lithian Intermetallic compounds are indexed like molecular addition compounds (¶ 192). Only one index entry is made at the name of metal that is alphabetically preferred. Example: Sb2Fe Phosphate, hydrogen (1:2) Sulfuric acid, monoethyl ester, ion(1−) Aluminate (AlO21−) Nitrate(2−), trioxo- Antimony, compd. with iron (2:1) Anions of elements without “-ide” names are indexed at the element names, with “ion” modification terms followed by a symbol to show the charge and composition, e.g., ion (Re1−), ion (Hg22−), ion (S81−). Cations. The cation of hydrogen in the gas phase is indexed at Proton (¶ 217). Examples of other cation names are Sulfonium, for SH31+; Chloronium, for ClH21+; Ammonium, for NH41+; Ammoniumyl, for NH31+; Hydrazinium(1+), for N2H51+; Diphosphinium(2+), for P2H62+; Thiosulfuric acidium(1+) (H3S2O31+); Plutonyl ion(1+), for PuO21+; Nitryl ion, for NO21+; Magnesium(1+), diiodo-, for MgI21+; Helium(1+), hydro-, for HeH1+. Cations of elements are indexed at element headings with the ion specified in the modification, e.g., Carbon, ion (C21+). Minerals are indexed at traditional and new mineral names as correlated by the Commission on New Minerals and Mineral Names of the International Mineralogical Association and reported in The American Mineralogist. Other references used to standardize the spelling and transliteration of mineral and rock names, as well as to standardize mineral formulas in the CA indexes are: (a) American Geological Institute, Glossary of Geology, Washington, D.C., 1972, 857 pp. (b) E. S. Dana, A Textbook of Mineralogy, 4th ed., revised and enlarged by W. E. Ford, John Wiley and Sons, New York, 1958, 851 pp. (c) J. D. Dana and E. S. Dana, System of Mineralogy, 7th ed., entirely rewritten and enlarged by C. Palache, H. Berman, and C. Frondel, John Wiley and Sons, New York, Vol. I, 1944; Vol. II, 1951; Vol. III, 1962. (d) R. W. Fairbridge, The Encyclopedia of Geochemistry and Environmental Sciences (Volume IVA of The Encyclopedia of Earth Sciences series), Van Nostrand Reinhold Co., New York, 1972, 1321 pp. (e) M. Fleischer, Glossary of Mineral Species, Mineralogical Record, Tucson, Arizona, 1980, 192 pp. (f) M. H. Hey, An Index of Mineral Species and Varieties, 2nd rev. ed., Trustees of the British Museum (Natural History), London, 1955, 728 pp. Appendixes, 1963, 135 pp; 1974, 168 pp. (g) C. Hintze, Handbuch der Mineralogie, Supplement 2, Neue Mineralien und Neue Mineralnamen, Walter de Gruyter, Berlin, 1960, 958 pp. (h) C. M. Rice, Dictionary of Geological Terms, Edwards Brothers, Ann Arbor, Mich., 1961, 465 pp. (i) H. Strunz, Mineralogische Tabellen, 4th rev. ed., Akademische Verlagsgesellschaft Geest und Portig K.-G., Leipzig, 1966, 560 pp. (j) P. W. Thrush, A Dictionary of Mining, Mineral, and Related Terms, U.S. Department of the Interior, 1968, 1269 pp. Minerals of definite composition have a synonym line formula cited after the name, e.g., Chromatite (Ca(CrO4)). When no mineral formula is given in the original document, the assumed formula is that given in reference (e), above. New minerals are indexed at names and formulas supplied in original documents and collected in each issue of the General Subject Index at New minerals. When one or more elements have replaced the whole or part of the original element in a mineral, and no new mineral name has been coined, the replacing element is named in the modification at the original heading. Examples: BaSi 2 O 5 Li 2 Si 2 O 5 LiNaSi 2 O 5 Zn 2 SiO 4 ZnMgSiO 4 220. Isotopes. The isotopes of hydrogen of atomic masses two and three are indexed at Deuterium and Tritium, respectively. Isotopes of other elements with a natural abundance less than 98% are indexed at the usual element names with a phrase in the modification: “isotope of mass...” When the isotope is metastable, this word appears in the descriptive part of the modification, e.g., “formation of metastable.” Anions of nonmetals are named in the index headings, metal anions and all cations in the modification. Examples: Chloride (38Cl1−) Hydride-d (not Deuteride) Tin, isotope of mass 120 (120Sn1−) Chlorine, isotope of mass 37 (37Cl1+) Molecular forms of isotopic elements are named in the index heading or indexed with “mol.” or “ion” terms in the modification; “mol. with” phrases are employed for mixed hydrogen isotopes. Examples: Iodide (131I31−) Nitrogen mol. (N15N) (a labeled atom is cited after an unlabeled atom of the same element) Helium mol. (3He2) Deuterium ion (D21+) Tritium mol. with hydrogen (HT) Isotopically labeled organic compounds are indexed by the Boughton system by placing the symbol for the isotope (with a subscript numeral to indicate the number of isotopic atoms) after the name or after the relevant portion of the name. When the isotopic labeling is part of the heading parent, locants are cited unless the labeled atom is one of the following: (a) one or more labeled atoms attached to-or replacing-the central atom of a mononuclear molecular skeleton; (b) one or more labeled atoms included in a single functional suffix; (c) a single labeled atom included in a homogeneous parent with two skeletal atoms and no functional suffix; (d) a single labeled atom included in a homogeneous monocyclic ring with no functional or conjunctive suffix; (e) a labeled heteroatom included in a ring that has only one heteroatom of that kind; or (f) a labeled atom whose locant duplicates the element symbol. The locants (except Greek letters) and symbols are in italics, and hyphens are used to separate them from one another and from the remainder of the names. (In the following examples “d” has been used, but the tritium-labeled compounds are named quite analogously by citation of “t.” When both “d” and “t” are cited, they are separated by a hyphen, e.g., Ethane-1-d-2-t.) In labeled heading parents with single-word names and no hydrogen-containing principal group, the d is placed after the parent. Examples: MeD CD4 F3CCH2D D Cl CD 3 Methane-d Methane-d4 Ethane-d, 2,2,2-trifluoro(not Ethane-2-d, 1,1,1-trifluoro-) Benzene-d, 2-chloro-6-(methyld 3)- (not Benzene-2-d, 1-chloro-3-(methyl-d3)-) Phosphine-d2, methylUrea-N,N,N′,N′-d4 Sanbornite (Ba(Si2O5)) Sanbornite lithium (Li2(Si2O5)) Sanbornite lithium sodium (LiNa(Si2O5)) Willemite (Zn2(SiO4)) Willemite magnesium (ZnMg(SiO4)) MePD2 (D2N)2CO When partial replacement has occurred but stoichiometric information is lacking, or when unusual elements are present, adjectival terms for these elements are cited in the modification in the Chemical Substance Index. The ad- ¶ 220 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 102 Deuterated alcohols, amines, or imines are indexed similarly. The “d” symbol is placed after the appropriate part(s) of the name. Examples: DOND2 D3CCD2OD (D3C)2NH H3SiND2 DNHOD D(CH2)2NH2 MeOD MeSO3CH2D Hydroxyl-d-amine-d2 Ethan-2,2,3,3,3-ol-d Methan-d3-amine, N-(methyl-d3)Silanamine-d2 Hydroxyl-d-amine-d Ethan-2-d-amine Methanol-d Methan-d-ol, 1-methanesulfonate (isotopically labeled “Class I” alcohols (¶ 185) belong to “Class II”) CD2 SH When locants are expressed in a heading parent or parent radical for unsaturation, hetero atoms, indicated hydrogen, spiro or ring-assembly junctions, bridges (in fused ring systems), suffixes, or points of attachment (in radicals), locants are cited for the labeled positions, whether or not their use would otherwise be necessary. Example: (D 3 C) 2 CO 2-Propanone-1,1,1,3,3,3-d6 Exceptions are “d” and “t” terms placed after the word “acid” and after the suffixes of amines, imines, alcohols, etc. (see above), for which locants are seldom employed. The examples above have dealt with organic compounds labeled with deuterium (tritium-labeling is handled similarly). Isotopes of elements other than hydrogen in organic compounds are expressed by the appropriate symbols. Nomenclature is similar, except that the instances in which the isotopic symbol appears within the name are restricted to (a) names comprising more than one word, (b) acids and acid derivatives with “carboxylic”, “sulfonic,” etc., names, and (c) conjunctive names. Examples (labeled atoms are indicated by asterisks): MeC(O)OH ∗ Ph C( O ) O M e ∗ ∗ Ph CH 2 CO 2 H ∗ M e CO F ∗ ∗ O =C=O ∗∗ H 3 G e CN ∗ O ∗ CO 2 H ** D Benzene-4-d-methane-α,α-d2thiol Acetic-17O2 acid Benzoic-18O acid 16O-methyl ester Benzeneacetic-carboxy,α-14C2 acid Acetyl-17O fluoride Carbon dioxide-18O2 Germane-74Ge-carbonitrile-15N D D D OMe OH D Phen-2,3,4,5-d4-ol, 6-methoxy(not Phen-3,4,5,6-d4-ol, 2-methoxy-) MeCH(ND2)CO2D D N N Alanine-N,N,1-d3 1H-Imidazole-1-d-2-carboxylic acid-d C O2D When a heading parent contains locants the labeling of each part is expressed separately and locants for the labeling are cited. Example: DOCD2CD2OD Cyclohexanecarboxylic-14C acid, 2-(oxo-17O)- 1,2-Ethane-1,1,2,2-d4-diol-1,2-d2 ∗ Me ∗ SO 3 ( CH 2 ) 2 Cl The “d” symbol is placed after the appropriate word in multiword headings for classes not yet discussed, e.g., Acetic-2,2,2-d3 acid-d; Acetyl-2,2,2-d3 chloride. In most other cases the “d” is cited after the complete heading parent, and conventional locants or italicized words are often necessary to denote the labeled position. Examples: DCH2CDO D(CH2)2CONHD C HD 2 D 2C H CDO Benzene-2-14C-sulfonic-35S acid 2-chloroethyl ester (labeled “Class I” acids (¶ 185) belong to “Class II”) Acetaldehyde-1,2-d2 Propanamide-N,3-d2 Benzaldehyde-formyl-d, 2,4-di(methyl-d2)- (not “bis(methyld2)”; the labeled and unlabeled compound names are kept as similar as possible) In general, for all other compounds isotopic labeling of a heading parent is expressed after the name, although, as in the first example below, a combination of these policies with those for “d” (or “t”) is sometimes necessary. Symbols for different isotopic elements which fall together are cited in alphabetical order and separated by hyphens. Labeling of radicals is expressed after the individual simple radical names. Examples: • D CH 2 CH 2 O H ** M e CO N H 2 * M e CO N D CH 2 CH D M e Ethan-2-d-ol-1-14C Acetamide-1-13C-15N Acetamide-N-d-15N, N-(propyl2-d)Benzoic acid, 4-(2-propen-1-yl-314C-oxy)- Enclosing marks are used with a labeled radical if it is preceded by a locant which expresses its attachment to a heading parent or parent radical, but not if such a locant belongs to the radical itself. Examples: D3 C CH 2 CD 3 Benzene, 1-(ethyl-2,2,2-d3)-4(methyl-d3)- ∗ H2 C = CH CH 2 O C O2 H D N N H C O2 H Carbamic acid, N-(2-piperidinyl-1-d)- Addition of deuterium, alone or with hydrogen, to a ring system is indicated by hydro “substituents” and the “d” symbol. Where there is a choice, deuterium is expressed in the heading parent. Example: Me OH D Apart from isotopes of “hydro” (see above), a multiplicity of substituents that are identical except for labeling are named separately. Multiplicative nomenclature is not employed with unsymmetrically labeled parents; instead, that heading parent is chosen which contains (a) the maximum number of isotopic atoms, (b) the alphabetically earliest isotope symbol. Examples: ∗ ( H 3 C) 2 SiM e 2 Silane, dimethyldi(methyl-13C)Methylene, chloro-35Cl-chloro-37Cl2-Propanamine-2-14C, N-(1methylethyl-1-d)- (not 2Propan-2-d-amine, N-(1methylethyl-1-14C)-) 1-Naphthalen-2,4-d2-ol, 1,2,3,4tetrahydro-4-d-1-methylD D ∗ Cl 2 C : ∗ M e 2 CH N H CD M e 2 Labeled protonated species (¶ 184) are expressed in index modifications by terms such as “conjugate acid-d (1:1)” and “monoprotonated-d”. 103 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 221 For derivatives named in modifications, labeling is expressed by such terms as “oxime-15N,” “calcium-44Ca salt,” “hydrate-d2 (1:2).” Ammonium-d4 salts are treated like the analogous metal salts. A name containing isotopic symbols is always employed for a labeled compound, regardless of how little of the labeled species is present so long as its nature is known. When the number of labeled atoms is unknown, the heading for the unlabeled compound is indexed and the modification contains a phrase such as “labeled with deuterium” or “labeled with chlorine-37.” Examples: Acetamide, labeled with carbon-14 1-Propene, 1,1,2,2,3,3,3-hexachloro-, labeled with chlorine-36 When only the positions of the isotopic atoms are unknown, the labeling is indicated, if possible, in the appropriate part of the name without citation of locants. Otherwise a “labeled with...” modification is used. Examples: 1-Propene-14C2, 2-methoxy- formulas are cited in the modification instead of a ratio, e.g., Iron, compound with uranium (Fe2235U). Labeled minerals are indexed at the systematic and mineral names, as well as at the name of the unlabeled mineral if it is studied. Labeling is indicated at the mineral name by synonym line formulas which contain isotope symbols or by modification phrases such as “labeled with boron-10” or “deuterated hydrate.” Coordination compounds (¶ 215) containing isotopic nuclear atoms are indexed at the labeled element or “ate” term, e.g., Copper-64Cu, Borate(1−)10B. Labeled ligands have the isotopic symbols appended; the ligand names are enclosed in parentheses if multiplicative prefixes are needed. Examples: D2O D2 O D2 O D2 O ND3 3+ 3+ OD 2 OD 2 Aluminum(3+), hexa(aqua-d2)-, (OC-6-11)- (see also ¶ 203 III) Al Benzoic acid, 4-(ethyl-14C)Benzoic acid, 4-ethyl-, labeled with carbon-14 Isotopically labeled inorganic compounds are named by procedures similar to those above when the unlabeled compounds have unambiguous names. Examples: DNHT P(SiD3)3 DP(O)(O−)2 H3N H 3N NH 3 NH 3 Co NH3 • 3 ClO4- Cobalt(3+), pentaammineammined3-, (OC-6-22)-, perchlorate (1:3) Ammonia-d-t Phosphine, tri(silyl-d3)Phosphonic-d acid ion(2−) Phosphoric-32P acid Phosphoric acid, sodium-22Na salt (1:3) Sulfuric acid-d Hydrochloric-35Cl acid-t Sulfur dioxide-18O Water-d2-18O Isotopes of hydro ligands, like those of hydro “substituent” prefixes for labeled organic compounds, are expressed by “d” or “t” terms placed after citation of the hydro set. Example: −H −D −D 3+ Me Al N CH2 D Me H332PO4 H3PO4 • 3 22Na Aluminum, (N,N-dimethylmethand-amine) trihydro-d2-, (T-4)- HDSO4 35 ClT 18OSO D218O In other cases labeled inorganic compounds are differentiated by synonym line formulas which contain isotope symbols. Isotopic atoms are cited after unlabeled atoms of the same element. Examples: Hydrogen sulfide (D2S) Cobalt iron oxide (CoFe2O318O) Molybdenum carbonyl (Mo(CO)4(13CO)2) Nitrogen fluoride (N15NF2) Sodium chloride (24NaCl) Sodium sulfide (Na235S) Uranium chloride (213UCl3) Salts of inorganic oxo acids with labeled cations are named in the modification by such terms as “strontium-90Sr salt (1:1)” and “ammonium-d4 salt (1:2),” but synonym line formulas are needed to indicate unsymmetrical labeling of cations or anions. Examples: Phosphoric acid calcium salt (Ca244Ca(PO4)2) Phosphoric-32P acid calcium salt (Ca3(PO4)(32PO4)) Compounds with indefinite labeled structures are indexed at the unlabeled headings with “labeled with” modification phrases. Labeled alloys are indexed like the unlabeled counterparts but with isotope symbols included in the elemental composition at each heading, e.g., Aluminum alloy, base, Al 95, 233U 5. For intermetallic compounds, synonym line 221. Mixtures. Certain mixtures are indexed like individual chemical substances and are assigned CAS Registry Numbers. These are compositions that involve components that are intentionally admixed prior to the intended uses, and remain discrete within the medium of the identified mixtures. Included are commercial products with trade or trivial names, as well as mixtures reported by authors to have particular properties or uses. Such mixtures are indexed at the name of the preferred component, with all other such components expressed in the modification of the main entry. Solvents, fillers, binders, antioxidants, stabilizers, emulsifiers, plasticizers, and flavoring and coloring agents are disregarded if not specified as “active” in terms of the intended or implied uses of the formulations. Inactive trace materials are also omitted. The percentage composition is not expressed in the index entry; thus, in the modification term “mixt. with copper(2+) sulfate (1:1),” the ratio refers to the copper sulfate, not to the mixture. Cross-references appear at trade and trivial names encountered in original documents. The preferred index entry is made at a stereoparent (¶ 202) if possible, e.g., D-Glucose or Pregn-4-ene-3,20-dione. Choices among stereoparents and nonstereoparents depend on functionality, as for molecular addition compounds (¶ 192) and polymers (¶ 222). Components are cited in the modification in alphabetical order, esters and salts being expressed in their uninverted format. The “compounds” functional subdivision is used for components that have subdivided headings. Example: Glycine, compounds mixt. with egg white and sodium chloride (NaCl) (Chemical Substance Index entry; cross-reference at Yumol) Mixtures with ten or more indexable components are indexed and registered as the individual components only with the phrase “mixt. contg.” as derivative information in the index entry. Mixtures of ten or more indexable components with trade or trivial names are indexed at the commercial name only. A mixture of salts of a single parent is indexed only once. Example: Carrageenan, hydrogen sulfate, calcium salt, mixt. with potassium and sodium salts Mixed reactants and impure reaction products are not indexed in this way, nor are unresolved natural products, mixed stereoisomers (other than pure racemates), commercially available mixtures of structural isomers, column fractions from distillations or chromatography, catalyst systems, welding fluxes, polymer blends, composites, or mixtures involved in physicochemical studies (as of phase systems) without emphasis on intended use. In these cases, separate entries are made at the headings for each significant component, with information on other components included in the index modifications (¶ 10A). ¶ 221 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Examples: Poly(oxy-1,4-phenylene-1propene-1,3-diyl) n [ − NHCO(CH 2 ) 2 − ] n [ − (SO 2 ) 2 (CH 2 ) 2 − ] n 104 Certain specific substances that are mixtures, but not regarded as sufficiently well defined to be classified as chemical substances of unique composition, are identified by headings in the General Subject Index. Examples are Air, Copper ores, Gasoline, Granite, Peanut oil, Petroleum. 222. Polymers. Classes of polymers, natural and synthetic, are indexed in the General Subject Index. Specific polymers are named on the basis of the monomers from which they are formed and/or on the basis of their structure, as represented by a structural repeating unit (SRU). Since original documents do not always provide sufficient structural information to allow generation of the SRU name, the method most frequently used for describing polymeric substances is by citation of the component monomers. A few commercial polymers, each of which accounts for a large number of index entries, are indexed only at the SRU-based systematic polymer name. Systematic nomenclature is discussed first in the following paragraphs, followed by monomer-based polymer nomenclature. Systematic (SRU) nomenclature for polymers has been adapted from the system developed by the Committee on Nomenclature of the Division of Polymer Chemistry of the American Chemical Society5. Names derived by this system, in addition to monomer-based entries, are cited for polymers whose structural repeating units are well-documented or can confidently be assumed. “Expected,” “idealized,” or “drawn-for-convenience” SRUs are not given systematic polymer names. Occasionally, when there is no information on the component monomers in the original document, an entry derived from the SRU name is the only index entry available. The SRU is named by citation of one or more multivalent radicals of regular substitutive nomenclature. Many of these radical names will be found in the Illustrative List of Substituent Prefixes (Section H, ¶ 294); others are supplied in the various sections dealing with classes of compounds from which the radicals are derived. The SRU name is enclosed in parentheses or brackets, and prefixed by the term “Poly”. Each multivalent radical retains its own numbering and is oriented, if possible, so that the point of attachment written at the left end of the repeating unit is assigned the lowest possible number. This permits the naming of the SRU in a directional manner, reading from left to right. The largest possible multivalent radicals are chosen as all or part of the name, and naming proceeds from left to right, starting with the most preferred multivalent radical. (See the following sections for the choice of most preferred radical.) Unsaturation and substituents are indicated by appropriate locants. Functional derivatives, such as esters and hydrazones and oxides of hetero atoms which are an integral part of the repeating unit are expressed by prefixes rather than by modification terms, and are numbered as low as possible while preserving the preferred names of the parent radicals. Salts of acids and anions of quaternary “-onium” compounds, and oxides of hetero atoms which are an integral part of the repeating unit are cited following the name of the SRU. The number of free valencies between units is minimized; i.e., unsaturated radicals are preferred. Polymers of unspecified length and chains of reported “average” length, are named by the methods described above. The prefix “oligo-” is not used to differentiate polymers of relatively low molecular weight from high polymers. When, however, the number of structural repeating units is exactly specified, the oligomer is usually named according to the principles of substitutive nomenclature. Examples: ( − CH 2 − ) n ( − CHMeCH 2 − ) n ( − CH=CH − ) n (not (=CHCH=) n ) [ − (CO) 2 (CH 2 ) 2 − ] n —O CH =CH CH 2 — Poly[imino(1-oxo-1,3-propanediyl)] Poly(disulfonyl-1,2-ethanediyl) Poly[oxycarbonyloxy(methyl-1,2ethanediyl)] (The position of the methyl group is not assumed in this polyester from carbonic acid and 1,2-propanediol.) ( — O CO 2 CH 2 CH 2 — ) n { —O + Me −H SO2 O CM e 2 n Poly[oxy-1,4-phenylenesulfonyl1,4-phenyleneoxy-1,4-phenylene(1-methylethylidene)-1,4phenylene] (With equal numbers of atoms between the oxygen atoms in two possible arrangements, the preferred path includes the other hetero atom, sulfur, as early as possible.) [ − O CH 2 SN H ( CH 2 ) 2 O CH 2 SCH 2 N H CH 2 − ] n Poly(oxymethylenethioimino-1,2ethanediyloxymethylenethiomethyleneiminomethylene) (With equal distances between the two oxygen atoms and between the oxygen and sulfur atoms, the direction is determined by the shortest distance between the oxygen atom and the hetero atom of third preference (nitrogen).) — NHCO NHCO CONH CO N H ( C H 2 ) 6— n Poly(methylene) Poly(1-methyl-1,2-ethanediyl) Poly(1,2-ethenediyl) (not Poly(1,2ethanediylidene)) Poly(1,2-dioxo-1,4-butanediyl) (not Poly(1,4-dioxo-1,4-butanediyl)) Poly(3-methyl-1-butene-1,4-diyl) 5 1 1′ Poly(iminocarbonyl-1,4-phenyleneiminocarbonyl-1,3-phenylenecarbonylimino-1,4-phenylenecarbonylimino-1,6-hexanediyl) (The citation proceeds in the increasing order of distances between the nitrogen atoms: 5,5,5, and 6 intervening carbon atoms.) 5′ ( − CH=CHCHMeCH 2 − ) n S N 3 S N 3′ For more complex examples, further criteria for arranging the components of an SRU are required. The descending order of priority of citation (and of structuring of the SRU) is (a) heterocyclic rings, (b) acyclic hetero atoms in the order: O, S, Se, Te, N, P, As, Sb, Bi, Si, Ge, Sn, Pb, B, Hg, (c) carbocyclic rings, (d) acyclic carbon chains. If substituents are present, otherwise identical parent radicals in the SRU are chosen by the principles, in turn, of maximum number, lowest locants, and earliest alphabetical order of substituents. The shortest path (smallest number of atoms) is taken from the most preferred multivalent radical to another occurrence of the same radical (if present) within the SRU, then to the next most preferred radical, and so on. N=N n Poly([2,2′-bithiazole]-4,4′-diyl-1,4phenylene-1,2-diazenediyl-1,4phenylene) [ − NHCOCH(CO 2 Pr) − ] n Poly[imino[1-oxo-2-(propoxycarbonyl)-1,2-ethanediyl]] (not Poly[imino(1-carboxy-2-oxo-1,2ethanediyl)], propyl ester) Poly[(dimethyliminio)-1,2ethanediyl bromide (1:1)] (the ionic derivative term is included in the SRU) Structure-based Nomenclature for Linear Polymers”, Macromolecules 1968, 1(3), 193-198. The IUPAC recommendations (Pure Appl. Chem. 1976, 48, 373-385; 1993, 65 (7), 1561-1580) are in full agreement with CAS practice. The IUPAC term “constitutional repeating unit” (CRU) corresponds to CA’s SRU. 5“A — N + M e 2 ( CH 2 ) 2 — • Br − n 105 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 222 When SRUs are bridged only by metals, systematic polymer nomenclature is not used; instead, the substance is indexed either at the monomeric salt name or by coordination nomenclature (¶ 215), with a modification phrase, in either case, such as “homopolymer” or “polymer with” (see below). End groups, when known, are specified by means of appropriate radical names, together with Greek letters “α-” and “ω-” expressed as substituents. The α-end group is the group attached to the left end of the SRU when the structure is ordered by the specified rules; it is cited first, regardless of alphabetical order. Examples: Cl−(CH2)n−CCl3 Poly(methylene) α-chloro-ω-(trichloromethyl)Poly(1,1-difluoro-1,2-ethanediyl) α-(trichloromethyl)-ω-chloro- Cl3C−(CF2−CH2−)nCl are not assigned systematic names; they are indexed at the monomer names only. The previous paragraphs described a systematic nomenclature for polymers of well characterized structure, and for polymers whose structural repeating unit (SRU) can be confidently assumed. The latter are restricted to (a) polyamides from a dibasic acid (or derivative) and a diamine, or from an amino acid or lactam; (b) polyesters from a dibasic acid (or derivative) and a dihydric alcohol, or from a hydroxy acid or lactone; (c) polyurethanes from a diisocyanate and a dihydric alcohol; and (d) polycarbonates from carbonic acid (or an ester or halide) and a dihydric alcohol. Polymers manufactured from known monomers are generally indexed at the monomer names whether or not systematic (SRU) entries are also made. An exception is the treatment of a few very common industrial polymers, e.g., nylon 6, nylon 66, terephthalic acid polymer with ethylene glycol, which, to preclude inordinate repetition of a large number of index entries at various names assigned SRU names. Example: Terephthalic acid See 1,4-Benzenedicarboxylic acid 1,4-Benzenedicarboxylic acid, polymers polymer with 1,2-ethanediol—see Poly(oxy-1,2-ethanediyloxycarbonyl-1,4-phenylenecarbonyl) A cross-reference appears also at 1,4-Benzenedicarboxylic acid, esters, 1,4dimethyl ester, polymer with 1,2-ethanediol; and two corresponding crossreferences at 1,2-Ethanediol, polymers. Polymers from a single monomer are indexed at the monomer name with the term “homopolymer” cited in the modification. (The terms “peptides,” “polyamides,” and “polyesters” are not used for specific homopolymers at monomer headings.) Examples: (BuCH=CH 2 ) n Linear double-strand (“ladder” and “spiro”) polymers may sometimes be named as a chain of quadrivalent radicals. Two pairs of locants, separated by a colon, indicate the distribution of bonds. Example: —CH 2 CH— CH— —CH 2 n Poly(1,4:2,3-butanetetrayl) When a ladder polymer must be named as an SRU of one or more quadrivalent radicals linked through one or more bivalent radicals (here, these terms are extended to mean radicals attached to four or two different atoms, not only to radicals with four or two free valence bonds) the direction of citation is from the most favored quadrivalent radical by the shortest path to the next most favored quadrivalent radical, and so on; then toward the most favored bivalent radical. Rings are broken (a) to minimize the number of free valencies of the total “mer,” (b) to maximize the number of most preferred hetero atoms in the ring system, (c) to maintain intact the most preferred ring system (¶ 138). End groups, when known, are identified by α and α′ (at the left terminus as the structure is drawn) and by ω and ω′ (at the right terminus) as locants for substituent prefixes, e.g., α,α′-dihydroxy-ω,ω′-dihydro-. Examples: 1-Hexene, homopolymer (only index entry) 2-Propenoic acid, 2-methyl-, tridecyl ester, homopolymer (only index entry) Undecanoic acid, 11-amino-, homopolymer (the Formula Index entry appears at C11H23NO2 ; a systematic entry is also made at the assumed SRU name: Poly[imino(1-oxo-1,11-undecanediyl)], (C11H21NO)n) [H 2 C=CMeCO 2 (CH 2 ) 12 Me] n [H 2 N(CH 2 ) 10 CO 2 H] n 4 5 1 8a n Poly(2,3:6,7-naphthalenetetrayl6-methylene) O 4 5 7 8 O N N O O 14a N 1 14 N 12 O 11 n O Poly([1,4]dioxino[2,3-b]-1,4-dioxino[2′,3′:5,6]pyrazino[2,3-g]quinoxaline-2,3:9,10-tetrayl9,10-dicarbonyl) (The same number of free valences can be expressed by breaking the oxygen ring or the partially saturated hydrocarbon ring; the latter course keeps intact the maximum number of heterocyclic rings.) Poly[1,3-dioxa-2-silacyclohexane5,2-diylidene-2,2-bis(oxymethylene)] (not Poly[1,3-dioxa-2silacyclohexane-2,5-diylidene5,5-bis(methyleneoxy)] (The direction is determined by the shortest path from the hetero atom in the ring to the acyclic hetero atom.) Polymers formed from two or more monomers are indexed at the preferred monomer name with the modification term “polymer with” followed by the other monomer names in alphabetical order. No attempt is made to indicate the percentage composition of copolymers. Ratios typically refer to specific monomer salts. The preferred index name is determined by the usual rules for selection of a heading parent (¶ 138) but a stereoparent is preferred over a nonstereoparent, e.g., D-Glucose, polymer with butanedioic acid. For identical heading parents, the choice is determined by (a) maximum number of substituents, (b) lowest locants of substituents, (c) maximum number of occurrences of the index heading parent (in a multiplicative name), (d) earliest index position of the index heading. When the choice is dependent on modification terms, it is determined as follows: (a) underivatized heading preferred over derivatives cited in the modification; thus, a free acid is preferred over an ester; (changes in format caused by elevation of modification terms into the heading for purposes of subdivision are ignored in applying this rule; thus Acetic acid is preferred over Acetic acid ethenyl ester); (b) class of derivative in the descending order: anhydride, ester, hydrazide, hydrazone, oxime; (c) largest number of (most preferred) derivative; thus, monoester preferred over dioxime preferred over monooxime; (d) lowest expressed locants of derivative terms; thus, for 1,2,4-Benzenetricarboxylic acid, a 1,2-diester is preferred over a 1,4-diester; (e) the earliest alphabetical order; thus, “ethyl ester” preferred over “propyl ester.” Examples: 1(a) 2(a) 1-Heptene, polymer with 1-hexene 2-Propenoic acid, butyl ester, polymer with 1-ethenyl-4-methylbenzene and 2,5-furandione 6 1 O 2 O Si O n O 3 Peptides of established structure are indexed at systematic peptide names such as Glycine, glycylglycyl- (see ¶ 206). Peptides of unknown structure are indexed as polymers. Example: [HO 2 CCH(NH 2 )(CH 2 ) 2 CO 2 CH 2 Ph] n Linear polymers composed of SRUs within SRUs, e.g., [-[O(CH2)2]m-O2C(CH2)4CO2-]n L-Glutamic acid, 5-(phenylmethyl) ester, homopolymer ¶ 222 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 2-Propenoic acid, 2-methyl-, homopolymer, 9-anthracenylmethyl ester 2-Propenoic acid, 2-methyl-, decyl ester, homopolymer, hydrolyzed Poly[1-(4-sulfophenyl)-1,2-ethanediyl], propyl ester 106 and the assumed structural repeating unit: Poly[imino[(2S)-1-oxo-2-[3-oxo-3(phenylmethoxy)propyl]-1,2ethanediyl]] n —N H C O C H | (C H 2 ) 2 CO 2 CH 2 Ph When more than one amino acid is present and the sequence is unknown, a copolymer is indexed, and named at the preferred amino acid monomer. Alternating, block, and graft polymers are distinguished from random polymers by indexing as copolymers at the monomer names. The term “alternating”, “block”, or “graft” (or a combination thereof) is cited in a special modification after all other structural information but before descriptive phrases relating to properties, uses, etc. The more specific block terms, diblock, triblock, tetrablock, and pentablock are also used. Differentiation between the polymeric substrate and the applied monomer is not made; e.g., whether 1-hexene is grafted on 1-heptene homopolymer or vice versa, the index entry is at 1Heptene, polymer with 1-hexene, graft. The term “random” is not employed by CA in indexing specific polymers. Siloxanes prepared by hydrolytic polymerization of chlorosilanes are indexed at the monomer names with the term “hydrolytic” cited in the modification to indicate the essential role of water in forming a polymer chain of -Si-Ounits. The term “hydrolytic” is used in addition to the term “homopolymer” or “polymer with”. Example: Benzene, 1,1′-(dichlorosilylene)bis-, polymer with dichlorodimethylsilane, hydrolytic Polymers of specific compounds with classes of compounds are indexed at the specific monomers in the Chemical Substance Index and at the class name, e.g., Aldehydes or Nitriles, in the General Subject Index. Example: 1-Hexene, 5-methylpolymer with unsatd. nitriles Nitriles unsatd.; polymers with 5-methyl-1-hexene Formaldehyde homopolymers containing only oxymethylene repeating units are indexed only at the heading Poly(oxymethylene) in the Chemical Substance Index. Commercial and impure polyformaldehydes are indexed at Polyoxymethylenes (a plural class heading in the General Subject Index) unless author emphasis is centered on Paraformaldehyde. Formaldehyde copolymers are indexed as polymers formed from two or more monomers (except Formaldehyde copolymers with Phenol, Urea, or 1,3,5-Triazine-2,4,6-triamine. Oligomers of definite structure are indexed as specific compounds by the regular principles of index nomenclature. When the precise structure is not known but the number of units is specific, “dimer,” “trimer,” etc., is expressed in the modification at the name of the monomer. The term “oligomeric” may be cited after “homopolymer” or “polymer with . . .” if this aspect is stressed in the original document. Telomers with a definite structure are named systematically. Examples: Cl-(CH2)6-CCl3 Cl-(CF2-CH2)n-CHCl2 Ethenol (vinyl alcohol) polymers that are indexed at that heading are exceptions (they are prepared by hydrolysis of ethenol ester polymers). Acetals of ethenol homopolymer and ethenol polymers with ethenyl acetate are indexed at the homopolymer or copolymer with the term “cyclic acetal” followed by the specific aldehyde name in the modification. Additional entries appear in the General Subject Index at the trivially named class terms, Polyvinyl acetals and Polyvinyl butyrals. Acetals of other ethenol polymers and acetals with unspecified aldehydes are indexed at the underivatized polymer and at the class term with a modification term, e.g., chlorinated benzals, to indicate the type of acetal when appropriate. Molecular addition compounds of polymers are indexed in the usual way (¶ 192), e.g., Ethenesulfonic acid, homopolymer, compd. with 4-ethenylpyridine homopolymer. The preferred name is cited at each molecular formula in the Formula Index. (See ¶ 198) Polyethylene and polypropylene glycols are indexed as specific compounds when the precise structure is reported and not more than ten repeating units are present, e.g., 3,6,9,12,15-Pentaoxaheptadecane-1,17-diol, hexamethyl-. The position of methyl substituents is not assumed; if it is reported, locants are cited. Glycol polymers of eleven units or more are indexed at Poly(oxy-1,2ethanediyl), α-hydro-ω-hydroxy-, and Poly[oxy(methyl-1,2-ethanediyl)], α-hydro-ω-hydroxy-. The class term Polyoxyalkylenes in the General Subject Index is used as an additional entry for all specific polyalkylene glycols except when the alkanediyl group is ethanediyl or propanediyl and for cases where the nature of the alkanediyl group is unknown. When it is known, the SRU can be named specifically; thus, Poly[oxy(2-phenyl-1,3-propanediyl)], α-hydro-ω-hydroxy-. Polyethylene-polypropylene glycols are named as copolymers: Oxirane, 2-methyl-, polymer with oxirane. Esters and ethers of polyalkylene glycols containing not more than ten repeating units are indexed by the regular principles of substitutive nomenclature. For larger polymers, the ester or ether is expressed as a substituent at the SRU-based heading. Mono derivatives are cited in the α-position, with ω-hydroxy at the other terminus. Dissimilar diesters or diethers are expressed in alphabetical order. Ester-ethers have the acyl group or the inorganic-type ester, including borono, phospho, sulfo, substituted sulfonyl groups, etc., assigned to the α-position, and the ether at the ω-end. When appropriate information is lacking, an ester or ether term is cited without locant. When multiplying radicals must be employed, they are given α-locants. Examples: nOH Me(CH2)16CO O(CH2)2 Poly(oxy-1,2-ethanediyl), α-(1-oxooctadecyl)-ω-hydroxy- Ac O(CH2)2 O2 CCMe = CH2 n Heptane, 1,1,1,7-tetrachloroH2C = CHCO O(CH2)2 Poly[oxy-1,2-ethanediyl], α-acetyl-ω-[(2-methyl-1-oxo2-propen-1-yl)oxy]n O(CH2)11Me Poly(1,1-difluoro-1,2-ethanediyl), α-chloro-ω-(dichloromethyl)- Telomers of unknown structure are indexed as copolymers with the term “telomer with . . .” cited in the modification. Example: 1-Hexene, telomer with tetrachloromethane Post-treated polymers are described by modification terms after the polymer has been described. Examples: 2-Propenoic acid, homopolymer, sodium salt (No ratios are used for polymer salts unless specific stoichiometry is possible and is specified.) Benzenamine, 4-ethenyl-, polymer with ethenylbenzene, hydrochloride (No ratios are used for polymer salts unless specific stoichiometry is possible and is specified.) 1,4-Dioxane-2,5-dione, 3,6-dimethyl-, homopolymer, copper(2+) salt (2:1) (The polymer chain has only one carboxy group and one hydroxy group a specific salt ratio is possible.) Poly(oxy-1,2-ethanediyl), α-(1-oxo-2-propen-1-yl)-ω(dodecyloxy)Me(CH 2 ) 16 CO 2 (CH2)2O O(CH2 )2 O2 C(CH2 )16 Me m n Poly(oxy-1,2-ethanediyl), α,α′-1,4-phenylenebis[ω-[(1oxooctadecyl)oxy]- Polynucleotides (cf. Nucleotides, ¶ 210) are indexed as “homopolymer” or “polymer with . . .” at the “-ylic acid” monomers (5′-isomers). Examples: 5′-Adenylic acid, homopolymer Cytidine, 5′-O-phosphonoadenylyl-(3′→5′)-, homopolymer 5′-Guanylic acid, polymer with 5′-adenylic acid and 5′-cytidylic acid 107 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 223 Polynucleotides in which different primary chains are associated intermolecularly by hydrogen bonds are indexed as molecular addition compounds (the modification term “complex” is used in this special case); e.g., 5′-Adenylic acid, homopolymer, complex with 5′-uridylic acid homopolymer (1:1). In more complicated cases, a combination of policies is applied. Examples: zine is employed instead of 21H,23H-5,10,15,20-Tetraazaporphine, and its fused tetrabenzo derivative is 29H,31H-Phthalocyanine. Radicals are formed in the regular way; e.g., 21H,23H-porphin-2-yl, 29H,31H-phthalocyanine2,9,17,24-tetrayl. The metal complexes, including the biologically important porphyrin iron and magnesium complexes (hemes and chlorophylls) are indexed as coordination compounds (¶ 215) with italic letter locants to indicate coordinating atoms. Example: Me − −p−A−p−G−p−U−p−A−p−G−p−C−p−U−p−A−p−G−p−U− O 2C( CH 2) 2 1 20 19 −O 2 C( CH 2 ) 2 CH =CH 2 6 − 4 Me 9 Guanosine, 5′-O-phosphonoadenylyl-, (3′→5′)- polymer with 5′-cytidylic acid and 5′-uridylic acid −p−A−p−G−p−A−p−A− −p−U−p−U−p−C−p−U− − N 21 22N HO — Fe 3+ − N24 23 N 16 14 • 2H+ 11 5′-Guanylic acid, polymer with 5′-adenylic acid, complex with 5′-uridylic acid, polymer with 5′-cytidylic acid (1:1) CH =CH 2 Me Me Trade names are frequently used for polymers and are cross-referred to specific polymers if the components can be structurally defined. If the polymer components are unknown, or only partially known, or cannot structurally be defined, an index citation is made at the trade name and at the appropriate polymer class name. Natural rubber is indexed at the General Subject Index heading Natural rubber and chlorine-treated rubber at Chlorinated natural rubber. When a synthetic rubber is indexed at Butadiene rubber, Isoprene rubber, etc., no additional entry will be found in the printed Chemical Substance Index, but for studies indexed at Synthetic rubber, Urethane rubber, or at Polysulfide rubber, information will also be found, when available, at the appropriate printed chemical compound or polymer heading, with “rubber” cited in the index modification. Examples: Synthetic rubber styrene-vinyl bromide (General Subject Index entry) Benzene, ethenyl-, polymer with bromoethene, rubber (preferred Chemical Substance Index entry) For studies indexed at Rayon, Acetate fibers, etc., no additional index entries will be found, but for studies of fibers of specific chemical composition entered at Polyamide fibers, Synthetic polymeric fibers, etc., additional information is entered at the appropriate chemical substance name, except where a cross-reference to the fiber class appears. Example: Synthetic polymeric fibers adipic acid-butanediol (General Subject Index entry) Hexanedioic acid, polymer with 1,4-butanediol, fiber (an additional Chemical Substance Index entry is made at the SRU name.) Stereochemistry of polymers is expressed by special modification terms when the necessary information is reported; such terms include isotactic, syndiotactic, threo-diisotactic, erythro-diisotactic, and disyndiotactic. The term “atactic” (for a random configuration) is not employed by CA in indexing specific polymers. In addition to the special terms above, polymer stereochemistry is defined, when appropriate, by the regular descriptors E, Z, R, and S (¶ 203 I). For commercial elastomeric polymers, which cannot generally be assumed to be stereochemically homogeneous, terms such as “1,2-configuration,” and “cis-1,4configuration” are included in the descriptive portions of index modifications, but are not made part of the unique preferred CA index names. 223. Porphyrins and Bile pigments. The porphyrins embrace all cyclic tetrapyrroles in which single methene groups link pairs of pyrrole rings. The parent 21H,23H-Porphine is used, with a suffix to express principal groups if present, for all derivatives, including hydrogenated derivatives, unless an author emphasizes the absence of hydrogen at the 21- and 23-positions. Example: 18 17 24 23 20 1 3 Ferrate(2−), [7,12-diethenyl3,8,13,17-tetramethyl-21H,23Hporphine-2,18-dipropanoato(4−)κN21,κN22,κN23,κN24]hydroxy-, hydrogen (1:2), (SP-5-13)(cross-reference from Hematin) Phorbine is a cyclopentaporphine derivative: 20 21 1 18 16 22 2 4 Phorbine 6 NH 23 24 N 26 25 N 14 13 HN 8 11 9 Indicated hydrogen is not expressed with Phorbine, which contains six saturated centers. Removal of hydrogen is indicated by dehydro terms, e.g., Phorbine, 3,4-didehydro-. Metal complexes, radicals, etc., are named as for the analogous porphine derivatives. Example: H C=CH 10 12 − Me Et N 15 + 24 17 18 Me 7 N 25 26 5 N 2 Mg 2 23 −N 1 22 • Me Me − Magnesate(1-), [(3S,4S,21R)-9-ethenyl14-ethyl-21-(methoxycarbonyl)4,8,13,18-tetramethyl-20-oxo-3phorbinepropanoato(3-)-κN23,κN24, κN25,κN26]-, hydrogen (1:1), (SP-4-2)H+ (cross-reference from Chlorophyllide a) O 2 C( CH 2 ) 2 21 M e O2 C 20 O Bile pigments are indexed at 21H-Biline, the numbering system of which derives from that of porphyrin (the carbon atom involved in ring closure, C-20, is omitted from the numbering system). 18 19 17 24 23 1 3 N HN 15 21 22 5 N 13 12 10 N 7 8 21H-Biline All derivatives, including hydrogenated derivatives, are indexed at 21HBiline unless hydrogen is absent at the 21-position, in which case the 22H-parent is preferred over lower positions. The (all-Z) stereochemistry shown in the diagram above is assumed. The 1,19-dihydroxy derivatives are tautomeric with the dioxo compounds, which are preferred in indexing. Example: Me 19 OO 1 CH =CH 2 Me 21 4 22 6 5 CH 2 =CH 16 15 N N 11 24 23 HN N HN 15 21 22 21H,23H-Porphine 5 7 14 N 9 10 Me Me NH 13 12 10 N 8 21H-Biline-8,12-dipropanoic acid, 2,17-diethenyl-1,10,19,22,23,24hexahydro-3,7,13,18-tetramethyl-1,19-dioxo(cross-reference from Bilirubin) ( CH 2 ) 2 CO 2 H ( CH 2 ) 2 CO 2 H Porphyrin analogs containing additional hetero atoms are indexed by organic replacement nomenclature (¶ 127) at such names as 21H-5-Thiaporphine and 21H,23H-5,15-Diazaporphine. The trivial name 21H,23H-Porphyra- For derivatives of Corrin, see Vitamin B12 (¶ 224). ¶ 224 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Examples: 1 6 108 224. Vitamins, being structurally diverse, are indexed by more than one method. The headings Vitamin B, Vitamin K, etc., are used to index groups of compounds having similar physiological activities, especially for biological studies. Such headings as Vitamin B4, Vitamin B6, Vitamin F, may each refer to one or more specific compounds or to nothing more than an ill-defined vitamin activity. They are used in indexing when employed in original documents, and CAS Registry Numbers are assigned to them. Vitamin A is a heading parent employed for the group of A vitamins and for vitamin A activity in general. Vitamin A1 is indexed at the carotenoid heading Retinol (¶ 212); Vitamin A2 is indexed at Retinol, 3,4-didehydro-. Related trivially named heading parents are Retinoic acid and Retinal. In all these cases, an all-trans-configuration about the double bonds is implied by the names. Abnormal stereochemistry is specifically cited in the modification. Vitamin B is a heading parent employed for the B-complex and vitamin B activity in general. Vitamin B1 and related compounds are indexed at the systematic names. (The trivial name Thiamine, not used as a CA index heading, implies presence of a chloride anion.) Example: NH 2 N Me N Me + CH2 — N S • Cl − N Me H O CH 2 CHO OH 4-Pyridinecarboxaldehyde, 3hydroxy-5-(hydroxymethyl)-2methyl- 1 N H O CH 2 6 Me OH CH 2 N H 2 3-Pyridinemethanol, 4-(aminomethyl)-5-hydroxy-6-methyl- ( CH2 ) 2 OH 6 1 N Me Thiazolium, 3-[(4-amino-2methyl-5-pyrimidinyl)methyl]5-(2-hydroxyethyl)-4-methylchloride (1:1) H O CH 2 OH CH 2 O H 3,4-Pyridinedimethanol, 5hydroxy-6-methyl- The diphosphoric (pyrophosphoric) acid ester of Vitamin B1 (cocarboxylase) is indexed by expressing the ester as an “a”-named substituent; i.e., the 5(2-hydroxyethyl) group becomes 5-(4,6,6-trihydroxy-4,6-dioxido-3,5-dioxa4,6-diphosphahex-1-yl)-. Vitamin B2 contains a ribitol residue and is indexed at the stereoparent Riboflavin: ′ C H 2 OH 4′ 3′ Vitamin B12 is an index heading used for the vitamin itself: H 2NCO(CH 2 ) 2Me Me H 2NCOCH 2 Me Me H H2NCOCH 2 CH 2 NHCO(CH 2 ) 2 Me Me CN N|N Co 3+ N N − CH 2 CO N H 2 ( CH 2 ) 2 CO N H 2 − 5 Me Me ( CH 2 ) 2 CO N H 2 H O —C —H H O —C —H H O —C —H Me 9 1′ 2′ Riboflavin CH2 1 N 10a N N 4 3 O NH CHMeOP(O) (O −) O OH N N Me Me HOCH 2 O Me 6 5 O Plain locants are employed for ring substituents, primed locants for the ribitol moiety. Binary headings analogous to those for nucleotides (¶ 210) are used for phosphates, diphosphates (pyrophosphates), etc., e.g., Riboflavin 5′(dihydrogen phosphate). Functional derivatives of Riboflavin are expressed in the modification, e.g., 2′,3′,4′-triacetate, other derivatives as substituents. Analogs in which ribitol is replaced by other alditols are indexed at the alditol stereoparent names, e.g., D-Galactitol, 1-deoxy-1-(3,4-dihydro-7,8-dimethyl-2,4-dioxobenzo[g]pteridin-10(2H)-yl)-. Vitamin B3 is indexed at 3-Pyridinecarboxamide; Vitamin B5 is a littleused term for Pantothenic acid, which is indexed at β-Alanine: H O C H 2 C Me 2 C H (OH) CONH( CH 2 ) 2 CO 2 H Vitamin B12 β-Alanine, N-[(2R)-2,4-dihydroxy-3,3dimethyl-1-oxobutyl)-] Vitamin B6 is a heading parent employed for studies in which the precise compound is not further specified. The individual compounds and their derivatives are indexed systematically at pyridine headings. The terms Cyanocobalamin and Cobalamin are not used in index names. Derivatives, other than functional derivatives, of Vitamin B12 are indexed largely in accordance with rules of the International Union of Pure and Applied Chemistry,6 which should be consulted for details. The fundamental ring system is Corrin, which is numbered like Porphyrin, the locant “20” being omitted to facilitate analogous treatment of derivatives; the methene bridges which remain are numbered “5,” “10,” and “15.” The index heading (in the General Subject Index) for this class of compounds is Corrinoids, and specific compounds are generally indexed at the largest appropriate heading parent chosen from the following: Cobyrinic acid, Cobinic acid, Cobamic acid, or the corresponding amides. 6IUPAC, “Nomenclature of Corrinoids (Rules approved 1975)”, Pure Appl. Chem. 1976, 48, 495-502; Biochemistry 1974, 13, 1555-60. 109 (b) Me Me Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 RCOCH2 )2 Me Me CH 2 COR (c) (d) ( CH2 )2 COR N − N Co 3 N + ¶ 224 ( a ) R C O CH 2 H ( g ) R C O C H2 (f) R C O (C H2 ) 2 1 N Me Me Me Me ( CH2 )2 COR ( e ) Derivatives are named in accordance with the rules for carbohydrates (¶ 208), e.g., L-Ascorbic acid, 5,6-O-(1-methylethylidene)-; L-threo-2,3-Hexodiulosonic acid, γ-lactone (cross-reference from L-Dehydroascorbic acid).Vitamin D is an index heading used for vitamin D activity in general. Vitamin D1 is a molecular addition compound of Vitamin D2 and (3β,9β,10α)ergosta-5,7,22-trien-3-ol (lumisterol). Vitamins D2 and D3 are given systematic names. Vitamin E is used as a heading for Vitamin E activity in general. Individual compounds, notably α-tocopherol, exhibiting this activity are indexed systematically. Example: Me Me O (CH2)3 Me Me HO Me (CH2)3 Me (CH2)3 CHMe2 R= R1 = OH R= R1 = NH2 R= OH; R1= NHCH2CHMeOH R= OH; R1= NHCH2 CHMe | OP (O) (O ) O − Cobyrinic acid Cobyrinamide acid Cobinic acid (in Cabinamide, R= NH2) Cobamic acid (in Cobamide, R= NH2) OH OH O HOCH 2 2H-1-Benzopyran-6-ol, 3,4-dihydro2,5,7,8-tetramethyl-[(4R,8R)-4,8, 12-trimethyltridecyl]-, (2R-) In Cobamic acid and Cobamide, the structures (above) have been shown as inner salts; the cobalt(3+) nucleus is also coordinated with the nitrogen atoms with loss of one proton overall. The compound therefore still possesses a 1+ charge. Similarly, Cobyrinic and Cobinic acids (and their amides), which lack the phosphate group, have a 2+ charge, and can form dihydroxides, cyanide hydroxides, etc. Partial amides of Cobyrinic acid are designated by use of the small italic locants shown in the diagram above; e.g., Cobyrinic acidabcdeg-hexamide, dicyanide. Substitution on amide groups is indicated by N with a superscript, e.g., Nf-(carboxymethyl)-. In modifications at corrinoid headings, the various types of derivatives are cited in the following order: (a) groups linked to the cobalt atom, e.g., Co-ammine, Co-methyl deriv., Co-(pyridine); followed by anions, e.g., cyanide, acetate (salt); and then “hydrate” if present; (b) lactones and lactams formed between acetic or propanoic residues and existing or added hydroxyl and amino groups; (c) esters of the corrin moiety, e.g., dihydrogen phosphate (ester); (d) “inner salt” (for zwitterionic structures); (e) further ester terms for a polybasic acid residue such as phosphoric acid, e.g., “3-ester with. . . .” When the cobalt is in a 2+ rather than a 3+ oxidation state, Ewens-Bassett numbers (¶ 215) or Stock numbers are cited in the heading; e.g., CobinamideCo(1+), Co-ethyl deriv., hydrate (1:1) (the “1+” designation belongs to the entire cobinamide parent, and results from coordination of the Co(2+) atom with loss of a proton from corrin; the modification term renders the total compound neutral); Cobamide-Co(II) (the Stock number is employed because no charge remains; a proton has been lost from corrin and another from the phosphoric acid group by inner salt formation). Analogs of Cobyrinic acid, etc., in which cobalt is replaced by another metal are named by substituting a suitable term for “Co-” in the original name. Thus, the iron(2+) and nickel(3+) analogs of cobyrinic acid are named Ferrobyrinic acid and Nickelibyrinic acid, respectively. The hydrogen analog is Hydrogenobyrinic acid. Vitamin C is indexed at L-Ascorbic acid: O =C H O —C O H O —C H —C H O —C —H C H 2O H Vitamin K is used as a group heading; the specific compounds are named systematically. Examples: O Me Me Me CHMe2 ( C H2 ) 3 Me O (CH2) 3 ( C H2 )3 1,4-Naphthalenedione, 2-methyl-, 3-[(2E,7R,11R)-3,7,11,15-tetramethyl-2-hexadecen-1-yl]- O Me H C=C CH 2 O Me 6 CH 2 H 1,4-Naphthalenedione, 2-[(2E,6E,10E, 14E,18E)-3,7,11,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaen-1-yl]-3-methyl- L-Ascorbic acid ¶ 225 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 G. CHEMICAL SUBSTANCE NAMES FOR RETROSPECTIVE SEARCHES 110 Introduction Acetals Acid halides Acids Additive Nomenclature Alcohols and Phenols Aldehydes Alkaloids Alloys Amides Amidines Amines Amino acids Anhydrides Azo and azoxy compounds Boron compounds Carbohydrates Carbonic acid and relatives Coordination compounds Diazo compounds Dyes Elementary particles Enzymes Esters Ethers Formazan Functional derivatives Guanidine and relatives Hydrazine Hydroxylamine Imines Index name selection Indicated hydrogen Inorganic compounds Inositols Iodine compounds Isocyanides ¶ 225 226 227 228 228A 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 Ketene Ketones Locants Metallocenes Mixtures Molecular addition compounds Multiplicative prefixes Nitriles Nitrone Nucleosides and Nucleotides Onium compounds Order of precedence of compound classes Organometallic compounds “Oxo” acids Peptides Peroxides Phosphorus compounds Polymers Porphyrins and Bile pigments Replacement (“a”) nomenclature Replacement nomenclature for functions Ring systems Salts Silicon compounds Spelling Stereochemistry Stereoparents Steroids Substituent prefixes (radicals) Sulfur compounds Sulfones and Sulfoxides Tautomers Terpenes Thiols Urea Vitamins Zwitterionic compounds ¶ 261 262 263 264 265 265A 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 281A 282 283 284 285 286 287 288 289 289A 290 291 292 293 293A 225. Introduction. The current name-selection policies for chemical substances described in Sections A through F above were introduced in 1972. These policies, which are now well-established, enable the index user to derive preferred CA names for substances of specific molecular structure and thereby to find information about them in current and recent indexes. However, in carrying searches back beyond 1972, difficulties can arise. The current CA name of our compound has been determined; but where will we find this same substance in older CA indexes? Cross-references in these indexes are helpful, but of course none exist that lead from current names to those in Eighth (and earlier) Collective Indexes. As a last resource, the Formula Indexes can be consulted. But a simpler method, especially in searching for groups of compounds, is to read the appropriate paragraphs of this section. Although published originally (in the Volume 76 Index Guide under the title “Ninth Collective Index Changes”) to alert index users to prospective changes, it will now be found most serviceable to remind retrospective searchers of the main nomenclature changes occurring in 1972. For example, ¶ 228 (below) indicates that peroxoic acids, in Volume 75 and earlier indexes, will be found at Peroxy headings, that aldehydic, anilic, and hydroxamic acid headings were also employed, and that many acids were indexed at trivial names; ¶ 270 explains that cationic compounds currently indexed at aminium headings were formerly entered at Ammonium; and ¶ 281 gives examples of current and former names for cyclic epoxides. The changes in name selection policies described in this section are 1972 changes unless otherwise specified. The very few revisions found necessary in the Tenth (1977-1981) and Eleventh (1982-1986) Collective Index periods mainly affect inorganic compounds and are described in ¶¶ 239, 257, and 273. Changes in name-selection policies for the Twelfth (1987-1991) and Thirteenth (1992-1996) Collective Index periods affect alloys, carbohydrates (lactams), coordination compounds, formazans, index name-selection (multiplicative names), inorganic compounds (line formulas of clusters, intermetallic compounds), molecular addition compounds (common components; hydrates), nitrilimines, onium compounds (free radicals), peptides, phosphonium ylides, phosphoryl-halides and halogenoids, polymers (block, graft, and hydrolytic), ring systems (list of common systems), salts (list of common anions), stereochemistry (sign of optical rotation), and zwitterions (inner salts, sydnones). These are described in this section at their respective paragraphs listed above. The changes for the Fourteenth (1997-2001) Collective Index periods affect coordination nomenclature, stereochemical practices, and stereoparents and are described in ¶ ¶ 242, 284, and 285. The arrangement of subjects is alphabetic, and references are supplied in each case to the paragraphs in Sections A through F where a complete account of current policies will be found. The index (Section M) may also be consulted. Headings found in current indexes are shown in boldface within the following paragraphs. 226. Acetals are indexed like ethers (¶ 196); thus, Acetone, diethyl acetal became Propane, 2,2-diethoxy-. Cyclic acetals, except those of stereoparents (¶ 202), are indexed at the ring names. Epoxides are likewise indexed at the names of the appropriate ring systems, e.g., Oxirane. 227. Acid halide names (¶ 170) were affected by the discontinuance of most trivial acid names. Isocyanates, isothiocyanates, and isocyanides are now named like the halides. In the following examples, names prior to 1972 are shown in parentheses. Benzenepropanoyl chloride Butanethioyl fluoride Benzenesulfonyl isocyanate (Hydrocinnamoyl chloride) (Butyryl fluoride, thio-) (Benzenesulfonic acid, anhydride with isocyanic acid) 228. Acids. Carbonic acid and related compounds including Formic acid (¶ 183) are now relegated to a position below “organic” acids and above inorganic “oxo” acids (¶ 106). Among carboxylic acids, the only trivial names retained were Acetic acid and Benzoic acid. (When oxygen in the functional group of these two acids is replaced, systematic functional replacement names, e.g., Ethanimidic acid, Benzenecarbothioic acid, are employed.) All other organic acids (carboxylic, sulfonic, sulfinic, etc.) are named systematically (¶ 165); e.g., Propanoic acid (formerly Propionic acid); Benzoic acid, 2-hydroxy- (Salicylic acid); 2Butenedioic acid (2E)- (Fumaric acid); Benzenesulfonic acid, 4-amino- (Sulfanilic acid). Use of replacement affixes (¶ 129) for modified carboxylic, sulfonic, etc., groups was extended for Volume 76. In the following examples, the names formerly used are shown in parentheses: Ethanimidothioic acid 3-Pyridinecarbohydrazonic acid, methyl ester Butanediperoxoic acid 2-Propanesulfeno(thioperoxoic) acid (Acetimidic acid, thio-) (Nicotinic acid, methyl ester, hydrazone) (Peroxysuccinic acid) (Peroxy-2-propanesulfenic acid, thio-) Aldehydic, amic, anilic, hydroxamic, hydroximic, nitrolic, and nitrosolic acids are now named as derivatives of carboxylic acids, amides, etc. Examples: 1-Naphthalenecarboxylic acid, 8-formylPropanoic acid, 3-amino-3-oxoButanoic acid, 4-oxo-4-(phenylamino)Acetamide, N-hydroxyEthanone, 1-nitro-, oxime See also Oxo acids (¶ 273). (Naphthalaldehydic acid) (Malonamic acid) (Succinanilic acid) (Acetohydroxamic acid) (Acetonitrolic acid) 111 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 241 228A. Additive Nomenclature. The terms oxide, sulfide, selenide, and telluride are used as part of the modification to describe the presence of a chalcogen atom attached to trivalent antimony, arsenic, bismuth, nitrogen or phosphorus, or to divalent sulfur, selenium, or tellurium (¶ 123). However, acceptable unambiguous locants are often lacking to describe the exact location when multiple possibilities are present and the result is a name which is less specific than the structure. Effective with Volume 124, oxides, etc. attached to the parent portion of the name continue to be cited as oxide, sulfide, etc., with an appropriate locant in the modification portion of the name, however, if the attachment is not to the parent, terms such as oxido, sulfido, selenido, or tellurido will be cited with locants, in the substituent or modification, as appropriate. 229. Alcohols and Phenols (¶ 175) are treated as of equal seniority in the order of chemical functions; previously, alcohols (in which the hydroxyl group is formally attached to a saturated carbon atom) were placed just ahead of phenols. Now, the preference of cyclic over acyclic hydrocarbons (¶ 138) often causes a change of nomenclature unless a conjunctive name can be used. Examples: OH Phenol, 3-[(hydroxymethyl)thio](formerly Methanol, [(m-hydroxyphenyl)thio]SC H 2 O H CH2OH OH Benzenemethanol, 2-hydroxy(formerly Benzyl alcohol, o-hydroxy-) (the preferred heading parent is larger than Phenol) Radicofunctional names previously used for unsubstituted Ethyl through Dodecyl alcohol were replaced by Ethanol, 1-Propanol, etc. Iso-, sec- and tert-names are no longer used, except to index “isooctanol,” etc., when no further information is provided. Isopropyl alcohol is now indexed at 2-Propanol; sec-Butyl alcohol at 2-Butanol; and tert-Butyl alcohol at 2-Propanol, 2-methyl-. Phenol was retained as a heading parent, but all other trivially named phenols, including polyhydric benzene derivatives, are named systematically at such names as Phenol, 2-methyl- (formerly o-Cresol) and 1,3,5Benzenetriol. Naphthalenol (formerly Naphthol) and Anthracenol (formerly Anthrol) are now spelled out. 230. Aldehydes (¶ 173) are named systematically by use of the suffixes “-al” and “-carboxaldehyde,” except for the three trivial names Acetaldehyde, Formaldehyde, and Benzaldehyde. Chalcogen analogs are all named systematically. Examples (previous index names are on the right): Propanal Benzaldehyde, 2-hydroxy-3-methylBenzenecarbothioaldehyde Butanedithial (Propionaldehyde) (2,3-Cresotaldehyde) (Benzaldehyde, thio-) (Succinaldehyde, dithio-) Ethanamine, N-ethyl- (formerly Diethylamine). Amino derivatives of the hydrides Borane, Phosphorane, and Stannane are now indexed at Boranamine, Stannanediamine, etc. 236. Amino acids (¶ 205) which are biologically significant are usually indexed at the trivial (or “common”) names which are now classed as stereoparents. A few trivial names of α-amino carboxylic acids (Allocystathionine, Carnosine, Creatine, Cystathionine, Ethionine, Hippuric acid, Lanthionine, Pantothenic acid, Sarcosine, Thyronine, Thyroxine) and all trivial names of amino sulfonic acids were discontinued. The configurational descriptor is now placed in the heading as a prefix, thus: L-Leucine. The new stereoparent Phenylalanine is now employed, instead of Alanine, phenyl-, for C6H5CH2CH(NH2)COOH. Amino acid radicals are now employed only in naming peptides. O- and S-Derivatives of hydroxyl- and mercapto-group-containing amino acids, e.g., Serine and Cysteine, are now indexed at those heading parents. Esters of stereoparent amino acids with systematically named hydroxy compounds are indexed at the stereoparents. An ester with another stereoparent is indexed at the component possessing the higher function. Normally, only one entry is now made for each ester (¶ 247). Beginning in 1992, primed locants are assigned to the side-chain methyl group of isoleucine, alloisoleucine, leucine, valine, and isovaline. Such branched-chained derivatives of these acids are no longer named as derivatives of the linear acid (Butanoic acid or Norvaline). 237. Anhydrides (¶ 179) of unsubstituted monobasic organic acids prior to Volume 76 (1972) were named in the heading, e.g., Acetic anhydride; now they are cited in the modification at the acid heading. Anhydrides of organic acids with inorganic monobasic oxo acids are named at the organic acid heading with an “anhydride with...” phrase in the modification, not at such former headings as Acetyl nitrate, but anhydrides of organic acids with isocyanic and isothiocyanic acids are treated like the corresponding acid halides. The term “bimol. monoanhydride” is employed when appropriate, with locants before the second word if necessary, at polybasic organic acid headings. Cyclic anhydrides are now indexed as diones at the oxygen heterocycle names. Heading parents such as Dicarbonic, Dicarbonimidic, and Tricarbonic acid are used for carbonic acid anhydrides and their analogs (¶ 183). Anhydrides of phosphonic, phosphorous, arsonic, and arsonous acids are now treated like phosphoric acid anhydrides, e.g., Diphosphonic acid. “A” names are used for anhydrides when the requirements (¶ 127) are met. 238. Azo and azoxy compounds (¶ 193) in the absence of higher functions (e.g., nitrogen heterocycles, or functions expressible by a suffix) are indexed at Diazene, HN=NH (formerly Diimide). Azobenzene thus became Diazene, diphenyl-, and Naphthalene-2-NNO-azoxymethane became Diazene, methyl2-naphthalenyl-, 1-oxide. Prior to 1992, formazans were of higher functionality than azo and azoxy compounds, but now have no special rank (¶ 249). 239. Boron compounds (¶¶ 159, 182). Cyclic compounds in which ligands bridge two boron atoms are named as coordination compounds; for example, Diazoniadiboratacyclobutane H2 N H2B N H2 BH 2 231. Alkaloids (¶ 204). Many alkaloids indexed prior to 1972 at trivial names are now indexed systematically. The remaining trivial headings (stereoparents) are limited to alkaloids exhibiting stereochemical complexity. Class A alkaloids (named systematically) therefore comprise a much larger group than previously, when it was restricted to compounds containing no asymmetric center. Classes B and C are largely unchanged, except that the number of Class B alkaloid stereoparents (“systematic” alkaloid names) has been greatly increased with a consequent reduction in the number of Class C alkaloid stereoparents (trivial names for alkaloids of known constitution, including all stereochemistry). Class D alkaloids (those not fully elucidated) are indexed at systematic names without stereodescriptors if sufficient information is available, otherwise at author names or as Class B stereoparents with partial stereochemical information. 232. Alloys (¶ 214) are now indexed and registered as specific chemical substances. The components, if known, are cited as symbols in the modification with their percentage compositions (when present to the extent of 0.1% or more). Cross-references from trade names and some code designations have been provided (without percentage compositions); e.g., Alnico V. See Iron alloy, base, Fe,Al,Co,Cu,Ni,Si,Ti (Alnico V). Beginning in 1992 “nonbase” headings, e.g., Cobalt alloy, nonbase, for the other component elements are no longer made. For alloys of unknown percentage composition, only the “nonbase” headings for the components are employed. 233. Amides (¶ 171) are named systematically by use of the suffixes “-amide” and “-carboxamide.” The three remaining exceptions are Formamide, Acetamide, and Benzamide, but their chalcogen and imidic analogs are now named systematically; for example, Acetamide, thio- is named as Ethanethioamide. Anilides are now indexed as N-phenyl amides. Secondary and tertiary amides are named at the preferred primary amide name. Thio analogs of sulfonamides are named as sulfonothioamides and sulfonodithioamides. See also Urea (¶ 292). 234. Amidines (¶ 171) are indexed systematically as imidamides, i.e., as amides of imidic acids; thus, Formamidine in Volume 76 became Methanimidamide. Amidoximes are named as N-hydroxy imidamides. 235. Amines (¶ 176) are all named systematically; Aniline is indexed at Benzenamine; Methylamine became Methanamine. Derivation of amine names for amino derivatives of nitrogen heterocycles is now permitted; Pyridine, 2-amino- (pre-1972 name), is now 2-Pyridinamine; and Piperidine, 4-(2aminopropyl)-, became 4-Piperidineethanamine, α-methyl-. Secondary and tertiary amines are named as derivatives of the preferred primary amines, e.g., is now indexed at Diborane(6), di-µ-amino-. Derivatives of polyboranes are given low numbers for substituents regardless of the direction of numbering. Boronic acid is treated as an independent index heading parent; thus, Benzeneboronic acid was renamed Boronic acid, phenyl- in 1972. Since the Tenth Collective Index period (1977-81), most molecular addition compounds of boron have been indexed as coordination compounds. From the same date, Hypoboric acid, ((HO)2BB(OH)2), has been indexed at Diborane(4), tetrahydroxy-. 240. Carbohydrates (¶ 208). Glycosides of known constitution are now indexed at the systematic names; they are ranked as polyhydric alcohols, not as aldehydes or ketones, and when attached to a carbon atom of an aglycone containing a higher chemical function are indexed at a name which expresses that function. N-Glycosyl derivatives of heterocycles have continued to be indexed at the heterocyclic parents. Radical (substituent prefix) names are no longer formed from alditols. Oligosaccharides indexed prior to Volume 76 at common names, e.g., Sucrose, are now named by systematic carbohydrate nomenclature. The names Erythrose and Threose were discontinued except in the naming of polysaccharides. “Arrow” nomenclature was extended to all tri- and higher oligosaccharides, including those indexed at “-oside” heading parents. Configurational descriptors (D-, L-, and DL-) are now always placed ahead of the heading parent; e.g., D-Glucopyranoside. The index parent Cellulose acetate was discontinued; entries since 1972 have been made instead at Cellulose, esters, with modifications such as “monoacetate,” “diacetate,” and (for the indefinite ester) “acetate.” The naming of intramolecular amides of carbohydrate acids as lactams was discontinued for the Twelfth Collective Index. Such amides are named systematically as heterocyclic derivatives (¶ 171). 241. Carbonic acid and relatives (¶ 183) underwent name changes in several respects. Carbonic acid itself was retained but is now classed below all “organic” acids, including carboxylic and sulfonic acids, and above inorganic oxo acids (¶ 106). It is the parent of numerous acids, amides, acid halides, etc., derived from it by the use of affixes and suffixes. Thus, Carbonic acid, thio-, became Carbonothioic acid; Imidocarbonic acid, HN=C(OH)2, became Carbonimidic acid; Formic acid, chlorothio-, hydrazone, H2NN:C(Cl)SH, became Carbonochloridohydrazonothioic acid. Cyanic acid, Thiocyanic ¶ 241 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Examples: Lepton Meson, π− (140) Muon, µ+ (106) Nucleon resonance N*(2040) Positron leptonic mol. with chlorine (e+e-Cl0) Proton 112 acid, etc., were retained. Carbamic acid was kept as an acceptable abbreviated version of Carbonamidic acid; the abbreviation is also employed when other affixes are present, as indicated in the following list of revised names. Carbamic acid Carbamohydrazonic acid Carbamimidic acid Carbamothioic acid, S-ethyl ester Carbamo(dithioperox)imidic acid H2NCO2H H2NC(=NNH2)OH H2NC(=NH)OH H2NC(O)SEt H2NC(=NH)SSH 246. Enzymes (¶ 218) are now indexed as chemical substances to which CAS Registry Numbers are assigned. These are inverted if they consist of more than one word. Examples: Dehydrogenase, lactate Phosphatase, adenosine triAsparaginase Papain The heading may contain further information regarding secondary activities, etc.; thus: Dehydrogenase, malate (decarboxylating). 247. Esters (¶ 185). Some changes were made in the list of “Class I” (i.e., common) acids. The following acids were added: Benzoic acid, amino- (all isomers) Carbamic acid, N-methylCarbonic acid Phosphorodithioic acid Phosphorothioic acid Inorganic oxo acids other than Boric acid (H3BO3), Nitric, Phosphoric, Phosphorous, Sulfuric, and Sulfurous acids were removed from the Class I list and therefore are now preferred as the heading parents for esters with Class I and Class II alcohols. (Additional entries for esters were discontinued.) Cyclic esters are named as heterocycles. Esters of stereoparents with systematically named acids are indexed at the stereoparents (¶ 202). The use of a radical term ending in “-yl ester” is now preferred to “ester with...,” even when the alcoholic component contains a chemical function higher than alcohol (see ¶ 250), unless the latter phrase is followed by a stereoparent, as in “5′-ester with adenosine,” or by an acid requiring a synonym line formula, as in “triester with boric acid (H3BO3).” When the “-ate” form of a polybasic acid name is cited in the modification at an alcohol heading, all free acid groups are denoted by the word “hydrogen,” e.g., Cyclohexanol, 4bromo-, dihydrogen phosphate. Esters of substituents of index heading parents are expressed as substituents. Thus, the acetate of Benzenesulfonic acid, 4-hydroxy- is named Benzenesulfonic acid, 4-(acetyloxy)-, and the methyl ester of Pyridinium, 3carboxy-1-methyl-, chloride, is indexed at Pyridinium, 3-(methoxycarbonyl)-1-methyl-, chloride (1:1). Ortho esters are named as ethers, i.e., as alkyloxy and aryloxy substituents. Organic replacement “a” names are used for esters where appropriate (¶ 127). 248. Ethers (¶ 196) are named as substituents of hydrocarbons and other index heading parents; Ether as a heading parent was discontinued. Thus, Ethyl ether became Ethane, 1,1′-oxybis-. Polyethers may often be named by organic replacement nomenclature (“a” names) (¶ 127). Methylenedioxy derivatives of benzene and its hydrogenated derivatives are named at 1,3-Benzodioxole. 249. Formazan (¶ 193) was retained in 1972, but was ranked just below imines as the highest of the nitrogen compound classes lacking functional suffixes. Formazan radicals were also retained. However, beginning with the Thirteenth Collective period formazan, in all its aspects, is named systematically (¶ 193). 250. Functional derivatives (¶ 112) (now restricted to acyclic anhydrides, esters, hydrazides, hydrazones, and oximes) of principal chemical functions have continued to be expressed in the index modifications at boldface index headings, but derivatives of subsidiary functions are usually included in the substituent prefixes which follow the comma of inversion in an inverted heading. Hence Benzoic acid, p-hydroxy-, ethyl ester, acetate, is now named Benzoic acid, 4-(acetyloxy)-, ethyl ester (¶ 185). Esters are always expressed by use of an “-yl ester” phrase when possible, not by an “ester with” phrase, unless a stereoparent or an acid which requires a synonym line formula is being cited in a modification. Prior to Volume 76, “ester with” was used when the alcoholic component contained a higher functon; now, “ester with glycolic acid” becomes “carboxymethyl ester.” 251. Guanidine and relatives. Guanidine (¶ 183) was retained as an index heading parent for Carbonimidic diamide with the locants shown (numerical locants were formerly employed): H 2 N C( =N H ) N H 2 N N ′′ N′ Carbonic acids with a single hydrazide residue replacing an acid group are indexed, not as Carbonohydrazidic acid derivatives, but at Hydrazine index heading parents such as Hydrazinecarboxylic acid. The dihydrazide is named Carbonic dihydrazide. Phosgene, C(:O)Cl2, is indexed at Carbonic dichloride. Carbonic acid is now a “Class I” acid in the naming of esters (¶¶ 185, 247) as are Formic acid, Carbamic acid, Carbamic acid, methyl-, and Carbamic acid, phenyl-. 242. Coordination compounds (¶ 215). Beginning in Volume 76 (1972), the stereochemistry (when known) of mononuclear coordination complexes has been described in the index name modification by capital italic letter symbols (¶ 203 III). The ligating atoms of ligands, with certain limitations, are denoted by capital italic element-symbol locants for mononuclear complexes and for nonbridging ligands of polynuclear complexes. Use of these locants has resulted in a change in some simple inorganic ligand names; thus nitrito became (nitritoκO) and nitro became (nitrito-κN). Delocalized ligands are now denoted by the “hapto” convention, in which the Greek letter eta (η) is employed, along with locants to indicate the particular ligand atoms involved, or else a superscript indicating the total number of such atoms (when all are involved). Compounds containing more than one complex anion are indexed at the preferred anion while other anions are cited with (simple) cations in the modification. Ligands containing ester groups now normally include the esters in the ligand names. The rules for choice of a radical name for a ligand, rather than a name ending in “-ato,” underwent some modification. Enclosing marks are employed around all “-ato” ligand names, and additional enclosing marks are added for bridging ligands when the ligand name itself requires enclosing marks; e.g., [µ-(acetato-κO:κO′)]. Beginning in Volume 106 (1987) salts of dithio(seleno, telluro) organic acids and polythio(seleno, telluro) arsenic and phosphorus acids with coordination metals are structured and named at the chelated forms. Metal “radical” names, e.g., “aluminio,” are no longer employed for attachment of one metal to another in a binuclear complex, or as multiplicative radicals (¶ 194). Numerical prefixes gave way to numerical ratios when mixed cations and anions (or at least one multivalent ion) are expressed in the modification. The terms “ion(1+),” “ion(2+),” etc., are not cited in modifications. Beginning in Volume 126 (1997), the Kappa system replaces the donor atom system for describing the position of ligand attachment to a coordination center. In the Kappa system, when it is necessary to indicate the attachment of a ligand to a coordination center, the ligating atom(s) are indicated by the italic element symbol of the atom(s) preceded by a Greek Kappa (κ). This combination of italic element symbol and Greek Kappa is placed after that portion of the index name to which it directly applies; e.g., (2-aminoethanolato-κO). Beginning with Volume 129, some substances which have had coordination names will receive ring names. Old Name Sulfur, mercaptomethylperoxy-, (T-4)New Name Dioxathiirane, 3,3-dihydro-3-mercapto-3-methyl243. Diazo compounds, including diazohydroxides, etc., are now often named at Diazene headings (¶ 193). Example: Diazenecarbonitrile, 2-(4-chlorophenyl)- (formerly Benzenediazocyanide, p-chloro-) Cl N= NCN The unsubstituted radical HN=N− is now named diazenyl (formerly diazeno). 244. Dyes (¶ 216) of known constitution are now always indexed at their systematic names. Previously, azo dyes and a few other classes were given C.I. (Colour Index) names for indexing purposes. Mixed dyes are indexed (like other mixtures, ¶ 221) at the names of their components when these are known. C.I. names are employed, when available, for dyes of unknown composition. 245. Elementary particles (¶ 217) are now indexed and registered as chemical substances. It is ranked below Urea (carbonic diamide). Biguanidine is now named 1,2-Hydrazinedicarboximidamide with the locants shown: H 2 N C( =N H ) N H N H C( =N H ) N H 2 N N′ 1 2 N ′′′ N ′′ It ranks as the amide of a diimidic acid of a nitrogen acyclic parent, e.g., above 113 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 265A Benzenedicarboximidamide but below Benzamide. Biguanide and Triguanide are now named systematically as Imidodicarbonimidic diamide and Diimidotricarbonimidic diamide, respectively. 252. Hydrazine (¶ 193) was retained as a trivial name for Diazane, and functional suffixes may be appended to it; thus, Hydrazinecarboxylic acid, H2NNHCO2H (formerly Carbazic acid), ranks above monocarboxylic acids derived from carbon skeletons. Hydrazides (¶ 189) and hydrazones (¶ 190) of principal chemical functions expressed in the heading parent are cited in the modification as before, but these derivatives of functions expressed as substituents are now “named through” as in the case of esters (¶¶ 247, 250), by use of hydrazinyl and hydrazinylidene radicals. Diacyl hydrazines are now indexed not at Hydrazine but as acyl hydrazides of the preferred acid (¶ 189). Semicarbazones of nonstereoparents are no longer indexed as such but as derivatives of Hydrazinecarboxamide, either as an index heading parent or as an appropriate substituent. Semioxamazones are treated as alkylidene hydrazides of Acetic acid, 2-amino-2-oxo-, RCH:NNHC(:O)C(:O)NH2. The heading parent Carbonic dihydrazide (¶ 183) was introduced for H2NNHC(O)NHNH2 (formerly Carbohydrazide) and its derivatives, including compounds previously indexed as carbohydrazones of oxo parents. 253. Hydroxylamine (¶ 193) was retained as a heading parent; it ranks low among nonfunctional nitrogen parents between Hydrazine, H2NNH2, and Thiohydroxylamine, H2NSH (formerly Hydrosulfamine). N-Acyl derivatives of Hydroxylamine are now indexed at amide headings; N-alkyl derivatives at amine names. In the absence of N-substituents, O-derivatives are usually indexed at Hydroxylamine. Alkylidene derivatives are indexed as oximes of the corresponding carbonyl compounds unless higher functions are present, in which case a (hydroxyimino) substituent prefix is employed (see ¶ 195). 254. Imines (¶ 177) are indexed by means of the suffix “-imine” appended to the molecular skeleton, which may now be a nitrogen heterocycle; e.g., 4(1H)-Pyridinimine (formerly Pyridine, 1,4-dihydro-4-imino-). Cyclic imines are indexed at the ring names; e.g., Aziridine (formerly Ethylenimine). Imines rank below amines and all other compounds expressed by functional suffixes. 1-Iminoalkyl radicals are so named, not as imidoyl radicals; hence, formimidoyl has become (iminomethyl), and propionimidoyl is indexed as (1-iminopropyl). 255. Index name selection policies for chemical substances (¶ 138) were revised for Volume 76 and subsequent volumes as follows: (a) “Like treatment of like things” was abandoned. (b) The principle of “complexity” (a measure of the number of parentheses and brackets in a name) is no longer employed. (c) The principle of “lowest locants” of substituents on an index heading parent (¶¶ 137, 138) was introduced on a regular basis. (d) The principle of “centrality” is now applied when a compound contains a sequence of three or more occurrences of the same heading parent. (e) Conjunctive nomenclature (¶ 124) was extended for the first time to benzene with a single acyclic functional substituent, as in Benzenemethanol (names such as Benzenediacetic acid were used previously). It was discontinued for compounds in which ring attachment is by a double bond, and for Carbamic and Sulfamic acids, unsaturated acyclic functional compounds, and acyclic difunctional compounds. (f) Multiplicative nomenclature (¶ 125) based on hydrocarbons is now permitted, as in Ethane, 1,1′-oxybis-, and Benzene, 1,1′-[1,2-ethanediylbis(thio)]bis-. The terms “bis,” “tris,” etc., not “di-,” “tri-,” etc., are always employed in multiplying a parent. The use of two-part unsymmetrical multiplying radicals prior to 1972 meant that names such as (ethylidenesilylene) could be misconstrued to be either CH3CH=Si= or −CH(CH3)−SiH2−. Thus, in 1972 the use of “ylidene” radicals in combination with other bivalent radicals in forming names of multiplying radicals was forbidden. Now, stringent symmetry is required of compounds for which multiplicative names may be used, and thus, beginning in 1994 such combinations in forming multiplying radicals are no longer prohibited (¶ 125). (Ethylidenesilylene) can only represent CH3CH=Si= in a multiplicative CA index name. Beginning with Volume 119, the principle of selection of a parent based on preferred atomic content (¶ 138(b)) is also applied to a choice between two acyclic skeletons named by organic replacement nomenclature (“a” names). 256. Indicated hydrogen (¶ 135) is always cited, never implied; thus, Indene became 1H-Indene, and Fluorene is now named 9H-Fluorene. Hydrogen not required for formation of a ring system, but “added” at the same time as a functional (or radical) suffix is now described as “added hydrogen” (¶ 136). In tautomeric systems (¶ 122), lowest locants for indicated hydrogen are normally preferred; thus 1H-Purine, not 7H-Purine, is indexed in the absence of information to the contrary. 257. Inorganic compounds (¶ 219) are largely indexed at names previously used. Binary names for derivatives of elements possessing hydride names were changed to derivatives of the hydrides; e.g., Silane, tetrachloro- (formerly Silicon chloride (SiCl4)); Borane, trifluoro- (formerly Boron trifluoride). When the compound is the halide of a recognized acid, it is so named; e.g., Phosphorous trichloride (formerly Phosphorus chloride (PCl3)). Pyrophosphoric acid, (HO)2P(O)OP(O)(OH)2, was renamed Diphosphoric acid, and analogous compounds are named similarly; for example, Diphosphoryl chloride, Cl2P(O)OP(O)Cl2; P,P′-Diamidodiphosphoryl fluoride, (H2N)FP(O)OP(O)F(NH2); P′-Amidodiphosphoric(III,V) acid, (HO)2POP(O)(OH)(NH2). Since the Tenth Collective Index period (1977-81), antimony has been classed as a metal, and synonym line formulas have been cited in index headings with all binary salt-type names, e.g., Sodium chloride (NaCl). See also ¶¶ 239, 273. Graphite derivatives have been indexed as molecular addition compounds instead of at the pre-1977 headings Graphitic acid, Graphite nitrate, etc. Beginning in 1982, elements of atomic number 104 and above have been indexed at names derived from these numbers, e.g., Unnilquadium (formerly Element 104). Starting with Volume 122, for elements 104-109, CAS follows the recommendations of the ACS Committee on Nomenclature: 104 - Rutherfordium (Rf); 105 - Dubnium (Db); 106 - Seaborgium (Sg); 107 - Bohrium (Bh); 108 Hassium (Hs); and 109 - Meitnerium (Mt). Likewise, starting with Volume 139, element 110 is called Darmstadtium (Ds). Starting in 1987 inorganic line formulas may be expressed with decimals or numerical ranges as well as integers, e.g. Aluminum gallium arsenide (Al0.15Ga0.85As). For intermetallic compounds, beginning in 1992, additional entries for the metals with the less alphabetically preferred names are discontinued. 258. Inositols (¶ 209) are now indexed at the separate stereoparents derived by combining individual configurational prefixes with the name Inositol, e.g., myo-Inositol; scyllo-Inositol. These names in turn are preceded by the configurational descriptors D- and L-. When a choice must be made for derivatives, the earliest alphabetic prefix is preferred; then the prefix D- is selected, rather than L-; finally, lowest locants are assigned to substituent prefixes. Inosose and Streptamine are retained as stereoparents. 259. Iodine compounds (¶ 188) with abnormal valencies are indexed by coordination nomenclature (¶ 215); e.g., Iodine, dichlorophenyl- (formerly Benzene, (dichloroiodo)-. 260. Isocyanides (¶ 188). Alkyl isocyanides, RNC, are now indexed substitutively; acid isocyanides are treated like acid halides. For example, Isopropyl isocyanide became Propane, 2-isocyano-; 2-Naphthalenecarbonyl isocyanide was formerly indexed at 2-Naphthoic acid, anhydride with hydroisocyanic acid. 261. Ketene (¶ 174) is now indexed systematically at Ethenone; Ketene, thio- at Ethenethione. Cyclic ketenes are named as cycloalkylidene (etc.) derivatives of the new heading parent Methanone, H2CO. Unsubstituted H2CO is still indexed at Formaldehyde, but unsubstituted CH2S is named Methanethial. In the presence of chemical functions higher than ketone, the =CO radical is named carbonyl (if the carbon atom does not form part of an acyclic chain) or as (oxoalkyl). The isolated =CS radical is named carbonothioyl if both free valencies are attached to a single atom, or if it is used in a multiplying prefix; otherwise as (thioxomethyl). 262. Ketones (¶ 174). All trivial names (including Acetone, Chalcone, Benzil, Benzoin, and all flavone, quinone, phenone and naphthone headings) were abandoned. The heading parent Ketone was discontinued. Methanone, H2C:O, is used to index ketones having two ring systems directly attached. The analogous headings Methanethione, H2C=S, etc., were introduced. Acetone was changed to 2-Propanone, Acetophenone to Ethanone, 1phenyl-, Acetophenone, thio- to Ethanethione, 1-phenyl-, Anthraquinone to 9,10-Anthracenedione, Benzil to Ethanedione, diphenyl-, Flavone to 4H-1Benzopyran-4-one, 2-phenyl-, and Uracil to 2,4(1H,3H)-Pyrimidinedione. For a discussion of this last name, see ¶ 289A. The ketone function is no longer overstepped; hence Ethanone, 1,1′-(1,5naphthalenediyl)bis- (formerly Naphthalene, 1,5-diacetyl-). 263. Locants (¶¶ 114, 137). The locants o-, m-, and p- were replaced by Arabic numerals in all cases; as-, s-, and ν- were likewise replaced, except in as- and s-Indacenes and their fused derivatives. Locants for unsaturation are now always cited for molecular skeletons of three or more atoms except for monocyclic hydrocarbons containing one multiple bond. Polyvalent radicals with free valencies located at two or more positions now have all locants cited; thus, ethylene became 1,2-ethanediyl. In ring assemblies, locants for positions of attachment are always cited except for two-component assemblies of cycloalkenes, cycloalkadienes, etc. Thus, 4-Biphenylamine became [1,1′-Biphenyl]-4-amine. In multiplicative names, locants are always cited to indicate the position of attachment of the multiplying radical to the heading parent. Special rules whereby locants for fully halogenated compounds and radicals were sometimes omitted are now discontinued. Urea is now assigned the locants N- and N′- in place of 1- and 3- (¶ 183). When locants are required for derivatives, e.g., esters, cited in modifications, all such locants are used (¶ 119). Letter locants are now employed with ligand names in coordination nomenclature to define the ligating atoms (¶ 215). 264. Metallocenes (¶ 215), including Ferrocene and its derivatives, are now considered to be neutral coordination complexes. Suffix-type names and conjuctive names are no longer used; hence Ferrocenecarboxylic acid is now indexed at Ferrocene, carboxy-; and 1,1′-Ferrocenediacetic acid at Ferrocene, 1,1′-bis(carboxymethyl)-. 265. Mixtures (¶ 221) are now indexed and registered as individual chemical substances if they are considered significant in their own right, e.g., pharmaceutical and pesticide mixtures which possess trade names, or mixtures which are emphasized in an original document as possessing special properties. Ingredients which are considered to be inactive within the intended use of a mixture are disregarded, e.g., solvents, fillers, and inactive trace components. Ratios of components are not cited. Cross-references from trade names, etc., are provided; e.g., Terracoat. See 1,2,4-Thiadiazole, 5-ethoxy-3-(trichloromethyl)-, mixt. with pentachloronitrobenzene. 265A. Molecular addition compounds (¶ 192). Ten additions were made to the list of common components for the Twelfth Collective Index. The new additions are Acetic acid, trifluoro-; Acetonitrile; Benzene; Benzene, methyl-; Benzenesulfonic acid; Benzoic acid; Borate(1-), tetrafluoro-, hydrogen; Ethanamine, N,N-diethyl-; Methane, dichloro-; and Pyridine. ¶ 265A Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 114 The prefixes hemi- and sesqui- were replaced by the ratios (2:1) and (2:3), respectively in names of hydrates and ammoniates for the Twelfth Collective Index. Beginning with the Thirteenth Collective Index period, restriction of the expression of the number of molecules of solvation to fifteen (pentadeca) is abandoned. Fractional coefficients are limited to two digits in both the numerator and the denominator. Beginning with the Fifteenth Collective period, molecular addition compounds are indexed at the preferred name only. The preferred name appears in the Formula Index at the formula of each of the components. See ¶ 192 for the components for which no name is printed in the Formula Index. Beginning with the Sixteenth Collective period, ratios are used for all molecular addition compounds for which stoichiometry is expressed. Because polymers are nonstoichiometric compounds, ratios are rarely used for molecular addition compounds of polymers. 266. Multiplicative prefixes (¶ 110). Bis-, tris-, etc., are used in multiplicative names instead of di-, tri-, etc., even when the heading parent is not otherwise substituted. Bis-, tris-, etc., are used with methylene in every circumstance in general index nomenclature (but “di-O-methylene” is used with sugar names), and with oxy and thio, etc., to denote a multiplicity of single chalcogen atoms; thus, [methylenebis(oxy)] denotes −O−CH2−O−, while (methyldioxy)- denotes CH3−O−O−. Bi-, etc., names for ring assemblies were discontinued for assemblies of rings joined by double bonds. All ring-assembly names are enclosed in brackets when followed by a suffix; derived radicals are treated similarly. Binaphthyl and Bianthryl become Binaphthalene and Bianthracene (see ¶ 281). Bi-, etc., names derived from acyclic compounds, e.g., Bicarbamic acid, Triguanide, are discontinued. 267. Nitriles (¶ 172). Only the trivial names Acetonitrile and Benzonitrile are retained; otherwise, changes in nitrile names are almost entirely parallel to those for the carboxylic acids (¶ 165) from which they and their names are derived. Thus, Hydrocinnamonitrile became Benzenepropanenitrile. Cyanamide was retained for H2NCN, but conjunctive “-carbamonitrile” names were discontinued. +− The zwitterionic nitrilimines (RC ≡ N − N − R ′ ) are named as substituted hydrazinium hydroxide inner salts (¶ 201) beginning in the Twelfth Collective period. 268. Nitrone, H2C=NH=O, was renamed Methanimine, N-oxide (¶ 177); N-alkyl nitrones are indexed as oxides at amine index heading parents; N-acyl nitrones at amide headings. 269. Nucleosides and Nucleotides (¶ 210) have continued to be indexed at trivial names, e.g., Adenosine, Cytidine, although the purine and pyrimidine bases from which they are derived are now named systematically; e.g., Cytosine is indexed at 2(1H)-Pyrimidinone, 4-amino- (¶ 122). N-Acyl derivatives of nucleosides are indexed at the nucleoside parents instead of at amide names, but higher functions have continued to be indexed at the parents which express them. Substituents are now expressed at nucleotide headings, e.g., 5′-Uridylic acid, 2′-amino-2′-deoxy-3′-thio-. Mixed phosphate esters are indexed at the preferred phosphate heading rather than at the plain nucleoside name; e.g., Inosine 5′-(trihydrogen diphosphate), 2′-(dihydrogen phosphate). Nucleosides and nucleotides are considered to be stereoparents (¶ 203), and their esters with systematically named substances are therefore indexed at nucleoside or nucleotide index heading parents. 270. Onium compounds (¶ 184). Ammonium compounds are named from the corresponding preferred amines by use of “-aminium” as a suffix and expression of the remaining groups as N-substituents; e.g., Ethanaminium, Nethyl-N,N-dimethyl-, iodide (1:1) (formerly Ammonium, diethyldimethyl-, iodide). Naming of cyclic quaternary nitrogen compounds and other cationic species, e.g., sulfonium compounds, is largely unchanged. Localized cationic free radicals centered on hetero atoms (¶ 184) were named as derivatives of the index heading parents Ammoniumyl, Oxoniumyl, Sulfoniumyl, etc. prior to the Thirteenth Collective period. 271. Order of precedence of compound classes (¶ 106) has continued to play an important role in the selection of a preferred index name. Changes include the following: (a) The heading parent Silane now ranks below cyclic carbon parents and above acyclic carbon parents. This change does not apply to any other silicon parents. (b) More emphasis is placed on the presence of a principal chemical functional group (expressed as a suffix attached to a molecular skeleton). Thus Ethanamine (a functional compound) is ranked above Quinoline (a nonfunctional molecular skeleton). (c) Ferrocene and other metallocenes are ranked with neutral coordination complexes. (d) Peroxy acids expressed as principal groups are ranked, as a class, higher than all other acids. Previously, each such acid was placed just above the corresponding parent acid. Carbonic acid and related compounds are placed below those acids, e.g., carboxylic and sulfonic, expressed as functional suffixes, and above inorganic “oxo” acids. Derivatives of Arsonic and Boronic acids are named like those of other inorganic “oxo” acids with replaceable nuclear hydrogen atoms; thus, Benzenearsonic acid has become Arsonic acid, phenyl-. Derivatives of isocyanic acid and its chalcogen analogs are named substitutively by use of the prefixes isocyanato, isothiocyanato, etc. (e) Alcohols and phenols now rank as equal in precedence. (f) Ether, Sulfide, Selenide, and Telluride are no longer employed as heading parents and are therefore not listed in the Order of Precedence. Single chalcogen atoms are named substitutively (by use of oxy, thio, etc., radicals) or at organic replacement (“a”) names. (g) Phosphorus compounds without functional suffixes are ranked together (following nitrogen compounds). Formerly, phosphine oxide was placed above amines with phosphine and phosphorane following them. The same policy is adopted in descending order for nonfunctional heading parents derived from arsenic, antimony, bismuth, boron, silicon, germanium, tin, and lead. Then follow nonfunctional oxygen parents in the order: oxygen heterocycles, acyclic polyoxides (Trioxide, Peroxide), acyclic “oxa” names. Other chalcogens are ranked below oxygen in the order: sulfur, selenium, tellurium. Lowest in order of precedence are nonfunctional carbon skeletons. (h) In each class of nonfunctional compounds, ranked in the order of the most preferred heteroatom it contains, cyclic compounds are preferred over acyclic, and acyclic parents named by “a” nomenclature are less preferred than other acyclic parents of that hetero atom class. Among carbon compounds, similarly, carbocycles are preferred to acyclic carbon chains, regardless of length. Unsaturated skeletons are preferred to saturated skeletons with the same number and type of skeletal atoms; thus, Benzene is preferred to Cyclohexane (no policy change), and Pyridine is preferred to Piperidine (reversal of policy). 272. Organometallic compounds (¶ 194). Binary compounds of element hydrides, e.g., Arsorane, AsH5, Plumbane, PbH4, Germane, GeH4, are indexed at those headings. Thus, Lead chloride (PbCl4) became Plumbane, tetrachloro-. (In the carbon series, Carbon tetrachloride became Methane, tetrachloro-.) Amino derivatives of hydrides are now assigned “-amine” names, e.g., Germanediamine, and other functional suffixes are also employed, e.g., Bismuthinecarboxylic acid, but “-ol” to express a hetero-atomattached hydroxyl is used only with carbon and silicon. “A” names must (as usual) be employed when appropriate. 273. Oxo acids (¶ 219). Some changes (¶ 185) were made in 1972 to the content of the “Class I” list for esters of inorganic “oxo” acids. Pyrophosphoric acid, (HO)2P(O)OP(O)(OH)2, was renamed Diphosphoric acid. The new heading parent Diphosphonic acid was previously indexed at Phosphonic acid, anhydride. Since 1972, arsenic mononuclear acids have been treated analogously to phosphorus acids. Examples: Arsenic acid (H3AsO4) Arsonic acid Arsinic acid Arsenenic acid (HO)3AsO (HO)2HAsO (HO)H2AsO HOAsO2 Cyclic esters of arsenic and phosphorus acids are indexed at the ring names. Since the Tenth Collective Index period (1977-81), metal oxo acids (including oxo acids of antimony) and their salts have been indexed as coordination compounds or as mixed salts. The only exceptions are Chromic acid (H2CrO4), Chromic acid (H2Cr2O7), Manganic acid (H2MnO4) and Permanganic acid (HMnO4), which were retained as index heading parents. A few little-used nonmetallic oxo acid names, e.g., Mesosulfuric acid, were also discontinued. 274. Peptides (¶ 206), other than biologically active peptides with trivial names, containing two through twelve amino-acid residues are now indexed at the name of the C-terminal unit in every case; peptide amides are treated analogously. No change was made in the treatment of larger peptides. Some trivial acyl names were changed starting in the Twelfth Collective period (19871991). Thus α-aminobutyryl became 2-aminobutanoyl and lactoyl became 2hydroxypropanoyl. Cyclic peptides of two or three units are indexed at systematic ring-system names, larger compounds at “Cyclo” names such as Cyclo[Lalanyl-N5-acetyl-D-ornithylglycyl-L-alanyl-D-propyl-O-(1,1-dimethylethyl)-L-seryl] in which the units are cited in the order of occurrence, with preference given to the lowest alphabetic arrangement of parent amino-acid radicals. Prior to 1987 the term “Cyclic” was used instead of “Cyclo”. Additional entries are made at ring-system names. Peptides with fewer than four units and which contain disulfide linkages are now indexed, like larger peptides, at cysteine rather than cystine names. Linear depsipeptides are now usually indexed at the C-terminal amino-acid names; terminal hydroxy acids are expressed as carboxyalkyl esters. Cyclic depsipeptides are indexed at ring names or “Cyclo” names in analogy with peptides. Effective with Volume 129, the rules for naming peptites have been revised as follows: (1) In depsipeptide nomenclature, the chalcogen in a nonterminal hydroxy, mercapto, selenyl, or telluryl acid residue need no longer be α to the carbonyl. Any position is acceptable. (2) In ψ nomenclature (adopted in Volume 126 for certain pseudopeptides), glycine may now serve as one of the ψ residuesthe amino acids cited before and after the ψ term−−provided the other ψ residue is a standard chiral amino acid. In addition, a ψ residue may now be N-terminal, provided its CO is not replaced, or C-terminal, provided its NH is not replaced. Naturally-occurring biologically active peptides and depsipeptides of six to fifty units are indexed at the trivial names; those of five or fewer units are named like other peptides at the C-terminal amino acid or “Cyclo” name; trivially named stereoparents such as Bradykinin and Gramicidin S have continued to be employed for substances containing six through fifty units. Small species variations in trivially-named peptides are now interrelated by using one form as the reference compound; e.g., Fibrinopeptide B (orang-utan). See 115 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 283 Fibrinopeptide B (human), 10-L-leucine-12-glycine-; similar cross-references are now made between trivial names of closely-related peptides and corticotropin sequences; e.g., Kallidin. See Bradykinin, N2-L-lysyl-; α1,39-Corticotropin (human). See α1,39-Corticotropin (pig), 31-L-serine-. Esters of hydroxy and mercapto groups in amino-acid radicals of peptides are now expressed as substituents; e.g., O-acetyl-L-seryl. Functional derivatives of carboxy substituents are expressed by radicals which include the carboxyl group; e.g., N-[(phenylmethoxy)carbonyl]. Such former headings as Angiotensins were made singular in Volume 76. The indexing of Oxytocins and Vasopressins was further refined. Bovine insulin is now the reference compound for insulins, with the name Insulin (ox). Actinomycin D is the reference stereoparent to which other actinomycins are related for indexing purposes. Proteins (¶ 207) are indexed at trivial names, with accompanying species information. Synthetic peptides are indexed like polymers; the term “polymer with” is used instead of “peptide with” at amino-acid monomer names. 275. Peroxides (¶ 196). Binary headings were discontinued; Isopropyl peroxide became Peroxide, bis(1-methylethyl). The heading Peroxide is a nonfunctional oxygen compound; in the presence of more preferred compound classes, such radicals as (ethyldioxy) are employed. Hydroperoxide is a functional oxygen compound ranking just above amines; such names as Peroxyacetyl hypochlorite are replaced by Peroxide, acetyl chloro, etc. 276. Phosphorus compounds (¶¶ 197, 219). Functional suffixes are now employed with phosphorus hydride names; e.g., Phosphinecarboxylic acid (formerly Formic acid, phosphino-) and Phosphoranamine (formerly Phosphorane, amino-). The phosphoro radical, −P=P−, was renamed 1,2-diphosphenediyl; phosphino was retained, but diphosphino, H2P−PH−, was renamed diphosphinyl, and diphosphinetetrayl became 1,2-diphosphinediylidene. Phosphorothioic and Phosphorodithioic acids were added to Phosphoric and Phosphorous acids in “Class I” (¶ 185) for the indexing of esters. Pyrophosphoric acid was renamed Diphosphoric acid. Diphosphonic acid became the new name for Phosphonic acid, anhydride. Phosphonium ylides are indexed only as ylidene derivatives of Phosphorane (¶ 201). Prior to the Twelfth Collective period an additional Chemical Substance and Formula Index entry appeared for the phosphonium ylide name. The phosphoryl radical was eliminated for non-acid mononuclear analogs of phosphoric acid in Volume 120; thus phosphoryl chloride (POCl3) is now phosphoric trichloride. 277. Polymers (¶ 222). Prior to the Fifteenth Collective period, polymers with known component monomers were indexed at the name of each monomer as actually reported in the original document. Polymers are now indexed at the preferred name only. The preferred name appears in the Formula Index at the molecular formula of each monomer used in the polymer. Names based on structural repeating units (SRUs) have continued to be used as additional index names for polymers of well characterized or assumed structure. In the cases of very common trade-named industrial polymers of known composition for which cross-references are used, the SRU name is preferred. Thus, 1,4-Benzenedicarboxylic acid, polymers, polymer with 1,2-ethanediol. See Poly(oxy1,2-ethanediyloxycarbonyl-1,4-phenylenecarbonyl); Nylon 6. See Poly[imino(1-oxo-1,6-hexane-diyl)]. At monomer names, the terms “polymers,” “polyamides,” “polyesters,” etc., were replaced by “homopolymer” except for general studies; “polymer with” was retained for copolymers named at monomer headings and replaced such terms as “polyamide with”, “polyester with”, etc.; “copolymers” is an acceptable general term. Block, graft, and alternating copolymers are registered and indexed with their own specific Registry numbers starting in the Twelfth Collective period (1987-1991). The terms “block”, “graft” and “alternating” are part of the index name for these kinds of polymers. Starting with Volume 145 (June 2006), diblock, triblock, tetrablock and pentablock polymers are indexed with their own specific Registry numbers. The terms diblock, triblock, tetrablock and pentablock are part of the index names for these polymers. Siloxanes prepared by hydrolytic polymerization of chlorosilanes are now, starting in 1994, registered and indexed at the monomer names with the term “hydrolytic” cited in the modification, along with the term “homopolymer” or “polymer with”. Cyclic acetals of ethenol homopolymer and ethenyl acetate-ethenol copolymer are indexed with their own specific Registry number starting with the Sixteenth Collective period. (December 2006). The names include the phrase “cyclic acetal with” followed by a specific aldehyde name in the modification. Phenol condensation products are now indexed at Phenol polymers, with “polymer with formaldehyde” or other appropriate term cited in the modification. Urea condensation products are named analogously at Urea polymers. 278. Porphyrins and Bile pigments (¶ 223) were affected by the new rule that indicated hydrogen of ring systems is always cited. 21H,23H-Porphine and 21H,23H-Porphyrazine are the forms preferred for these and related substances unless an original document emphasizes the absence of hydrogen at these positions. The 29H,31H-form of Phthalocyanine is preferred; the heading 21HBiline is employed unless hydrogen is absent from that position, in which case 22H-Biline is indexed. (An (all-Z) form is now assumed for Biline.) Radicals. See Substituent prefixes (¶ 287). 279. Replacement (“a”) nomenclature (¶ 127), in which replacement of carbon by heteroatoms is indicated by terms such as “aza,” “oxa,” and “thia,” was unchanged for cyclic skeletons, but was amended for acyclic compounds, primarily to eliminate exceptions for certain classes, including silicon compounds. Now, “a” names are used whenever four or more “hetero units” (isolated hetero atoms, homogeneous hetero chains, or groups for which simple radical names are employed, such as disiloxanediyl) are present, so long as the resulting name, including functional suffixes, does not express a lower functionality than the alternative conventional name. The hetero atoms must not be in an abnormal valency state (unless this valency can be readily expressed), and the “a”-named chain must not be terminated by a nitrogen or chalcogen atom. (“A” names are not used for peptides, polymers or purely inorganic chains.) 280. Replacement nomenclature for functions (¶ 129) was extended to various classes of acids and acid derivatives, as outlined by the following examples (former names are in parentheses): Ethanethioic acid Ethane(dithioic) acid Ethaneperoxoic acid Butanebis(thioic) acid Carbonothioic acid Carbamodithioic acid Methanimidamide Imidodicarbonic acid Diimidotricarbonimidic diamide 1,3-Benzenedisulfonothioic acid (Acetic acid, thio-) (Acetic acid, dithio-) (Peroxyacetic acid) (Succinic acid, 1,4-dithio-) (Carbonic acid, thio-) (Carbamic acid, dithio-) (Formamidine) (Imidodicarboxylic acid) (Triguanide) (m-Benzenedisulfonic acid, 1,3-dithio-) 281. Ring systems (¶¶ 145-157). Fused oxireno and thiireno derivatives of hydrocarbon rings are now indexed according to the general rule that the base component should be a heterocycle; thus, Naphthalene, 2,3-epoxy- has become Naphth[2,3-b]oxirene. Adamantane and its replacement derivatives are indexed at Tricyclo[,7]decane, 2-Thiatricyclo[,7] decane, etc. (¶ 155). The locants o-, m-, p-, and ν- in ring names were replaced by numerals; as- and s- are used only with Indacene and its fused derivatives; thus, mDioxane became 1,3-Dioxane; p-Terphenyl became 1,1′:4′,1′′-Terphenyl; sTriazine became 1,3,5-Triazine; and Benz[e]-as-indacene is unchanged. Some trivial names were replaced; thus, Quinuclidine was renamed 1-Azabicyclo[2.2.2]octane. Radical names from these ring systems were changed correspondingly. Special names for partially hydrogenated ring systems, e.g., Acridan, Indan, Indoline, Phthalan, Pyrroline, were abandoned; thus Indan became 1H-Indene, 2,3-dihydro-. Norbornane, Norcarane, and Norpinane are now indexed at the systematic “Bicyclo-” names. Ring systems containing metals other than antimony, tin, lead, germanium, or bismuth are now indexed by coordination nomenclature. In ring-assembly names, points of attachment are now cited, except for twocomponent assemblies of cycloalkenes. Thus, 1,1′-Biphenyl, 1,2′-Binaphthalene (formerly 1,2′-Binaphthyl), Bi-2-cyclohexen-1-yl. Ring assemblies in which component rings are joined by double bonds are now indexed at a component name, e.g., Cyclopentane, cyclopentylidene- (formerly Bicyclopentylidene). The Hantzsch-Widman system (¶ 146) was extended, beginning in 1987, to partially or fully saturated rings, formerly named by organic replacement nomenclature, e.g. Stannolane (formerly Stannacyclopentane). Prior to Volume 121 the rings 1,2,5-Oxadiazole and 2,1,3-Benzoxadiazole were named Furazan and Benzofurazan, respectively. Non-standard valence states (¶ 158) of certain ring heteroatoms were denoted by the greek letter lambda (λ) starting in 1987, e.g. 1λ4,3λ4,5λ4,7λ41,3,5,7,2,4,6,8-Tetrathiatetrazocine (formerly 1H,3H,5H,7H-1,3,5,7,2,4,6,8Tetrathiatetrazocine). Names for cyclic systems containing ring heteroatoms in non-standard valence states described by the “hydro” prefix (¶ 158) were changed beginning in 1987 to allow the expression of principal suffixes and radicals, e.g. 2H-1,4Selenazin-2-one, 1,1-dihydro-1,1-dimethyl-(formerly 2H-1,4-Selenazine, 1,1-dihydro-1,1-dimethyl-2-oxo-). 281A. Salts (¶ 198). Beginning with the Twelfth Collective Index, salts of substitutive cations no longer have additional index entries at the following common anions: Acetic acid, 2,2,2-trifluoro-, ion(1-); Borate(1-), tetrafluoro-; Borate(1-), tetraphenyl-; Methanesulfonic acid, 1,1,1-trifluoro-, ion(1-); Phenol, 2,4,6-trinitro-, ion(1-); Phosphate(1-), hexafluoro-; Sulfuric acid, monoethyl ester, ion(1-). 282. Silicon compounds (¶ 199). Former binary names for silicon halides are now indexed at Silane; for example, Silicon chloride (SiCl4), is now indexed at Silane, tetrachloro-. Functional suffixes are now appended to Silane, Disilane, Disiloxane, etc., but conjunctive names are not formed from them. Silanol and Silanediol now rank above all carbon-skeleton monohydric and dihydric alcohols, respectively, by reason of their hetero atom content (¶ 106). Similarly, Silanamine ranks above Benzenamine, etc. Silthianes are now spelled out as silathianes; 1,3-disiloxanediyl, 1,5-trisilathianediyl, 1,7-tetrasilazanediyl, etc., all rank as single hetero units (¶ 127) in the formation of “a” names. A total of four such units (of any kind) are now necessary for a compound to be named by replacement nomenclature. Silicic acids now all belong to “Class II” in the naming of esters (¶ 185). Since the Tenth Collective Index period, the Silicic acid heading has been generally restricted to mono- and dinuclear oxo acids of silicon. 283. Spelling (¶ 107). Elided forms of radicals were largely discontinued. Nitramino became (nitroamino); acetoxy became (acetyloxy); naphthyl became naphthalenyl. Ethoxy, methoxy, propoxy, butoxy, phenoxy, and thienyl were retained, but branched-chain radicals are now named as derivatives of the straight-chain alkoxy parents; thus, isopropoxy became (1-methylethoxy). Elided forms of heading parents (Pyridol; Pyridone) are now spelled out (Pyridinol; Pyridinone). Punctuation in compound names is unchanged. ¶ 284 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 116 284. Stereochemistry (¶ 203). Major revisions were made in this area for the Ninth Collective Index Period (1972-76). The concept of stereoparents (¶ 285) was introduced for those substances, mainly natural products, containing complex stereochemistry and not readily indexed at systematic names. For other substances, the stereochemistry is expressed in the name by use of relative and absolute descriptors, including cis- and trans-; endo- and exo-; αand β-; E- and Z-; R- and S-; and R*- and S*-. The Sequence Rule of Cahn, Ingold, and Prelog is applied in the assignment of these descriptors. A special system was developed for coordination compounds (¶ 203 III). Beginning with Volume 120, the sign of optical rotation (+), (-), or (±)- is assigned to substances with visual wavelengths other than the sodium-D line. Beginning with Volume 126 (1997), in order to provide more accurate descriptions of and improved access to substances whose stereochemistry has not been completely defined, CAS now registers and names substances with partially defined stereochemistry. Previously, partial stereochemistry was generally ignored. The presence of unknown chiral centers is indicated by the addition of ther term “[partial]-” to the end of the normal stereochemical descriptor. When the reference ring or chain has incompletely defined chiral atoms/bonds, the format cites the stereo using R and S terms with their nomenclature locants for all known centers. If this method is used to describe a substance for which only relative stereochemistry is known, “rel” is added to the stereochemical descriptor. Racemic mixtures of substances with single chiral centers are now indexed, registered, and named as non-stereospecific substances. Racemates having more than one chiral center are indexed, registered, and named as having only relative stereochemistry. Stereochemical descriptors were simplified beginning with Volume 129. The need for a single expression to describe the total stereochemistry of a molecule has been eliminated. Stereochemical terms are now placed within the parts of a chemical name to which the stereochemical information applies. Only the stereochemistry contained in the heading parent is expressed in the name modification following all other structural information. The use of the term “[partial]” has been discontinued. The terms R and S are employed for chiral elements possessing either absolute or relative stereochemistry. The term rel is used in conjunction with R and S for structures with only relative stereochemistry. E and Z are used primarily to describe geometrical isomerism about double bonds. The relative terms cis, trans, endo, exo, syn, anti, α, and β are used as alternatives to R and S in certain limited situations. 285. Stereoparents (¶ 202) are heading parents whose names imply stereochemistry, as indicated by structural diagrams shown at these names in the Chemical Substance Index. Synonyms and cross-references for the systematic names are always provided. The stereochemistry implied by the stereoparent, and shown in the diagram, may be augmented or selectively reversed in the name. Stereoparents include biologically significant amino acids, carbohydrates, and cyclic natural products (alkaloids, steroids, terpenes) within certain limitations. Stereoparents are preferred to systematically named substances of higher functionality in the naming of esters, mixtures, molecular addition compounds, and polymers. Derivatives of stereoparents are kept at the stereoparent names as much as practicable, but substituents (¶ 287) are named systematically in accordance with the changes in general index nomenclature. Beginning with Volume 126 (1997), infrequently used terpene, steroid, alkaloid, and antibiotic stereoparent terms have been replaced by systematic names. For example, Nemuarine and 15-Thialanostane are no longer used in index names. Frequently occurring stereoparents, such as Pregnane, Cholane, Cholestane, 9, 10-Secocholestane, Morphinan, Retinoic acid, and Erythromycin are maintained. Cross-references from the previously used stereoparent names will guide users to the corresponding systematic index names. Amino acid sequence names are now assigned to most systematically named linear peptides. In an amino acid sequence name, the C-terminal residue is the index heading parent, and the other residues are cited in the substituent, beginning with N-terminal residue and continuing from left to right in the sequence; e.g., L-Lysine, D-alanylglycyl-L-leucyl-. Psi (ψ) nomenclature is now used to describe certain modifications of the peptide bond. The Greek letter ψ conveys the fact that a peptide bond has been replaced by a pseudopeptide bond. In an amino acid sequence name, the format of the ψ term is ...-A-ψ(X-X’)-B-..., where A is the amino acyl radical whose carbonyl group has been modified to X and B the amino acyl radical whose α-amino group has been modified to X’. X and X’ are shown as strings of element symbols, separated by a bond; e. g., ...-L-valyl-ψ(CH2-NH)-L-tyrosyl-. 286. Steroids (¶ 211). Stereochemical descriptors, e.g., “5α-,” which formerly appeared as a prefix at steroid names, were combined in Volume 76 with descriptors required for suffixes and substituent prefixes and are now cited in parentheses in their own field. Cyclogonanes were discontinued as the names of ring systems. Cyclogonane stereoparents are retained, with stereochemistry defined by illustrative diagrams in the Chemical Substance Index. Trivial names for steroids, including Cholesterol, Ergocalciferol, and Testosterone, were discontinued as heading parents. Use of “homo” (to denote ring enlargement), “nor” (to denote ring contraction), and “seco” (to denote ring fission), are now further restricted. Functional derivatives of steroids are indexed at the steroid names, either in the substituents (for derivatives of subsidiary functions) or in the modifications (for derivatives of the principal functions). Acyclic acetals are expressed by alkyloxy or aryloxy substituents (¶ 196); cyclic acetals with formaldehyde by methylenebis(oxy) radicals; other cyclic acetals by a modification phrase such as “cyclic 1,2-ethanediyl acetal” (if a principal group has been acetalized) or by an alkanediylbis(oxy) or alkylidenebis(oxy) substituent. Steroidal lactones are “opened” to permit the steroid stereoparent to be used; the lactone is then cited in the modification. 287. Substituent prefixes (radicals) (¶¶ 132, 161). Groups always expressed as substituents now include isocyano, isocyanato, isothiocyanato, etc., and groups terminating in oxy, thio, sulfinyl, sulfonyl, and their analogs, such as seleno and telluronyl. Changes in radical names include iodosyl (instead of iodoso) for −IO; and iodyl (instead of iodoxy) for −IO2. Morpholino was changed in Volume 76 to 4-morpholinyl; piperidino to 1-piperidinyl; the unsubstituted diazeno radical, HN=N−, to diazenyl; p-phenylene, etc., to 1,4-phenylene, etc.; ν-phenenyl to 1,2,3-benzenetriyl; benzyl to (phenylmethyl); styryl to (2-phenylethenyl); ptolyl to (4-methylphenyl); 2,4-xylyl to (2,4-dimethylphenyl); and similarly for other radicals containing a benzene ring and one or more acyclic chains. Thenyl became (thienylmethyl) and furfuryl became (2-furanylmethyl). Ring-assembly radicals are now based on the ring assembly names, as, [1,2′-binaphthalen]-8′-yl and [1,1′-biphenyl]-4,4′-diyl (¶ 161). Acyl radicals in substitutive names were replaced by substituted radicals (exceptions are acetyl, benzoyl, carbonyl, and, when unsubstituted, formyl). Hence propionyl became (1-oxopropyl); acetimidoyl became (1-iminoethyl); succinoyl became (1,4-dioxo-1,4-butanediyl). The three radicals carbonimidoyl, −C(:NH)−; carbonohydrazonoyl, −C(:NNH2)−, and carbonothioyl, − C(:S)− were introduced for use in multiplicative nomenclature and for cases in which both free valencies are attached to the same atom. In other cases, (iminomethyl) (formerly formimidoyl), (thioxomethyl), etc., are employed. Replacement (“a”) names for acyclic radicals (¶ 128) were introduced under the same restrictions as for heading parents. The free valencies, not the hetero atoms, are preferred for lowest locants, which are always cited; e.g., 4,12-dioxa-7,9-dithiatetradec-1-yl. Compound and complex radicals are now constructed in accordance with revised rules which reflect the new policies for compounds. The most important changes were emphasis on hetero-atom content of the parent radical, abandonment of “like treatment of like things” and the “complexity” principle, elimination of preference for unsaturated acyclic radicals regardless of size, consistent application of the principle of “lowest locants” for substituents on the parent radical, and adoption of more systematic radical names. A list of substituent prefixes (radicals) as revised for the Ninth Collective Index Period (1972-1976) constitutes Section H (¶ 294). 288. Sulfur compounds (¶ 200). Sulfide was discontinued as a heading parent in Volume 76, as were such binary headings as Phenyl sulfide. Compounds containing one or more single sulfur atoms are now indexed substitutively by use of thio radicals or at “thia”-named index parents (¶ 127). Thus, Sulfide, ethyl phenyl, became Benzene, (ethylthio)-, and Propyl sulfide is now indexed at Propane, 1,1′-thiobis-. The retained headings Disulfide, Trisulfide, etc., rank as nonfunctional acyclic sulfur parents, below oxygen compounds and above selenium compounds. Within the class, a partial descending order is: heterocyclic sulfur compounds, e.g., Thiophene; “a”-named acyclic hetero systems, e.g., 2,6,9,12,13-Pentathiapentadecane; acyclic trisulfide, disulfone, disulfoxide, disulfide. 1,2-Episulfides are named as Thiirane or Thiirene derivatives; 1,3-episulfides as Thietane or Thiete derivatives. Acyclic mercaptals and mercaptoles are now named like sulfides by use of thio radicals. Selenium and tellurium compounds are treated in strict analogy with sulfur compounds. 289. Sulfones and Sulfoxides (¶ 200). Sulfone was discontinued as a heading parent, as were binary sulfone headings like Isopropyl sulfone, now indexed at Propane, 2,2′-sulfonylbis-. Sulfonyl radicals are used for all compounds containing single SO2 groups, e.g., Butane, 1-chloro-3-(methylsulfonyl)- (formerly Sulfone, 3-chloro-1-methylpropyl methyl). Disulfone, Trisulfone, etc., are retained. Sulfoxides are indexed in an analogous manner by use of sulfinyl radicals. Acyclic skeletons containing four or more sulfur units may be indexed at “thia”- names with oxide terms in the index modification. Cyclic sulfones and sulfoxides are indexed at ring names; e.g., Thiirane, 1,1-dioxide (formerly Ethylene sulfone). 289A. Tautomers (¶ 122). To avoid scattering of information in the index, CA, aided by new machine programs, now indexes certain common tautomeric systems at single preferred index names, regardless of the particular structures presented in original documents. The most common tautomers handled in this way include compounds containing the nitrogenous skeletons N-N-N, N-C-N, N-C-O, and N-C-S, as well as certain phosphorus and sulfur acids and amides. In general, the preferred index name expresses the tautomeric form in which a double bond extends to an oxygen atom, rather than to a sulfur or nitrogen; after this condition has been satisfied, the preferred name usually expresses the maximum number of highest functions. 290. Terpenes (¶ 212) are now named at stereoparent names (¶ 285) only when they contain four or more rings or possess complex stereochemistry. Hence, many trivial names formerly employed as index headings are now cross-referred to systematic names; e.g., Eudesmane. See Naphthalene, decahydro-1,4a-dimethyl-7-(1-methylethyl)-, (1R,4aR,7R,8aS)-. Illustrative diagrams for terpene stereoparents, e.g., Gammacerane, Lanostane, showing the stereochemistry for each, are provided in the Chemical Substance Index. New stereoparents, formed by ring enlargement, contraction, scission, or addition, are adopted as they are needed. When ring scission results in a structure which does not qualify for a terpene stereoparent name, systematic nomenclature is used. Cyclic acetals of terpenes are expressed at stereoparent names, either in the modification or by use of appropriate substituents, in analogy with steroids (¶ 286). Lactones are expressed in the modification at terpene acid headings. 117 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 293A 291. Thiols (¶ 175) have been affected only by the general changes in indexing policy (¶ 255), including those for conjunctive names, abandonment of trivial names, and discontinuance of like treatment of like things. Thus, α-Toluenethiol became Benzenemethanethiol; p-Cymene-2-thiol became Benzenethiol, 2-methyl-5-(1-methylethyl)-; and Ethanethiol, 1,2-diphenyl-, became Benzeneethanethiol, α-phenyl-. 292. Urea (¶ 183) was retained as a heading parent; Urea, thio-, and its derivatives are now indexed at Thiourea. In both cases, the locants 1- and 3- were replaced by N- and N′-. Urea ranks as an amide of Carbonic acid, which is now placed below the “organic” acids, including carboxylic and sulfonic acids. Acyclic acyl ureas are therefore indexed at “organic” amide names. Pseudourea was renamed Carbamimidic acid. In the following list, former names are shown in parentheses: Urea, N ′ -ethyl-N,N-dimethylAcetamide, N-(amino carbonyl)Ethanethioamide, N-(ami nocarbonyl)Urea, N-(aminoiminomethyl)1,2-Hydrazinedicarboxamide Imidodicarbonic diamide Urea, N,N ′ -diphenylDiimidotricarbonic diamide Carbamimidothioic acid, N-methyl-, ethyl ester (Urea, 3-ethyl-1,1-dimethyl-) (Urea, acetyl-) (Urea, (thioacetyl)-) (Urea, amidino-) (Biurea) (Biuret) (Carbanilide) (Triuret) (Pseudourea, 2-ethyl-3-methyl-2thio-) 293. Vitamins (¶ 224). Index headings such as Vitamin B, Vitamin F, are used for general discussions of vitamin activity and for ill-defined substances named by authors. Otherwise, many specific vitamin names have been crossreferred to more systematic names. The stereoparent Retinol is used for Vitamin A1 (Vitamin A2 is indexed at Retinol, 3,4-didehydro-); Riboflavine (Riboflavin beginning in Volume 86) for Vitamin B2; and L-Ascorbic acid for Vitamin C. Vitamin B12 is the only specific vitamin name retained as a heading parent; related compounds have continued to be indexed at names such as Cobinamide and Cobyrinic acid. 293A. Zwitterionic compounds (¶¶ 201, 224). Prior to Volume 119 the expression “hydroxide, inner salt” was used in the modification of names of zwitterionic compounds at “-ium” headings. “Hydroxide” was used as the salt phrase in the modification. Conceptually, a molecule of water (comprised of the hydroxide anion and a hydrogen atom attached to a hetero atom) was “removed” by the use of the phrase “inner salt”. The term “inner salt” now indicates an unspecified compensating anion located in the same molecule as the cation. The assumed “hydroxide” anion is no longer expressed. Beginning with Volume 121 meso-ionic Sydnone and Sydnone imine derivatives (¶ 201) are structured and named systematically as inner salts of 5Hydroxy-3-substituted-1,2,3-oxadiazolium and 5-Amino-3-substituted1,2,3-oxadiazolium, respectively. Hydrohalide salts of sydnone imines are structured and named as onium halides. ¶ 294 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 H. ILLUSTRATIVE LIST OF SUBSTITUENT PREFIXES 118 294. (The equals (=) directs the user from the boldface name to the current CA name; absence of the sign indicates that the boldface name is correct.) abietamido = [[[1,2,3,4,4a,4b,5,6,10,10a-decahydro-1,4a-dimethyl-7-(1-methylethyl)-1-phenathrenyl]carbonyl]amino] C19H29CONH− acenaphthenyl = (1,2-dihydroacenaphthylenyl) (C12H9)− 1,2-acenaphthenylene = (1,2-dihydro-1,2acenaphthylenediyl) −(C12H8)− 1-acenaphthenylidene = 1(2H)-acenaphthylenylidene (C12H8)= acetamido = (acetylamino) AcNH− acetenyl = ethynyl HC≡C− acetimido = (acetylimino) or (1-iminoethyl) AcN= or MeC(=NH)− acetimidoyl = (1-iminoethyl) MeC(=NH)− acetoacetamido = [(1,3-dioxobutyl)amino] MeCOCH2CONH− acetoacetyl = (1,3-dioxobutyl) MeCOCH2CO− acetohydroximoyl = [1-(hydroxyimino)ethyl] MeC(=NOH)− acetonyl = (2-oxopropyl) MeCOCH2− acetonylidene = (2-oxopropylidene) MeCOCH= acetoxy = (acetyloxy) AcO− acetyl Ac (MeCO−) acetylene = 1,2-ethanediylidene =CHCH= acridanyl = (9,10-dihydroacridinyl) (C13H10N)− acryloyl = (1-oxo-2-propen-1-yl) H2C=CHCO− acrylyl = (1-oxo-2-propen-1-yl) H2C=CHCO− adamantyl = tricyclo[,7]decyl (C10H15)− adamantylene = tricyclo[,7]decanediyl −(C10H14)− adipaldehydoyl = (1,6-dioxohexyl) HCO(CH2)4CO− adipamoyl = (6-amino-1,6-dioxohexyl) H2NCO(CH2)4CO− adipaniloyl = [1,6-dioxo-6-(phenylamino)hexyl] PhNHCO(CH2)4CO− adipoyl = (1,6-dioxo-1,6-hexanediyl) −CO(CH2)4CO− adipyl = (1,6-dioxo-1,6-hexanediyl) −CO(CH2)4CO− alaninamido = [(2-amino-1-oxopropyl)amino] MeCH(NH2)CONH− alanyl1 = (2-amino-1-oxopropyl) MeCH(NH2)CO− β-alanyl1 = (3-amino-1-oxopropyl) H2N(CH2)2CO− aldo2 = oxo O= alloisoleucyl1 = (2-amino-3-methyl-1-oxopentyl) EtCHMeCH(NH2)CO− allophanamido = [[[(aminocarbonyl)amino]carbonyl]amino] H2N(CONH)2− allophanoyl = [[(aminocarbonyl)amino]carbonyl] H2NCONHCO− allothreonyl1 = (2-amino-3-hydroxy-1-oxobutyl) MeCH(OH)CH(NH2)CO− allyl = 2-propen-1-yl H2C=CHCH2− β-allyl = (1-methylethenyl) H2C=CMe− π-allyl = (η3-2-propen-1-yl) [ C H 2 - - - C H - - - CH 2 ] − allylidene = 2-propen-1-ylidene H2C=CHCH= ambrosan-6-yl = [decahydro-3a,8-dimethyl-5-(1methylethyl)-4-azulenyl] (C15H27)− amidino = (aminoiminomethyl) H2NC(=NH)− amidoxalyl = (2-amino-2-oxoacetyl) H2NCOCO− amino H2N− (aminoamidino) = (hydrazinyliminomethyl) H2NNHC(=NH)− (aminoiminophosphoranyl) = (P-aminophosphinimyl) H2NPH(=NH)− ammonio H3N+− amoxy = (pentyloxy) Me(CH2)4O− amyl = pentyl Me(CH2)4− tert-amyl = (1,1-dimethylpropyl) EtCMe2− amylidene = pentylidene BuCH= anilino = (phenylamino) PhNH− anisal = [(methoxypheny])methylene] MeOC6H4CH= anisidino = [(methoxyphenyl)amino] MeOC6H4NH− anisoyl = (methoxybenzoyl) MeOC6H4CO− anisyl = (methoxyphenyl) or [(methoxyphenyl)methyl] MeOC6H4− or MeOC6H4CH2− anisylidene = [(methoxyphenyl)methylene] MeOC6H4CH= anthranilamido = [(2-aminobenzoyl)amino] 2−H2NC6H4CONH− anthraniloyl = (2-aminobenzoyl) 2−H2NC6H4CO− anthranoyl = (2-aminobenzoyl) 2−H2NC6H4CO− anthraquinonyl = (9,10-dihydro-9,10-dioxoanthracenyl) (C14H7O2)− anthraquinonylene = (9,10-dihydro-9,10dioxoanthracenediyl) −(C14H6O2)− anthroyl = (anthracenylcarbonyl) (C14H9)CO− anthryl = anthracenyl (C14H9)− anthrylene = anthracenediyl −(C14H8)− antimono = 1,2-distibenediyl −Sb=Sb− antipyrinyl (antipyryl) = (2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl) O Ph N MeN 1 5 2 −CO(CH2)7CO− azelaaldehydoyl = (1,9-dioxononyl) HCO(CH2)7CO− azi5 (see also azo) −N=N = 3H-diazirine (component ring in a spiro name) azido N3− (azidoformyl) = (azidocarbonyl) N3CO− azino =NN= = 1,2-hydrazinediylideneazo (see also azi) −N=N− = diazenyl or 1,2-diazenediyl azoxy −N(O)=N− = (2-oxidodiazenyl)- or (1-oxido-1,2-diazenediyl) benzal = (phenylmethylene) PhCH= benzamido = (benzoylamino) BzNH− benzenesulfenamido = [(phenylthio)amino] PhSNH− benzenesulfonamido = [(phenylsulfonyl)amino] PhSO2NH− benzenetriyl C6H3 ≡ benzenyl = (phenylmethylidyne) PhC ≡ benzhydryl = (diphenylmethyl) Ph2CH− benzhydrylidene = (diphenylmethylene) Ph2C= benzidino = [(4′-amino[1,1′-biphenyl]-4-yl)amino] 4−(4−H2NC6H4)C6H4NH− benziloyl = (2-hydroxy-2,2-diphenylacetyl) Ph2C(OH)CO− benzimidazolinyl = (2,3-dihydro-1H-benzimidazolyl) (C7H7N2)− 2-benzimidazolyl = 1H-benzimidazol-2-yl (C7H5N2)− benzimido = (benzoylimino) or (iminophenylmethyl) BzN= or PhC(=NH)− benzimidoyl = (iminophenylmethyl) PhC(=NH)− benzofuryl = benzofuranyl (C8H5O)− benzohydroximoyl = [(hydroxyimino)phenylmethyl] PhC(=NOH)− o-benzoquinon-3-yl = (5,6-dioxo-1,3-cyclohexadien-1-yl) (C6H3O2)− p-benzoquinon-2,5-ylene = (3,6-dioxo-1,4-cyclohexadiene-1,4-diyl) −(C6H2O2)− benzoselenophene-yl C8H5Se− benzoxy = (benzoyloxy) BzO− benzoyl Bz (PhCO−) (benzoylacetyl) = (1,3-dioxo-3-phenylpropyl) PhCOCH2CO− (benzoylformyl) = (2-oxo-2-phenylacetyl) PhCOCO− benzyl = (phenylmethyl) PhCH2− benzylidene = (phenylmethylene) PhCH= benzylidyne = (phenylmethylidyne) PhC ≡ (benzyloxy) = (phenylmethoxy) PhCH2O− (benzylselenyl) = [(phenylmethyl)seleno] PhCH2Se− bicarbamoyl = (1,2-hydrazinediyldicarbonyl) −CONHNHCO− bicyclo[1.1.0]butylene = bicyclo[1.1.0]butanediyl −(C4H4)− biphenylyl = [1,1′-biphenyl]yl PhC6H4− biphenylene = [1,1′-biphenyl]diyl −(C12H8)− biphenylylene = [1,1′-biphenyl]diyl −(C12H8)− bismuthino BiH2− bismuthylene BiH= bismuthylidyne Bi≡ [2,2′-bithiophen]-5-yl C8H5S2− 2-bornyl = (1,7,7-trimethylbicyclo[2.2.1]hept-2yl) (C10H17)− 3-bornylidene = (4,7,7-trimethylbicyclo[2.2.1]hept-2-ylidene) (C10H16)= 4 (HO) B− borono 2 boryl BH2− borylene BH= borylidyne B≡ bromo Br− 1,3-butadienediylidene = 1,3-butadiene-1,4diylidene =C=CHCH=C= butadiynylene = 1,3-butadiyne-1,4-diyl −C≡ CC≡C− 2-butenylene = 2-butene-1,4-diyl −CH2CH=CHCH2− butoxy BuO− sec-butoxy = (1-methylpropoxy) EtCHMeO− tert-butoxy = (1,1-dimethylethoxy) Me3CO Me antipyroyl = [(2,3-dihydro-1,5-dimethyl-3-oxo-2phenyl-1H-pyrazol-4-yl)carbonyl] O Ph N MeN 1 5 2 CO — Me apocamphanyl = (7,7-dimethylbicyclo[2.2.1]heptyl) (C9H15)− apotrichothecanyl = (decahydro-3a,6,8a,8b-tetramethyl-1H-cyclopenta[b]benzofuranyl) (C15H25O)− arginyl1 = [2-amino-5-[(aminoiminomethyl)amino]-1-oxopentyl] H2NC(=NH)NH(CH2)3CH(NH2)CO− arseno = 1,2-diarsenediyl −As=As− arsenoso OAs− arsinico3,4 HOAs(O)= arsinidenio H2As+= arsinimyl AsH2(=NH)− arsino AsH2− arsinothioyl AsH2(S)− arsinyl AsH2(O)− arsinylidene AsH(O)= arso O2As− arsonio H3As+− arsono4 (HO)2As(O)− arsononitridyl AsH(≡N)− arsoranyl AsH4− arsoranylidene H3As= arsoranylidyne AsH2≡ arsylene = arsinidene AsH= arsylidyne = arsinidyne As≡ asaryl = (2,4,5-trimethoxyphenyl) 2,4,5−(MeO)3C6H2− asparaginyl1 = (2,4-diamino-1,4-dioxobutyl) H2NCOCH2CH(NH2)CO− α-asparaginyl1 = (3,4-diamino-1,4-dioxobutyl) H2NCOCH(NH2)CH2CO− asparagyl = asparaginyl aspartoyl1 = (2-amino-1,4-dioxo-1,4-butanediyl) −COCH2CH(NH2)CO− aspartyl = aspartoyl or unspecified aspartyl (see below) α-aspartyl1 = (2-amino-3-carboxy-1-oxopropyl) HO2CCH2CH(NH2)CO− β-aspartyl1 = (3-amino-3-carboxy-1-oxopropyl) HO2CCH(NH2)CH2CO− astato At− astatoxy = astatyl O2At− atisanyl (from atisane) (C20H33)− atropoyl = (1-oxo-2-phenyl-2-propen-1-yl) H2C=CPhCO− azelaoyl = (1,9-dioxo-1,9-nonanediyl) 119 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 carvacryl = [2-methyl-5-(1-methylethyl)phenyl] Me2CH 6 1 ¶ 294 butyl Bu (Me(CH2)3−) butylβ = (2-methylpropyl) Me2CHCH2− butylγ = (1,1-dimethylethyl) Me3C− sec-butyl = (1-methylpropyl) EtCHMe− tert-butyl = (1,1-dimethylethyl) Me3C− 1,4-butylene = 1,4-butanediyl −(CH2)4− sec-butylidene = (1-methylpropylidene) EtCMe= (butyloxy) = butoxy BuO− butynedioyl = (1,4-dioxo-2-butyne-1,4-diyl) −COC ≡ CCO − butyryl = (1-oxobutyl) PrCO− cacodyl = (dimethylarsino) Me2As− cadinan-1-yl = [octahydro-4,7-dimethyl-1-(1methylethyl)-4a(2H)-naphthalenyl] (C15H29)− 2-camphanyl = (4,7,7-trimethylbicyclo[2.2.1]hept2-yl) (C10H17)− camphoroyl (from camphoric acid) = [(1,2,2-trimethyl-1,3-cyclopentanediyl)dicarbonyl] −CO(C8H14)CO− 5-camphoryl (from camphor) = (4,7,7-trimethyl-5oxobicyclo[2.2.1]hept-2-yl) (C10H15O)− canavanyl = [O-[(aminoiminomethyl)amino]homoseryl]1 or [2-amino-4-[[(aminoiminomethyl)amino]oxy]-1-oxobutyl] H2NC(=NH)NHO(CH2)2CH(NH2)CO− caprinoyl = (1-oxodecyl) Me(CH2)8CO− caproyl (from caproic acid) = (1-oxohexyl) Me(CH2)4CO− capryl (from capric acid) = (1-oxodecyl) Me(CH2)8CO− capryloyl (from caprylic acid) = (1-oxooctyl) Me(CH2)6CO− caprylyl (from caprylic acid) = (1-oxooctyl) Me(CH2)6CO− carbamido = [(aminocarbonyl)amino] H2NCONH− carbamoyl = (aminocarbonyl) H2NCO− carbamyl = (aminocarbonyl) H2NCO− carbanilino = [(phenylamino)carbonyl] PhNHCO− carbaniloyl = [(phenylamino)carbonyl] PhNHCO− carbazimidoyl = (hydrazinyliminomethyl) H2NNHC(=NH)− carbazol-9-yl = 9H-carbazol-9-yl (C12H8N)− carbazoyl = (hydrazinylcarbonyl) H2NNHCO− carbethoxy = (ethoxycarbonyl) EtO2C− carbobenzoxy = [(phenylmethoxy)carbonyl] PhCH2O2C− carbonimidoyl7 (see also (iminomethyl)) −C(=NH)− carbonothioyl7 (see also (thioxomethyl)) −CS− carbonyl −CO− (carbonyldioxy) = [carbonylbis(oxy)] −OCO2− (1-carbonylethyl) = (1-methyl-2-oxoethenyl) O=C=CMe− (carbonylmethyl) = (2-oxoethenyl) O=C=CH− (carbonylmethylene) = (1-oxo-1,2-ethanediyl) −COCH2− or (2-oxoethenylidene) O=C=C= carboxy4 HO2C− (carboxyformyl) = (carboxycarbonyl) HO2CCO− (5-carboxyvaleryl) = (5-carboxy-1-oxopentyl) HO2C(CH2)4CO− carnosyl = (N-β-alanylhistidyl)1 or [2-[(3-amino1-oxopropyl)amino]-3-(1H-imidazol-4-yl)-1oxopropyl] 3 cyanamido = (cyanoamino) NCNH− cyanato NCO− cyano NC− cyclodisiloxan-2-yl 1 4 O O 3 carvomenthyl = ethyl)cyclohexyl] Me2CH Me [2-methyl-5-(1-methyl- 2 H2Si SiH 6 1 Me 10-caryl = [(7,7-dimethylbicyclo[4.1.0]hept-3yl)methyl] (C9H15)CH2− cathyl = [(ethoxycarbonyl)oxy] EtOCO2− cedranyl = (octahydro-3a,6,8,8-tetramethyl-1H3a,7-methanoazulenyl) (C15H25)− cetyl = hexadecyl Me(CH2)15− chaulmoogroyl (from chaulmoogric acid) = [13(2-cyclopenten-1-yl)-1-oxotridecyl] C5H7(CH2)12CO− chaulmoogryl (from chaulmoogryl alcohol) = [13(2-cyclopenten-1-yl)tridecyl] C5H7(CH2)13− chloro Cl− (chloroformyl) = (chlorocarbonyl) ClCO− (chloroglyoxyloyl) = (2-chloro-2-oxoacetyl) ClCOCO− (chlorooxalyl) = (2-chloro-2-oxoacetyl) ClCOCO− chlorosyl OCl− chloryl O2Cl− cholesteryl (from cholesterol) = cholest-5-en-3-yl (from cholestene) (C27H45)− choloyl (from cholic acid) = (3,7,12-trihydroxy-24oxocholan-24-yl) (HO)3(C23H36)CO− chromanyl = (3,4-dihydro-2H-1-benzopyranyl) (C9H9O)− cinchoninoyl (from cinchoninic acid) = (4-quinolinylcarbonyl) (4−C9H6N)CO− cinnamal = (3-phenyl-2-propen-1-ylidene) PhCH=CHCH= cinnamenyl = (2-phenylethenyl) PhCH=CH− cinnamoyl = (1-oxo-3-phenyl-2-propen-1-yl) PhCH=CHCO− cinnamyl = (3-phenyl-2-propen-1-yl) PhCH=CHCH2− cinnamylidene = (3-phenyl-2-propen-1-ylidene) PhCH=CHCH= citraconimido = (2,5-dihydro-3-methyl-2,5-dioxo1H-pyrrol-1-yl) O 5 1 cyclohexadienylene = cyclohexadienediyl −C6H6− cyclohexanecarboxamido = [(cyclohexylcarbonyl)amino] C6H11CONH− 1,2-cyclohexanedicarboximido = (octahydro-1,3dioxo-2H-isoindol-2-yl) O N O cymyl = [methyl(1-methylethyl)phenyl] Me(Me2CH)C6H3− cysteinyl1 = (2-amino-3-mercapto-1-oxopropyl) HSCH2CH(NH2)CO− cysteyl = (3-sulfoalanyl)1 or (2-amino-1-oxo-3-sulfopropyl) HO3SCH2CH(NH2)CO− dansyl = [[5-(dimethylamino)-1-naphthalenyl]sulfonyl] SO 2 Me2 N N Me O citraconoyl = (2-methyl-1,4-dioxo-2-butene-1,4diyl) −COCMe=CHCO− conaninyl (from conanine) (C22H36N)− cresotoyl (from cresotic acid) = (hydroxymethylbenzoyl) HO(Me)C6H3CO− cresoxy = (methylphenoxy) MeC6H4O− cresyl = (hydroxymethylphenyl) HO(Me)C6H3− or (methylphenyl) MeC6H4− cresylene = (methylphenylene) −(MeC6H3)− crotonoyl = (1-oxo-2-buten-1-yl) MeCH=CHCO− crotonyl = (1-oxo-2-buten-1-yl) MeCH=CHCO− crotyl = 2-buten-1-yl MeCH=CHCH2− cumal = [[4-(1-methylethyl)phenyl]methylene] 4−(Me2CH)C6H4CH= cumenyl = [(1-methylethyl)phenyl] Me2CHC6H4− cumidino = [[4-(1-methylethyl)phenyl]amino] 4-(Me2CH)C6H4NH− cuminal = [[4-(1-methylethyl)phenyl]methylene] 4−(Me2CH)C6H4CH= cuminyl = [[4-(1-methylethyl)phenyl]methyl] 4−(Me2CH)C6H4CH2− cuminylidene = [[4-(1-methylethyl)phenyl]methylene] 4−(Me2CH)C6H4CH= cumoyl = [4-(1-methylethyl)benzoyl] 4−(Me2CH)C6H4CO− cumyl8 = [(1-methylethyl)phenyl] (Me2CH)C6H4− α-cumyl = (1-methyl-1-phenylethyl) −PhCMe2− N HN CH2CH NHCO(CH 2) 2NH 2 CO — 15 caronaldehydoyl = [(3-formyl-2,2-dimethylcyclopropyl)carbonyl] HCO Me 3 1 CO Me decanedioyl = (1,10-dioxo-1,10-decanediyl) −CO(CH2)8CO− decanoyl = (1-oxodecyl) CH3(CH2)8CO− decasiloxanylene = 1,19-decasiloxanediyl −SiH2(OSiH2)8OSiH2− desyl = (2-oxo-1,2-diphenylethyl) PhCOCHPh− diarsenyl HAs=As− diarsinetetrayl = 1,2-diarsinediylidene =AsAs= diarsinyl H2AsAsH− 1,2-diazenediyl = −N=N− diazeno = diazenyl HN=N− or −N=N− diazo5 (see also isodiazenylidene) N2= diazoamino = 1-triazene-1,3-diyl −NHN=N− diazonio N2+− dibenzothiophene-yl = dibenzothienyl (C12H7S)− diborane(4)tetrayl = 1,2-diborane(4)diylidene =BB= 1,2-dicarbadodecaboran(12)-1-yl (C2H11B10)− digermanylene = 1,2-digermanediyl −GeH2GeH2− digermthianyl = 1-digermathianyl H3GeSGeH2− diglycoloyl = [oxybis(1-oxo-2,1-ethanediyl)] −COCH2OCH2CO− (dimethyliminio) Me2N+= dioxy9 (see also epidioxy) −OO− 1,2-diphosphinediyl −PHPH− diphosphinetetrayl = 1,2-diphosphinediylidene =PP= diphosphino = diphosphinyl H2PPH− diphosphinylidene H2P−P= diseleno9 (see also epidiseleno and seleninoselenoyl) −SeSe− disilanoxy = (disilanyloxy) H3SiSiH2O− disilanyl H3SiSiH2− disilanylene = 1,2-disilanediyl −SiH2SiH2− disilazanoxy = (1-disilazanyloxy) H3SiNHSiH2O− 1-disilazanyl H3SiNHSiH2− 2-disilazanyl = (disilylamino) (H3Si)2N− disiloxanediylidene = 1,3-disiloxanediylidene =SiHOSiH= disiloxanoxy = (1-disiloxanyloxy) H3SiOSiH2O− disiloxanylene = 1,3-disiloxanediyl −SiH2OSiH2− disilthianoxy = (1-disilathianyloxy) H3SiSSiH2O− distannanylene = 1,2-distannanediyl −SnH2SnH2− distannthianediylidene = 1,3-distannathianediylidene =SnHSSnH= 6 −S(O)S(O)− disulfinyl disulfonyl6 −SO2SO2− dithio9 (see also epidithio and sulfinothioyl) −SS− ¶ 294 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 (formimidoylmethyl) = (2-iminoethyl) HC(=NH)CH2− formyl4 HCO− fucosyl = (6-deoxygalactosyl) (C6H11O4)− fumaraniloyl = [1,4-dioxo-4-(phenylamino)-2buten-1-yl] PhNHCOCH=CHCO− fumaroyl = (1,4-dioxo-2-butene-1,4-diyl) −COCH=CHCO− furfural = (2-furanylmethylene) 1 5 120 (dithiobicarbamoyl) = (1,2-hydrazinediyldicarbonothioyl) −CSNHNHCS− (dithiocarboxy) HS2C− (dithiohydroperoxy) = (thiosulfeno)4 HSS− dodecanoyl = (1-oxododecyl) Me(CH2)10CO− duryl = (2,3,5,6-tetramethylphenyl) 2,3,5,6Me4C6H− durylene = (2,3,5,6-tetramethyl-1,4-phenylene) −(2,3,5,6−Me4C6)− enanthoyl = (1-oxoheptyl) Me(CH2)5CO− enanthyl = (1-oxoheptyl) Me(CH2)5CO− epidioxy10 (see also dioxy) −OO− epidiseleno10 (See also diseleno and seleninoselenoyl) −SeSe− epidithio10 (see also dithio and sulfinothioyl) −SS− epioxy = epoxy (see also oxy and oxo) −O− episeleno10 (see also seleno and selenoxo) −Se− epithio10 (see also thio and thioxo) −S− epoxy10 (See also oxy and oxo) −O− (epoxyethyl) = 2-oxiranyl 1O 3 ylethyl)-6-azulenyl] (C15H27)− guanidino = [(aminoiminomethyl)amino] H2NC(=NH)NH− (guanidinoazo) = [3-(aminoiminomethyl)-1-triazen-1-yl] H2NC(=NH)NHN=N− guanyl = (aminoiminomethyl) H2NC(=NH)− heptadecanoyl = (1-oxoheptadecyl) Me(CH2)15CO− heptanamido = [(1-oxoheptyl)amino] Me(CH2)5CONH− heptanedioyl = (1,7-dioxo-1,7-heptanediyl) −CO(CH2)5CO− heptanoyl = (1-oxoheptyl) Me(CH2)5CO− hexadecanoyl = (1-oxohexadecyl) Me(CH2)14CO− 2,4-hexadiynylene = 2,4-hexadiyne-1,6-diyl −CH2C≡CC≡CCH2− hexamethylene = 1,6-hexanediyl −(CH2)6− hexanedioyl = (1,6-dioxo-1,6-hexanediyl) −CO(CH2)4CO− hexanethioyl = (1-thioxohexyl) Me(CH2)4CS− hippuroyl = (N-benzoylglycyl)1 or [2-(benzoylamino)acetyl] BzNHCH2CO− hippuryl = (N-benzoylglycyl)1 or [2-(benzoylamino)acetyl] BzNHCH2CO− histidyl1 = [2-amino-3-(1H-imidazol-4-yl)-1-oxopropyl] 3 O CH furfuryl = (2-furanylmethyl) 1 5 O CH2 furfurylidene = (2-furanylmethylene) 1 5 O CH (2,3-epoxypropyl) = (2-oxiranylmethyl) 1 3 O furoyl = (furanylcarbonyl) (C4H3O)CO− furyl = furanyl (C4H3O)− galloyl = (3,4,5-trihydroxybenzoyl) 3,4,5−(HO)3C6H2CO− gentisoyl = (2,5-dihydroxybenzoyl) 2,5-(HO)2C6H3CO− geranyl (from geraniol) = (3,7-dimethyl-2,6-octadien-1-yl) Me2C=CH(CH2)2CMe=CHCH2− germacran-6-yl = [5,9-dimethyl-2-(1-methylethyl)cyclodecyl] (C15H25)− germanetetrayl =Ge= germyl H3Ge− germylene H2Ge= germylidyne HGe≡ gibbanyl (from gibbane) (C15H23)− (glucosyloxy) (C6H11O5)O− glutaminyl1 = (2,5-diamino-1,5-dioxopentyl) H2NCO(CH2)2CH(NH2)CO− α-glutaminyl1 = (4,5-diamino-1,5-dioxopentyl) H2NCOCH(NH2)CH2CH2CO− glutamoyl1 = (2-amino-1,5-dioxo-1,5-pentanediyl) −CO(CH2)2CH(NH2)CO− glutamyl = glutamoyl or unspecified glutamyl (see below) α-glutamyl1 = (2-amino-4-carboxy-1-oxobutyl) HO2C(CH2)2CH(NH2)CO− γ-glutamyl1 = (4-amino-4-carboxy-1-oxobutyl) HO2CCH(NH2)(CH2)2CO− glutaryl = (1,5-dioxo-1,5-pentanediyl) −CO(CH2)3CO− glyceroyl = (2,3-dihydroxy-1-oxopropyl) HOCH2CH(OH)CO− glyceryl = 1,2,3-propanetriyl −CH(CH2−)2 glycidyl = (2-oxiranylmethyl) 1 3 CH 2 N HN 1 5 eremophilan-1-yl = [decahydro-4,4a-dimethyl-5(1-methylethyl)-1-naphthalenyl] (C15H27)− ethanediylidene = 1,2-ethanediylidene =CHCH= 1,2-ethenediyl −CH=CH− ethinyl = ethynyl HC≡C− ethoxalyl = (2-ethoxy-2-oxoacetyl) EtO2CCO− ethoxy EtO− (ethoxycarbonyl) EtO2C− (1-ethoxyformimidoyl) = (ethoxyiminomethyl) EtOCH(=NH)− (ethoxyphosphinyl) EtOPH(O)− ethyl Et (MeCH2−) ethylene = 1,2-ethanediyl −CH2CH2− [ethylenebis(nitrilodimethylene)] = [1,2ethanediylbis[nitrilobis(methylene)] (−CH2)2N(CH2)2N(CH2−)2 (ethylenedioxy) = [1,2-ethanediylbis(oxy)] −O(CH2)2O− ethylidene CH3CH= ethylidyne CH3C≡ 1-ethylium-1-ylidene CH3C+= (ethyloxy) = ethoxy EtO− (ethylselenyl) = (ethylseleno) EtSe− (ethylthio) EtS− eudesman-8-yl = [decahydro-5,8a-dimethyl-2-(1methylethyl)-2-naphthalenyl] (C15H27)− farnesyl (from farnesol) = (3,7,11-trimethyl2,6,10-dodecatrien-1-yl) Me2C=CH(CH2)2CMe=CH(CH2)2CMe=CHCH2− fenchyl = (1,3,3-trimethylbicyclo[2.2.1]hept-2-yl) (C10H17)− 1,1′-ferrocenediyl −(C5H4)Fe(C5H4)− fluoranyl = (3-oxospiro[isobenzofuran-1(3H),9′[9H]xanthen]yl) (C20H11O3)− fluoren-9-ylidene = 9H-fluoren-9-ylidene (C13H8)= fluoro F− formamido = (formylamino) HCONH− 1-formazano = [2-(hydrazinylidenemethyl)diazenyl] H2NN=CHN=N− 5-formazano = [2-(diazenylmethylene)hydrazinyl] HN=NCH=NNH− formazanyl = (diazenylhydrazinylidenemethyl) HN=N−C(=NNH2)− formazyl = [(2-phenyldiazenyl)(2-phenylhydrazinylidene)methyl] PhN=NC(=NNHPh)− formimidoyl = (iminomethyl) CH(=NH)− (1-formimidoylformimidoyl) = (1,2-diiminoethyl) HC(=NH)C(=NH)− (formimidoylformyl) = (2-iminoacetyl) CH(=NH)CO− CH2CH(NH2)CO O CH 2 glycinamido = [(2-aminoacetyl)amino] H2NCH2CONH− glycinimidoyl = (2-amino-1-iminoethyl) H2NCH2C(=NH)− glycoloyl = (2-hydroxyacetyl) HOCH2CO− glycolyl = (2-hydroxyacetyl) HOCH2CO− glycyl1 = (2-aminoacetyl) H2NCH2CO− glyoxalinyl = imidazolyl (C3H3N2)− glyoxylimidoyl = (1-imino-2-oxoethyl) HCOC(=NH)− glyoxyloyl = (2-oxoacetyl) HCOCO− (glyoxyloylmethyl) = (2,3-dioxopropyl) HCOCOCH2− glyoxylyl = (2-oxoacetyl) HCOCO− guaiacyl = (4-hydroxy-3-methoxyphenyl) 4−OH−3−(CH3O)C6H3− or (2-methoxyphenyl) 2−(MeO)C6H4− guaian-8-yl = [decahydro-1,4-dimethyl-7-(1-meth- homocysteinyl1 = (2-amino-4-mercapto-1-oxobutyl) HS(CH2)2CH(NH2)CO− homomyrtenyl = [2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethyl] (C9H13)CH2CH2− homopiperonyl = [2-(1,3-benzodioxol-5-yl)ethyl] (C7H5O2)CH2CH2− homoseryl1 = (2-amino-4-hydroxy-1-oxobutyl) HO(CH2)2CH(NH2)CO− homoveratroyl = [2-(3,4-dimethoxyphenyl)acetyl] 3,4−(MeO)2C6H3CH2CO− homoveratryl [2-(3,4-dimethoxyphenyl)ethyl] 3,4−(MeO)2C6H3CH2CH2− hydantoyl = [N-(aminocarbonyl)glycyl]1 or [2[(aminocarbonyl)amino]acetyl] H2NCONHCH2CO− hydnocarpoyl (from hydnocarpic acid) = [11-(2cyclopenten-1-yl)-1-oxoundecyl] (C5H7)(CH2)10CO− hydnocarpyl (from hydnocarpyl alcohol) = [11-(2cyclopenten-1-yl)undecyl] (C5H7)(CH2)10CH2− hydracryloyl = (3-hydroxy-1-oxopropyl) HO(CH2)2CO− hydratropoyl = (1-oxo-2-phenylpropyl) PhCHMeCO− hydrazi = diaziridine (component ring in a spiro name) −NHNH− 1,2-hydrazinediyl −NHNH− 1,2-hydrazinediylidene =NN= hydrazinyl H2NNH− hydrazinylidene H2NN= 1-hydrazinyl-2-ylidene −NHN= hydrazo = 1,2-hydrazinediyl hydrazono = hydrazinylidene hydrocinnamoyl = (1-oxo-3-phenylpropyl) Ph(CH2)2CO− hydrocinnamyl = (3-phenylpropyl) Ph(CH2)3− hydroperoxy4 HOO− (hydroperoxyformyl) = (hydroperoxycarbonyl) HOOCO− hydroxamino = (hydroxyamino) HONH− hydroximino = (hydroxyimino) HON= hydroxy4 HO− (hydroxyarsinylidene) = arsinico3,4 HOAs(O)= hydroxyl = hydroxy4 HO− (hydroxyphosphinyl) HOPH(O)− (hydroxyphosphinylidene) = phosphinico3,4 HOP(O)= 121 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 isophthaloyl = (1,3-phenylenedicarbonyl) 1,3−C6H4(CO−)2 isophthalylidene = (1,3-phenylenedimethylidyne) 1,3−C6H4(CH=)2 isopropenyl = (1-methylethenyl) H2C=CMe− isopropoxy = (1-methylethoxy) Me2CHO− isopropyl = (1-methylethyl) Me2CH− isopropylidene = (1-methylethylidene) Me2C= (isopropylidenedioxy) = [(1-methylethylidene)bis(oxy)] −OCMe2O− isosemicarbazido = [2-(aminohydroxymethylene)hydrazinyl] H2NC(OH)=NNH− isothiocyanato SCN− isothiocyano = isothiocyanato SCN− isovaleryl = (3-methyl-1-oxobutyl) Me2CHCH2CO− isovalyl1 = (2-amino-2-methyl-1-oxobutyl) EtCMe(NH2)CO− isoviolanthrenylene = (9,18-dihydrodinaphtho[1,2,3-cd:1′,2′,3′-lm]perylenediyl) −(C34H18)− kauranyl (from kaurane) (C20H33)− kauranylene = kauranediyl (from kaurane) −(C20H32)− kaurenyl (from kaurene) (C20H31)− keto11 = oxo O= labdan-15-yl = [5-(decahydro-2,5,5,8a-tetramethyl-1-naphthalenyl)-3-methylpentyl] (C20H37)− lactosyl = (4-O-β-galactapyranosyl-β-D-glucopyranosyl) (C6H11O5)O(C6H10O5)− lactoyl = (2-hydroxypropanoyl)1 or (2-hydroxy-1oxopropyl) MeCH(OH)CO− lanostenylene = lanostenediyl (from lanostane) −(C30H50)− lauroyl = (1-oxododecyl) Me(CH2)10CO− leucyl1 = (2-amino-4-methyl-1-oxopentyl) Me2CHCH2CH(NH2)CO− levulinoyl = (1,4-dioxopentyl) MeCO(CH2)2CO− linalyl (from linalool) = (1-ethenyl-1,5-dimethyl-4hexen-1-yl) Me2C=CH(CH2)2CMe(CH=CH2)− linolelaidoyl = (1-oxo-9,12-octadecadien-1-yl) Me(CH2)4CH=CHCH2CH=CH(CH2)7CO− linolenoyl = (1-oxo-9,12,15-octadecatrien-1-yl) EtCH=CHCH2CH=CHCH2CH=CH(CH2)7CO− γ-linolenoyl = (1-oxo-6,9,12-octadecatrien-1-yl) Me(CH2)4CH=CHCH2CH=CHCH2CH=CH(CH2)4CO− linoleoyl = (1-oxo-9,12-octadecadien-1-yl) Me(CH2)4CH=CHCH2CH=CH(CH2)7CO− lupanyl (from lupane) (C30H51)− lysyl1 = (2,6-diamino-1-oxohexyl) H2N(CH2)4CH(NH2)CO− maleoyl = (1,4-dioxo-2-butene-1,4-diyl) −COCH=CHCO− malonaldehydoyl = (1,3-dioxopropyl) HCOCH2CO− malonamoyl = (3-amino-1,3-dioxopropyl) H2NCOCH2CO− malonaniloyl = [1,3-dioxo-3-(phenylamino)propyl] PhNHCOCH2CO− malonimido = (2,4-dioxo-1-azetidinyl) O 6 4 ¶ 294 hygroyl = (1-methylprolyl)1 or [(1-methyl-2-pyrrolidinyl)carbonyl] Me N 1 1,3-cyclohexanediyl] CHMe2 5 6 1 CO Me mercapto4 HS− mesaconoyl = (2-methyl-1,4-dioxo-2-butene-1,4diyl) −COCMe=CHCO− mesidino = [(2,4,6-trimethylphenyl)amino] 2,4,6−Me3C6H2NH− mesityl = (2,4,6-trimethylphenyl) 2,4,6−Me3C6H2− α-mesityl = [(3,5-dimethylphenyl)methyl] 3,5−Me2C6H3CH2− mesoxalyl = (1,2,3-trioxo-1,3-propanediyl) −COCOCO− mesyl = (methylsulfonyl) MeSO2− metanilamido = [[(3-aminophenyl)sulfonyl]amino] 3−H2NC6H4SO2NH− metanilyl = [(3-aminophenyl)sulfonyl] 3−H2NC6H4SO2− methacryloyl = (2-methyl-1-oxo-2-propen-1-yl) H2C=CMeCO− methallyl = (2-methyl-2-propen-1-yl) H2C=CMeCH2− methanetetrayl =C= methene = methylene H2C= methenyl = methylidyne HC≡ methionyl (from methionic acid) = [methylenebis(sulfonyl)] −SO2CH2SO2− methionyl1 (from methionine) = [2-amino-4(methylthio)-1-oxobutyl] MeS(CH2)2CH(NH2)CO− methoxalyl = (2-methoxy-2-oxoacetyl) MeO2CCO− methoxy MeO− (methoxycarbonyl) MeO2C− methyl Me (H3C)− [(methyldithio)sulfonyl] MeSSSO2− methylene H2C= (methylenedioxy) = [methylenebis(oxy)] −OCH2O− [(methylenedioxy)phenyl] = 1,3-benzodioxol-aryl (CH2O2)C6H3− (methylenedisulfonyl) = [methylenebis(sulfonyl)] −SO2CH2SO2− methylidyne HC≡ methyliumylidene C+H= methylol = (hydroxymethyl) HOCH2− (methyloxy) = methoxy MeO− (1-methyl-2H-pyranium-2-yl) 6 imidazolidyl = imidazolidinyl (C3H7N2)− imidazolinyl = (dihydro-1H-imidazolyl) (C3H5N2)− imidocarbonyl = carbonimidoyl7 −C(=NH)− (imidocarbonylamino) = (carbonimidoylamino) HN=C=N− imino HN= iminio H2N+= (3-iminoacetonyl) = (3-imino-2-oxopropyl) HN=CHCOCH2− (iminodisulfonyl) = [iminobis(sulfonyl)] −SO2NHSO2− (iminomethyl) (see also carbonimidoyl) HN=CH− (iminonitrilo) = 1-hydrazinyl-2-ylidene −NHN= (iminophosphoranyl) = phosphinimyl H2P(=NH)− indanyl = (2,3-dihydro-1H-indenyl) (C9H9)− indenyl = 1H-indenyl (C9H7)− 1-indolinyl = (2,3-dihydro-1H-indol-1-yl) (C8H8N)− 2-indolinylidene = (1,3-dihydro-2H-indol-2ylidene) (C8H7N)= indyl = 1H-indolyl (C8H6N)− iodo I− iodoso = iodosyl OI− iodoxy = iodyl O2I− isoallyl = 1-propen-1-yl MeCH=CH− isoamoxy = (3-methylbutoxy) Me2CH(CH2)2O− isoamyl = (3-methylbutyl) Me2CH(CH2)2− sec-isoamyl = (1,2-dimethylpropyl) Me2CHCHMe− isoamylidene = (3-methylbutylidene) Me2CHCH2CH= isobornyl (from isoborneol) = (1,7,7-trimethylbicyclo[2.2.1]hept-2-yl) (C10H17)− isobutenyl = (2-methyl-1-propen-1-yl) Me2C=CH− isobutoxy = (2-methylpropoxy) Me2CHCH2O− isobutyl = (2-methylpropyl) Me2CHCH2− isobutylidene = (2-methylpropylidene) Me2CHCH= isobutyryl = (2-methyl-1-oxopropyl) Me2CHCO− isocrotyl = (2-methyl-1-propen-1-yl) Me2C=CH− isocyanato OCN− isocyano CN− −+ isodiazenyl N=NH− isodiazenylidene6 (see also diazo) N−=N+= isohexyl = (4-methylpentyl) Me2CH(CH2)3− isohexylidene = (4-methylpentylidene) Me2CH(CH2)2CH= 2-isoindolinyl = (1,3-dihydro-2H-isoindol-2-yl) (C8H8N)− isoleucyl1 = (2-amino-3-methyl-1-oxopentyl) EtCHMeCH(NH2)CO− isonicotinoyl = (4-pyridinylcarbonyl) 1N Me O+ 1 (1-methylpyridinium-2-yl) Me N+ CO 1 isonipecotoyl = (4-piperidinylcarbonyl) CO O N HN 1 6 (methylselenyl) = (methylseleno) MeSe− (methylthio) MeS− (methyltelluro) MeTe− (methyltrioxy) MeOOO− morpholino = 4-morpholinyl 4 1 isonitro = aci-nitro HON(O)= isonitroso = (hydroxyimino) HON= 1-isopentenyl = (3-methyl-1-buten-1-yl) Me2CHCH=CH− isopentyl = (3-methylbutyl) Me2CH(CH2)2− isopentylidene = (3-methylbutylidene) Me2CHCH2CH= isophthalal = (1,3-phenylenedimethylidyne) 1,3−C6H4(CH=)2 isophthalaldehydoyl = (3-formylbenzoyl) 3−(HCO)C6H4CO− malonyl = (1,3-dioxo-1,3-propanediyl) −COCH2CO− maloyl = (2-hydroxy-1,4-dioxo-1,4-butanediyl) −COCH(OH)CH2CO− maltosyl = (4-O-α-D-glucopyranosyl-β-D-glucopyranosyl) (C6H11O5)O(C6H10O5)− mandeloyl = (2-hydroxy-2-phenylacetyl) PhCH(OH)CO− p-menth-2-yl = [2-methyl-5-(1-methylethyl)cyclohexyl] 2,5−Me(Me2CH)C6H9− p-menth-3,5-ylene = [5-methyl-2-(1-methylethyl)- O 6 N myristoyl = (1-oxotetradecyl) Me(CH2)12CO− naphthal = (naphthalenylmethylene) (C10H7)CH= naphthalimido = (1,3-dioxo-1H-benz[de]isoquinolin-2(3H)-yl) (C12H6NO2)− naphthenyl = (naphthalenylmethylidyne) (C10H7)C≡ ¶ 294 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 oxamoyl = (2-amino-2-oxoacetyl) H2NCOCO− oxamyl = (2-amino-2-oxoacetyl) H2NCOCO− oxaniloyl = [2-oxo-2-(phenylamino)acetyl] PhNHCOCO− oxazolinyl = (dihydrooxazolyl) (C3H4NO)− oximido = (hydroxyimino) HON= oxo5 (See also epoxy and oxy) O= (oxoarsino) = arsenoso OAs− (oxobornyl) = (trimethyloxobicyclo[2.2.1]heptyl) (C10H15O)− (oxoboryl) OB− (1-oxoethyl) = acetyl Ac (MeCO−) (oxoethylene) = (1-oxo-1,2-ethanediyl) −COCH2− (2-oxo-2-phenylhydrazinyl) = (nitrosophenylamino) PhN(NO)− (oxophenylmethyl) = benzoyl Bz (PhCO−) (oxophosphino) = phosphoroso OP− (oxopyridinylmethyl) = (pyridinylcarbonyl) (C5H4N)CO− (2-oxotrimethylene) = (2-oxo-1,3-propanediyl) −CH2COCH2− (2-oxovinyl) = (2-oxoethenyl) OC=CH− oxy9 (see also epoxy and oxo) −O− [oxybis(methylenecarbonylimino)] = [oxybis[(1oxo-2,1-ethanediyl)imino]] −NHCOCH2OCH2CONH− palmitoyl = (1-oxohexadecyl) Me(CH2)14CO− pantothenoyl = N-(2,4-dihydroxy-3,3-dimethyl-1oxobutyl)-β-alanyl1 or [3-[(2,4-dihydroxy-3,3dimethyl-1-oxobutyl)amino]-1-oxopropyl] HOCH2CMe2CH(OH)CONH(CH2)2CO− pelargonoyl = (1-oxononyl) Me(CH2)7CO− pelargonyl = (1-oxononyl) Me(CH2)7CO− pentadecanoyl = (1-oxopentadecyl) Me(CH2)13CO− pentamethylene = 1,5-pentanediyl −(CH2)5− 3-pentanesulfonamido = [[(1-ethylpropyl)sulfonyl]amino] Et2CHSO2NH− 1,3-pentazadieno = 1,3-pentazadien-1-yl H2NN=NN=N− 2-pentenediylidyne = 2-pentene-1,5-diylidyne ≡CCH=CHCH2C≡ tert-pentyl = (1,1-dimethylpropyl) EtCMe2− pentyl Me(CH2)4− pentylidyne BuC≡ perchloryl O3Cl− perseleno = seleninoselenoyl Se=Se= perthio = sulfinothioyl S=S= phenacyl = (2-oxo-2-phenylethyl) PhCOCH2− phenacylidene = (2-oxo-2-phenylethylidene) PhCOCH= phenanthrothiophene-yl = phenanthrothienyl (C16H9S)− phenanthryl = phenanthrenyl (C14H9)− phenanthrylene = phenanthrenediyl −(C14H8)− phenenyl = benzenetriyl C6H3≡ phenethyl = (2-phenylethyl) PhCH2CH2− phenethylidene = (2-phenylethylidene) PhCH2CH= phenetidino = [(ethoxyphenyl)amino] (EtO)C6H4NH− phenetyl = (ethoxyphenyl) (EtO)C6H4− phenoxy PhO− phenyl Ph (C6H5)− phenylalanyl1 (from phenylalanine) = (2-amino-1oxo-3-phenylpropyl) PhCH2CH(NH2)CO− (phenylarsinico) = (hydroxyphenylarsinyl) PhAs(O)(OH)− (phenylazo) = (2-phenyldiazenyl) PhN=N− [(phenylazo)imino] = (3-phenyl-2-triazen-1ylidene) PhN=NN= (phenylbenzoyl) = ([1,1′-biphenyl]ylcarbonyl) PhC6H4CO phenylene −(C6H4)− [phenylenebis(azo)] = [phenylenebis(2,1-diazenediyl)] −N=NC6H4N=N− [phenylenebis[2,1-diazenediyl(methylimino)]] = [phenylenebis(1-methyl-2-triazene-3,1-diyl)] −NMeN=NC6H4N=NNMe− [phenylenebis(1-oxo-1-ethanyl-2-ylidene)] = [phenylenebis(2-oxo-2-ethanyl-1-ylidene)] =CHCOC6H4COCH= (phenylenedimethylene) = [phenylenebis(methyl- 122 naphthionyl = [(4-amino-1-naphthalenyl)sulfonyl] 4,1−H2NC10H6SO2− naphthobenzyl = (naphthalenylmethyl) (C10H7)CH2− naphthothiophene-yl = naphthothienyl (C12H7S)− naphthoxy = (naphthalenyloxy) (C10H7)O− naphthoyl = (naphthalenylcarbonyl) (C10H7)CO− naphthyl = naphthalenyl (C10H7)− naphthylene = naphthalenediyl −(C10H6)− 1(2H)-naphthylidene = 1(2H)-naphthalenylidene CH2 (naphthylnaphthyl) = [binaphthalen]yl C10H7C10H6− nazyl = (naphthalenylmethyl) (C10H7)CH2− neopentyl = (2,2-dimethylpropyl) Me3CCH2− neophyl = (2-methyl-2-phenylpropyl) PhCMe2CH2− neryl (from nerol) = (3,7-dimethyl-2,6-octadien-1yl) −Me2C=CH(CH2)2CMe=CHCH2− nicotinimidoyl = (imino-3-pyridinylmethyl) (C5H4N)C(=NH)− nicotinoyl = (3-pyridinylcarbonyl) 1 N 6 CO nipecotoyl = (3-piperidinylcarbonyl) 1 HN 6 CO nitramino = (nitroamino) O2NNH− aci-nitramino = (aci-nitroamino) HON(O)=N− nitrilio HN+≡ nitrilo N≡ (nitrilophosphoranyl) = phosphononitridyl HP(≡N)− nitro O2N− aci-nitro HON(O)= nitrosamino = (nitrosoamino) ONNH− nitrosimino = (nitrosoimino) ONN= nitroso ON− (nitrothio) O2NS− nonanedioyl = (1,9-dioxo-1,9-nonanediyl) −CO(CH2)7CO− nonanoyl = (1-oxononyl) Me(CH2)7CO− norbornyl = bicyclo[2.2.1]heptyl (C7H11)− norbornylene = bicyclo[2.2.1]heptanediyl −(C7H10)− norcamphanyl = bicyclo[2.2.1]heptyl (C7H11)− norcaryl (from norcarane) = bicyclo[4.1.0]heptyl (C7H11)− norpinyl (from norpinane) = bicyclo[3.1.1]heptyl (C7H11)− norleucyl1 = (2-amino-1-oxohexyl) Me(CH2)3CH(NH2)CO− norvalyl1 = (2-amino-1-oxopentyl) Me(CH2)2CH(NH2)CO− nosyl = [(4-nitrophenyl)sulfonyl] 4−O2NC6H4SO2− octadecanoyl = (1-oxooctadecyl) Me(CH2)16CO− octanedioyl = (1,8-dioxo-1,8-octanediyl) −CO(CH2)6CO− octanoyl = (1-oxooctyl) Me(CH2)6CO− tert-octyl = (1,1,3,3-tetramethylbutyl) Me3CCH2CMe2− oenanthyl = (1-oxoheptyl) Me(CH2)5CO− oleananyl (from oleanane) (C30H51)− oleoyl = (1-oxo-9-octadecen-1-yl) Me(CH2)7CH=CH(CH2)7CO− ornithyl1 = (2,5-diamino-1-oxopentyl) H2N(CH2)3CH(NH2)CO− oxalaldehydoyl = (2-oxoacetyl) HCOCO− oxalyl = (1,2-dioxo-1,2-ethanediyl) −COCO− oxamido = [(2-amino-2-oxoacetyl)amino] H2NCOCONH− ene)] −CH2C6H4CH2− (phenylenedimethylidyne) =CHC6H4CH= (phenylenedioxy) = [phenylenebis(oxy)] −OC6H4O− (phenylglyoxyloyl) = (2-oxo-2-phenylacetyl) PhCOCO− phenylidene = cyclohexadienylidene (C6H6)= (phenylimidocarbonyl) = (phenylcarbonimidoyl)7 PhN=C= (phenyloxalyl) = (2-oxo-2-phenylacetyl) PhCOCO− (phenyloxy) = phenoxy PhO− (phenylphenoxy) = ([1,1′-biphenyl]yloxy) PhC6H4O− (phenylsulfenyl) = (phenylthio) PhS− (phenylsulfinyl) PhS(O)− (S-phenylsulfonimidoyl) PhS(O)(=NH)− phorbinyl (from phorbine) (C22H17N4)− phosphinico3,4 HOP(O)= phosphinidene HP= phosphinidenio H2P+= phosphinidyne P≡ phosphinimyl H2P(=NH)− phosphino H2P− phosphinothioyl H2P(S)− phosphinothioylidene HP(S)= phosphinyl H2P(O)− phosphinylidene HP(O)= phosphinylidyne P(O)≡ phospho O2P− phosphonio H3P+− phosphono4 (HO)2P(O)− (phosphonoformyl) = (phosphonocarbonyl) (HO)2P(O)CO− phosphononitridyl HP(≡N)− phosphoranyl H4P− phosphoranylidene H3P= phosphoranylidyne H2P≡ phosphoro = 1,2-diphosphenediyl −P=P− phosphoroso OP− phthalal = (1,2-phenylenedimethylidyne) 1,2−C6H4(CH=)2 phthalaldehydoyl = (2-formylbenzoyl) 2−(HCO)C6H4CO− phthalamoyl = [2-(aminocarbonyl)benzoyl] 2−(H2NCO)C6H4CO− phthalanyl = (1,3-dihydroisobenzofuranyl) (C8H7O)− phthalidyl = (1,3-dihydro-3-oxo-1-isobenzofuranyl) (C8H5O2)− phthalidylidene = (3-oxo-1(3H)-isobenzofuranylidene) (C8H402)− phthalimido = (1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl) (C8H4NO2)− phthalocyaninyl1 (from phthalocyanine) (C32H17N8)− phthaloyl = (1,2-phenylenedicarbonyl) 1,2−C6H4(CO−)2 phthalylidene = (1,2-phenylenedimethylidyne) 1,2−C6H4(CH=)2 phyllocladanyl = kauranyl (from kaurane) (C29H33)− phytyl = (3,7,11,15-tetramethyl-2-hexadecen-1-yl) Me[CHMe(CH2)3]3CMe=CHCH2− picolinoyl = (2-pyridinylcarbonyl) 6 1 N CO picryl = (2,4,6-trinitrophenyl) 2,4,6−(O2N)3C6H2− pimeloyl = (1,7-dioxo-1,7-heptanediyl) −CO(CH2)5CO− 4-pinanyl (from pinane) = (4,6,6-trimethylbicyclo[3.1.1]hept-2-yl) (C10H17)− pinanylene = (trimethylbicyclo[3.1.1]heptanediyl) −(C10H16)− pipecoloyl = (2-piperidinylcarbonyl) 6 H N 1 CO 123 piperidino = 1-piperidinyl 6 1 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 pyridinio 6 ¶ 294 N piperidyl = piperidinyl (C5H10N)− piperidylidene = piperidinylidene (C5H9N)= piperonyl = (1,3-benzodioxol-5-ylmethyl) 3,4−(CH2O2)C6H3CH2− piperonylidene = (1,3-benzodioxol-5-ylmethylene) 3,4−(CH2O2)C6H3CH= piperonyloyl = (1,3-benzodioxol-5-ylcarbonyl) 3,4−(CH2O2)C6H3CO− pivaloyl = (2,2-dimethyl-1-oxopropyl) Me3CCO− pivalyl = (2,2-dimethyl-1-oxopropyl) Me3CCO− plumbanetetrayl =Pb= plumbyl H3Pb− plumbylene H2Pb= plumbylidyne HPb≡ podocarpan-13-yl = (tetradecahydro-4b,8,8-trimethyl-2-phenanthrenyl) (C17H29)− porphinyl (from porphine) (C20H13N4)− pregna-5,16-dien-21-yl (from pregnadiene) (C21H31)− prenyl = (3-methyl-2-buten-1-yl) Me2C=CHCH2− prolyl1 = (2-pyrrolidinylcarbonyl) 5 1 N + pyridyl = pyridinyl (C5H4N)− pyroglutamoyl = (5-oxoprolyl)1 or [(5-oxo-2-pyrrolidinyl)carbonyl] O 5 H N 1 CO pyromucyl = (2-furanylcarbonyl) 1 5 O CO pyrrolidyl = pyrrolidinyl (C4H8N)− pyrrolinyl = (dihydropyrrolyl) (C4H6N)− pyrrol-1-yl = 1H-pyrrol-1-yl (C4H4N)− pyrroyl = (pyrrolylcarbonyl) (C4H3N)CO− pyrryl = pyrrolyl (C4H4N)− pyruvoyl = (1,2-dioxopropyl) MeCOCO− p-quaterphenylyl = [1,1′:4′,1′′:4′′,1′′′-quaterphenyl]yl (C24H17)− quinaldoyl = (2-quinolinylcarbonyl) (2−C9H6N)CO− quinolyl = quinolinyl (C9H6N)− quinonyl = (dioxocyclohexadienyl) (C6H3O2)− quinuclidinyl = 1-azabicyclo[2.2.2]octyl (C7H12N)− α-resorcyloyl = (3,5-dihydroxybenzoyl) 3,5−(HO)2C6H3CO− β-resorcyloyl = (2,4-dihydroxybenzoyl) 2,4−(HO)2C6H3CO− γ-resorcyloyl = (2,6-dihydroxybenzoyl) 2,6−(HO)2C6H3CO− rhamnosyl = (6-deoxymannopyranosyl) HO Me HO OH O H N 1 CO 2-propanesulfonamido = [[(1-methylethyl)sulfonyl]amino] Me2CHSO2NH− propargyl = 2-propyn-1-yl HC≡CCH2 − propenyl = 1-propen-1-yl MeCH=CH− 2-propen-1-yl CH2=CH−CH2− propenylene = 1-propene-1,3-diyl −CH=CHCH2− propenylidene = 1-propen-1-ylidene MeCH=C= propioloyl = (1-oxo-2-propyn-1-yl) HC≡ CCO− propiolyl = (1-oxo-2-propyn-1-yl) HC≡ CCO − propionamido = [(1-oxopropyl)amino] EtCONH− propionyl = (1-oxopropyl) EtCO− (propionyldioxy) = [(1-oxopropyl)dioxy] EtC(O)OO− propionyloxy = (1-oxopropoxy) EtCO2− propoxy PrO− propyl Pr (CH3CH2CH2−) sec-propyl = (1-methylethyl) Me2CH− propylene = (1-methyl-1,2-ethanediyl) −CHMeCH2− propylidene EtCH= propylidyne EtC ≡ (propyloxy) = propoxy PrO− protocatechuoyl = (3,4-dihydroxybenzoyl) 3,4−(HO)2C6H3CO− pseudoallyl = (1-methylethenyl) H2C=CMe− pseudocumidino = [(2,4,5-trimethylphenyl)amino] 2,4,5−Me3C6H2NH− as-pseudocumyl = (2,3,5-trimethylphenyl) 2,3,5−Me3C6H2− s-pseudocumyl = (2,4,5-trimethylphenyl) 2,4,5−Me3C6H2− v-pseudocumyl = (2,3,6-trimethylphenyl) 2,3,6−Me3C6H2− pseudoindolyl = 1H-indolyl (C8H6N)− pteroyl = [4-[[(2-amino-3,4-dihydro-4-oxo-6-pteridinyl)methyl]amino]benzoyl] (C14H11N6O2)− 2H-pyranio 6 1 O+ senecioyl = (3-methyl-1-oxo-2-buten-1-yl) Me2C=CHCO− seryl1 = (2-amino-3-hydroxy-1-oxopropyl) HOCH2CH(NH2)CO− siamyl = (1,2-dimethylpropyl) Me2CHCHMe− silanetetrayl =Si= siloxy = (silyloxy) H3SiO− silyl H3Si− silylene H2Si= silylidyne HSi≡ sorboyl = (1-oxo-2,4-hexadien-1-yl) MeCH=CHCH=CHCO− spirohex-1-yl (C6H9)− spirostanyl (from spirostane) (C27H43O2)− stannanetetrayl =Sn= stannyl H3Sn− stannylene H2Sn= stannylidyne HSn ≡ stearoyl = (1-oxooctadecyl) Me(CH2)16CO− stibino H2Sb− stiboso = (oxostibino) OSb− stibyl = stibino H2Sb− stibylene HSb= stibylidyne Sb≡ styrene = (1-phenyl-1,2-ethanediyl) −CHPhCH2− styrolene = (1-phenyl-1,2-ethanediyl) −CHPhCH2− styryl = (2-phenylethenyl) PhCH=CH− suberoyl = (1,8-dioxo-1,8-octanediyl) −CO(CH2)6CO− succinaldehydoyl = (1,4-dioxobutyl) HCO(CH2)2CO− succinamoyl = (4-amino-1,4-dioxobutyl) H2NCO(CH2)2CO− succinamyl = (4-amino-1,4-dioxobutyl) H2NCO(CH2)2CO− succinaniloyl = [1,4-dioxo-4-(phenylamino)butyl] PhNHCO(CH2)2CO− succinimido = (2,5-dioxo-1-pyrrolidinyl) O 5 1 N O succinyl = (1,4-dioxo-1,4-butanediyl) −CO(CH2)2CO− sulfamino = (sulfoamino) HOSO2NH− sulfamoyl = (aminosulfonyl) H2NSO2− sulfamyl = (aminosulfonyl) H2NSO2− sulfanilamido = [[(4-aminophenyl)sulfonyl]amino] 4−H2NC6H4SO2NH− sulfanilyl = [(4-aminophenyl)sulfonyl] 4−H2NC6H4SO2− λ4-sulfanyl H2S= λ6-sulfanyl H4S= sulfeno4 HOS− sulfhydryl = mercapto4 HS− sulfinimidoyl HN=S= sulfino4 HOS(O)− sulfinothioyl S=S= sulfinyl OS= sulfinylhydrazono = (2-sulfinylhydrazinylidene) O=S=N−N= sulfo4 HO3S− sulfonimidoyl HN=S(O)= sulfonodiimidoyl (HN=)2S= sulfonyl −SO2− sulfurtetrayl =λ4-sulfanetetrayl =S= sulfurtriyl =λ4-sulfanylidyne HS≡ sulfuryl = sulfonyl −SO2− tartaroyl = (2,3-dihydroxy-1,4-dioxo-1,4-butanediyl) −COCH(OH)CH(OH)CO− tartronoyl = (2-hydroxy-1,3-dioxo-1,3-propanediyl) −COCH(OH)CO− tauryl = [(2-aminoethyl)sulfonyl] H2N(CH2)2SO2− λ4-tellanylidene H2Te= λ6-tellanylidene H4Te= telluro6 (see also telluroxo) −Te− telluroxo5 (see also telluro) Te= ricinelaidoyl = (12-hydroxy-1-oxo-9-octadecen-1yl) Me(CH2)5CH(OH)CH2CH=CH(CH2)7CO− ricinoleoyl = (12-hydroxy-1-oxo-9-octadecen-1yl) Me(CH2)5CH(OH)CH2CH=CH(CH2)7CO− rosan-6-yl = (2-ethyltetradecahydro-2,4a,8,8-tetramethyl-9-phenanthrenyl) (C20H35)− salicyl = [(2-hydroxyphenyl)methyl] 2−HOC6H4CH2− salicylidene = [(2-hydroxyphenyl)methylene] 2−HOC6H4CH= salicyloyl = (2-hydroxybenzoyl) 2−HOC6H4CO− sarcosyl = (N-methylglycyl)1 or [2-(methylamino)acetyl] MeNHCH2CO− sebacoyl = (1,10-dioxo-1,10-decanediyl) −CO(CH2)8CO− λ4-selanylidene H2Se= λ6-selanylidene H4Se= seleneno4 HOSe− selenino4 HOSe(O)− seleninoselenoyl Se=Se= seleninyl OSe= seleno9 (see also episeleno and selenoxo) −Se− selenocyanato NCSe− selenono4 (HO)SeO2− selenonyl O2Se= selenophenyl = selenophene-yl (C4H3Se)− selenoxo5 (see also episeleno and seleno) Se= selenyl4 HSe− semicarbazido = [2-(aminocarbonyl)hydrazinyl] H2NCONHNH− semicarbazono = [2-(aminocarbonyl)hydrazinylidene] H2NCONHN= 2H-pyran-2-ylium-2-yl 6 1 O + pyrazolidyl = pyrazolidinyl (C3H7N2)− pyrazolinyl = (dihydropyrazolyl) (C3H5N2)− ¶ 294 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 thiomorpholino = 4-thiomorpholinyl 4 1S 124 telluryl4 HTe− terephthalal = (1,4-phenylenedimethylidyne) 1,4−C6H4(CH=)2 terephthalaldehydoyl = (4-formylbenzoyl) 4−HCOC6H4CO− terephthalamoyl = [4-(aminocarbonyl)benzoyl] 4−(H2NCO)C6H4CO− terephthalaniloyl = [4-[(phenylamino)carbonyl]benzoyl] 4−(PhNHCO)C6H4CO− terephthaloyl = (1,4-phenylenedicarbonyl) 1,4−C6H4(CO−)2 terephthalylidene = (1,4-phenylenedimethylidyne) 1,4−C6H4(CH=)2 m-terphenylyl = [1,1′:3′,1′′-terphenyl]yl (C18H13)− terphenylylene = [terphenyl]diyl −(C18H12)− tetradecanoyl = (1-oxotetradecyl) Me(CH2)12CO− tetramethylene = 1,4-butanediyl −(CH2)4− 1,4-tetraphosphinediyl −(PH)4− tetrasiloxanylene = 1,7-tetrasiloxanediyl −SiH2(OSiH2)2OSiH2− tetrathio13 −SSSS− tetrazanediylidene = 1,4-tetrazanediylidene =N(NH)2N= tetrazanylene = 1,4-tetrazanediyl −(NH)4− 1-tetrazeno = 1-tetrazen-1-yl H2NNHN=N− thenoyl = (thienylcarbonyl) (C4H3S)CO− thenyl = (thienylmethyl) (C4H3S)CH2− thenylidene = (thienylmethylene) (C4H3S)CH= (thenyloxy) = (thienylmethoxy) (C4H3S)CH2O− thexyl = 1,1,2-trimethylpropyl Me2CHCMe2− thianaphthenyl = benzo[b]thienyl (C8H5S)− thiazolidyl = thiazolidinyl (C3H6NS)− thiazolinyl = (dihydrothiazolyl) (C3H4NS)− [(5-thiazolylcarbonyl)methyl] = [2-oxo-2-(5-thiazolyl)ethyl] 3 N (thionitroso) SN− thionyl = sulfinyl −SO− (thiophenacyl) = (2-phenyl-2-thioxoethyl) PhCSCH2− thiophene-yl = thienyl (C4H3S)− (thiophosphono) = (hydroxymercaptophosphinyl) (HO)(HS)P(O)− (thioseleneno)4 HSSe− (thiosulfeno)4 HSS− (thiosulfo)14 (HO2S2)− thioxo5 (see also epithio) S= (thioxoarsino) SAs− (thioxomethyl) (see also carbonothioyl) S=CH− thiuram = (aminothioxomethyl) H2NCS− threonyl1 (2-amino-3-hydroxy-1-oxobutyl) MeCH(OH)CH(NH2)CO− 4-thujyl = [2-methyl-5-(1-methylethyl)bicyclo[3.1.0]hex-2-yl] (C10H17)− thymyl (from thymol) = [5-methyl-2-(1-methylethyl)phenyl] Me 6 1 trisiloxane-1,3,5-triyl = 1,3,5-trisiloxanetriyl −SiH(OSiH2−)2 trithio13 −SSS− trityl = (triphenylmethyl) Ph3C− tropanyl = (8-methyl-8-azabicyclo[3.2.1]octyl) (C8H14N)− tropoyl = (3-hydroxy-1-oxo-2-phenylpropyl) HOCH2CHPhCO− tryptophyl1 = [2-amino-3-(1H-indol-3-yl)-1-oxopropyl] (C8H6N)CH2CH(NH2)CO− tyrosyl1 = [2-amino-3-(4-hydroxyphenyl)-1-oxopropyl] 4−HOC6H4CH2CH(NH2)CO− undecanoyl = (1-oxoundecyl) Me(CH2)9CO− uramino = [(aminocarbonyl)amino] H2NCONH− ureido = [(aminocarbonyl)amino] H2NCONH− ureylene = (carbonyldiimino) −NHCONH− (ureylenediureylene) = [carbonylbis(2,1-hydrazinediylcarbonylimino)] −NHCONHNHCONHNHCONH− ursanyl (from ursane) (C30H51)− valeryl = (1-oxopentyl) BuCO− valyl1 = (2-amino-3-methyl-1-oxobutyl) Me2CHCH(NH2)CO− vanillal = [(4-hydroxy-3-methoxyphenyl)methylene] 4,3−HO(MeO)C6H3CH= vanilloyl = (4-hydroxy-3-methoxybenzoyl) 4,3−HO(MeO)C6H3CO− vanillyl = [(4-hydroxy-3-methoxyphenyl)methyl] 4,3−HO(MeO)C6H3CH2− vanillylidene = [(4-hydroxy-3-methoxyphenyl)methylene] 4,3−HO(MeO)C6H3CH= vanilmandeloyl = [2-hydroxy-2-(4-hydroxy-3methoxyphenyl)acetyl] 4,3−HO(MeO)C6H3CH(OH)CO− veratral = [(3,4-dimethoxyphenyl)methylene] 3,4−(MeO)2C6H3CH= veratroyl = (3,4-dimethoxybenzoyl) 3,4−(MeO)2C6H3CO− o-veratroyl = (2,3-dimethoxybenzoyl) 2,3−(MeO)2C6H3CO− veratryl = [(3,4-dimethoxyphenyl)methyl] 3,4−(MeO)2C6H3CH2− o-veratryl = [(2,3-dimethoxyphenyl)methyl] 2,3−(MeO)2C6H3CH2− veratrylidene = [(3,4-dimethoxyphenyl)methylene] 3,4−(MeO)2C6H3CH= vinyl = ethenyl H2C=CH− vinylene = 1,2-ethenediyl −CH=CH− vinylidene = ethenylidene H2C=C= xanthen-9-yl = 9H-xanthen-9-yl (C13H9O)− xanth-9-yl = 9H-xanthen-9-yl (C13H9O)− xenyl = [1,1′-biphenyl]-4-yl 4−PhC6H4− xylidino = [(dimethylphenyl)amino] Me2C6H3NH− xyloyl = (dimethylbenzoyl) Me2C6H3CO− xylyl = (dimethylphenyl) Me2C6H3− xylylene = [phenylenebis(methylene)] −CH2C6H4CH2− CHMe 2 thyronyl = [O-(4-hydroxyphenyl)tyrosyl]1 or [2amino-3-[4-(4-hydroxyphenoxy)phenyl]-1-oxopropyl] [4−(4−HOC6H4O)C6H4]CH2CH(NH2)CO− toloxy = (methylphenoxy) MeC6H4O− p-toluenesulfonamido = [[(4-methylphenyl)sulfonyl]amino] 4−MeC6H4SO2NH− toluidino = [(methylphenyl)amino] MeC6H4NH− toluoyl = (methylbenzoyl) MeC6H4CO− toluyl = (methylbenzoyl) MeC6H4CO− tolyl = (methylphenyl) MeC6H4− α-tolyl = (phenylmethyl) PhCH2− tolylene = (methylphenylene) −(MeC6H3)− α-tolylene = (phenylmethylene) PhCH= tosyl = [(4-methylphenyl)sulfonyl] 4−MeC6H4SO2− triazano = triazanyl H2NNHNH− 1-triazeno = 1-triazen-1-yl H2NN=N− s-triazin-2-yl = 1,3,5-triazin-2-yl N N N trichothecanyl (from trichothecane) (C15H25O)− tridecanoyl = (1-oxotridecyl) Me(CH2)11CO− (trimethylammonio) Me3N+− (trimethylarsonio) Me3As+− trimethylene = 1,3-propanediyl −(CH2)3− (1,3,3-trimethyl-2-norbornyl) = (1,3,3-trimethylbicyclo[2.2.1]hept-2-yl) (C10H17)− (trimethylphosphonio) Me3P+− triseleno13 −SeSeSe− trisilanylene = 1,3-trisilanediyl −(SiH2)3− N S 1 COCH2 thienyl (C4H3S)− (thienylthienyl) = [bithiophen]yl (C4H3S)(C4H2S)− thio9 (see also epithio and thioxo) −S− (thioacetonylidene) = (2-thioxopropylidene) MeCSCH= thioacetyl = (1-thioxoethyl) MeCS− (thioarsenoso) = (thioxoarsino) S=As− (thiobenzoyl) = (phenylthioxomethyl) PhCS− (thiocarbamoyl) = (aminothioxomethyl) H2NCS− thiocarbamyl = (aminothioxomethyl) H2NCS− (thiocarbonyl) = carbonothioyl7 −CS− (thiocarboxy)14 HOSC− thiocyanato NCS− thiocyano = thiocyanato NCS− (thioformyl) = (thioxomethyl) HCS− (thiohexanoyl) = (1-thioxohexyl) Me(CH2)4CS− thiohydroperoxy = sulfeno4 HOS− or (mercaptooxy)4 HSO− (thiohydroxy) = mercapto4 HS− NOTE: In addition to the following comments it must be understood that stereochemical information is not provided for systematically named natural-product radicals in the list above. For example, the phytyl radical is named as 3,7,11,15-tetramethyl-2-hexadecenyl. Because the total stereochemistry of a phytyl compound may be influenced by the presence of other chiral centers, it would be misleading to supply it with the radical name. 1 2 3 This prefix is used in peptide nomenclature. This prefix may be used in a generic sense, e.g., aldoxime. This prefix is only used as a multiplying radical and in structural repeating units of polymers. 4 This prefix is used only when unsubstituted. 5 This prefix is used when both free valencies are attached to the same atom. This prefix is used when the free valencies are attached to different atoms which are usually not otherwise connected. 7 This prefix is used as a multiplying radical or when both free valencies are attached to the same atom. 8 The prefix “cumyl” has been used in the recent literature to mean αcumyl. 9 This prefix is used when the free valencies are attached to different atoms which are not otherwise connected. 10 This prefix is used when the free valencies are attached to different atoms which are otherwise connected. 11 This prefix may be used in a generic sense, e.g., ketoxime. 12 This prefix is used only in structural repeating units of polymers. 13 This prefix is used to denote a series of chalcogen atoms in a chain or an indefinite structure. 14 This prefix is not used when the hydrogen atom has been substituted by another atom or group if a definite structure can be determined. 6 125 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 J. SELECTED BIBLIOGRAPHY OF NOMENCLATURE OF CHEMICAL SUBSTANCES ¶ 296 Introduction IUPAC, IUB, and IUBMB Nomenclature Rules and Recommendations Organic chemistry Biochemistry Inorganic chemistry Macromolecular chemistry Miscellaneous American Chemical Society Nomenclature Chemical Abstracts Service Index Nomenclature ¶ 295 296 297 298 299 300 301 American Chemical Society Committee History and Development of Chemical Nomenclature General Organic chemistry Biochemistry Inorganic chemistry Macromolecular chemistry Stereochemistry ¶ 302 303 304 305 306 307 308 295. Introduction. The development of systematic chemical nomenclature is shared by a number of organizations. In the United States the American Chemical Society (ACS) established a Committee on Nomenclature and Notation as early as 1886, followed in 1911 by the ACS Committee on Nomenclature, Spelling, and Pronunciation, now known as the ACS Committee on Nomenclature, Terminology and Symbols. In addition, subject nomenclature committees and subcommittees exist in several ACS divisions. Internationally, nomenclature commissions of the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Biochemistry and Molecular Biology (IUBMB)1 approve and publish detailed recommendations.2,3 Before becoming officially recommended nomenclature policy, a typical path for a proposal originating in the United States has been as follows: an idea (suggested by an author, editor, committee member, etc.) is submitted to a subcommittee of subject specialists, then to an ACS divisional committee, the ACS Committee on Nomenclature, and finally to the appropriate nomenclature commission of the International Union of Pure and Applied Chemistry. References to current nomenclature rules of IUPAC, IUB, IUBMB, and ACS are listed below. A selection of references to older, superseded rules and to significant proposals of individual authors is also included because of the occasional use of such nomenclature in current chemical literature, and the need in retrospective searching. These older references also provide a historical perspective illustrating the precedents on which modern chemical nomenclature are based. Additional nomenclature information may be obtained from Chemical Abstracts Service. IUPAC, IUB, and IUBMB Nomenclature Rules and Recommendations 296. Organic chemistry 1. International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry, A Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993, R. Panico, W. H. Powell, Jean-Claude Richer, eds., Blackwell Scientific Publications, Oxford, UK, 1993, 190 pp. (Includes revisions, both published and hitherto unpublished, to the 1979 edition of Nomenclature of Organic Chemistry (see item 2, below). “Corrections to A Guide to IUPAC Nomenclature of Organic Compounds (IUPAC Recommendations 1993)”, Pure Appl. Chem. 1999, 71, 1327-1330. 2. ——, Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, 1979 edition, J. Rigaudy and S. P. Klesney, eds., Pergamon Press, Oxford, UK, 1979, 559 pp. (Section A, Hydrocarbons; Section B, Fundamental Heterocyclic Systems; Section C, Characteristic Groups Containing C, H, O, N, Halogen, S, Se, and/or Te; Section D, Organic Compounds Containing Elements Which Are Not Exclusively C, H, O, N, Halogen, S, Se, and Te (Provisional Recommendations 1978); Section E, Stereochemistry (Recommendations 1974); Section F, General Principles for the Naming of Natural Products and Related Compounds (Provisional Recommendations 1975); Section H, Isotopically Modified Compounds (Approved Recommendations 1978). This edition contains changes from previous editions of various sections. The first edition of Sections A and B, known as the 1957 IUPAC Rules, was published in “Nomenclature of Organic Chemistry, 1957”, Butterworths Scientific Pub- 1Known as the International Union of Biochemistry (IUB) prior to 1992. 2K L. Loening, “International Cooperation on Scientific Nomenclature”, J. Chem. Doc. 1970, 10, 231-236; “Terminology Guidelines and Their Application in the International Union of Pure and Applied Chemistry” in International Co-operation in Terminology Work, M. Krommer-Benz and K. G. Saur, eds. Munich, 1986, pp. 92-116 (Infoterm Series 8). 3International Union of Pure and Applied Chemistry, “Guidelines for Drafting IUPAC Technical Reports and Recommendations (2002)” in IUPAC Handbook, 2002-2003, IUPAC, 2002, pp. 344-353; “Procedure for Publication of IUPAC Technical Reports and Recommendations”, ibid., pp. 341-343. lications, London, 1958, pp 3-70; this edition also appeared with comments in J. Am. Chem. Soc. 1960, 82, 5545-5574. (These sections first appeared as “Tentative Rules for Organic Nomenclature”, C. R. de la Conf. Union Int. Chim., Zurich, July 20-28, 1955, pp. 160-184.) A second edition of Sections A and B appeared in “Nomenclature of Organic Chemistry”, Butterworths, London, 1966, pp. 3-70. The first edition of Section C was published as “Nomenclature of Organic Chemistry, Section C”, Butterworths, London, 1965, 260 pp. and also appeared in Pure Appl. Chem. 1965, 11, 1-260. (Section C first appeared as a paperback edition only as “Tentative Rules for Nomenclature of Organic Chemistry, Section C”, Butterworths, London, 1962, 238 pp.). A third edition of Sections A and B and a second edition of Section C were published together as “Nomenclature of Organic Chemistry, Sections A, B, and C”, Butterworths, London, 1971, 337 pp. A summary of the changes that were made in Sections A, B, and C for the combined 1971 edition of these sections appears in J. Chem. Doc. 1972, 12, 132-138. An early version of Section D was published in IUPAC Inf. Bull. Append. No. 31, August, 1973. The contents of the first edition of Section E appeared in Pure Appl. Chem. 1976, 45, 11-30, previously published as tentative rules in IUPAC Inf. Bull. No. 35, June, 1969, pp. 36-80, and in J. Org. Chem. 1970, 35, 2849-2867. Section F appeared earlier in IUPAC Inf. Bull. Append. No. 53, December, 1976 and in Eur. J. Biochem. 1978, 86, 1-8. The contents of the first edition of Section H appeared in Pure Appl. Chem. 1979, 51, 353-380, published previously as provisional recommendations in IUPAC Inf. Bull. Append. No. 62, July, 1977, and in Eur. J. Biochem. 1978, 86, 9-25. 3. ——, “Revision of the Extended Hantzsch-Widman System of Nomenclature for Heteromonocycles (Recommendations 1982)”, Pure Appl. Chem. 1983, 55, 409-416. Published previously as provisional recommendations in Pure Appl. Chem. 1979, 51, 1995-2003. For WWW version by G. P. Moss see 4. ——, “Treatment of Variable Valence in Organic Nomenclature (Lambda Convention) (Recommendations 1983)”, Pure Appl. Chem. 1984, 56, 769-778. Published previously as provisional recommendations entitled “The Designation of Non-Standard Classical Valence Bonding in Organic Nomenclature” in Pure Appl. Chem. 1982, 54, 217-227. For WWW version by G. P. Moss see 5. ——, “Extension of Rules A-1.1 and A-2.5 Concerning Numerical Terms Used in Organic Chemical Nomenclature (Recommendations 1986)”, Pure Appl. Chem. 1986, 58, 1693-1696. Published previously as provisional recommendations in Pure Appl. Chem. 1983, 55, 1463-1466. 6. ——, “Nomenclature for Cyclic Organic Compounds with Contiguous Formal Double Bonds (The δ-Convention) (Recommendations 1988)”, Pure Appl. Chem. 1988, 60, 1395-1401. For WWW version by G. P. Moss see http:/ / 7. ——, “Revised Nomenclature for Radicals, Ions, Radical Ions, and Related Species (Recommendations 1993)”, Pure Appl. Chem. 1993, 65, 13571455. A revision of Subsection C-0.8 of the 1979 edition of Nomenclature of Organic Chemistry (See item 2, above). 8. International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Commission on Biochemical Nomenclature, “Nomenclature of Carotenoids (Rules Approved 1974)”, Pure Appl. Chem. 1975, 41, 405-431 (amendments: Biochemistry 1975, 14, 1803-1804). Published previously as tentative rules in Biochemistry 1971, 10, 4827-4837. (These publications supersede rules in J. Am. Chem. Soc. 1960, 82, 5583-5584.) 9. ——, “Rules for Cyclitol Nomenclature (Recommendations 1973)”. Biochem. J. 1976, 153, 25-31. Published previously as tentative rules in J. Biol. Chem. 1968, 243, 5809-5819. 10. International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry. Commission on Physical Organic Chemistry, “Glossary of Class Names of Organic Compounds and Reactive Intermediates Based on Structure (Recommendations 1995)”, Pure Appl. Chem. 1995, 67, 1307-1375. For WWW version by G. P. Moss see http:/ / 11. ——, “Basic Terminology of Stereochemistry (Recommendations 1996)”, Pure Appl. Chem. 1996, 68, 2193-2222. For WWW version by G. P. Moss see ¶ 296 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Carbohydrates 126 12. International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Physical Organic Chemistry, “Glossary of Terms Used in Physical Organic Chemistry (Recommendations 1994)”, Pure Appl. Chem. 1994, 66, 1077-1184. Published previously as Recommendations 1982 in Pure Appl. Chem. 1983, 55, 1281-1371 and as provisional recommendations in Pure Appl. Chem. 1979, 51, 1725-1801. For WWW version by G. P. Moss see 13. ——, “Names for Hydrogen Atoms, Ions, and Groups, and for Reactions Involving Them (Recommendations 1988)”, Pure Appl. Chem. 1988, 60, 1115-1116. 14. ——, “Nomenclature for Organic Chemical Transformations (Recommendations 1988)”, Pure Appl. Chem. 1989, 61, 725-768 (includes provisional recommendations previously published as “Nomenclature for Straightfor-ward Transformations” in Pure Appl. Chem. 1981, 53, 305-321). 15. International Union of Pure and Applied Chemistry. “Nomenclature and Terminology of Fullerenes: A Preliminary Survey”, Pure Appl. Chem. 1997, 69, 1411-1434. 16. International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry, “Nomenclature of Fused and Bridged Fused Ring Systems (IUPAC Recommendations 1998)”, Pure Appl. Chem. 1998, 70, 143-216. 17. ——, “Phane Nomenclature. Part I: Parent Phane Names (IUPAC Recommendations 1998)”, Pure Appl. Chem. 1998, 70, 1513-1545. 18. ——, “Extension and Revision of the von Baeyer System for Naming Polycyclic Compounds (Including Bicyclic Compounds) (IUPAC Recommendations 1999)”, Pure Appl. Chem. 1999, 71, 513-529. 19. ——, “Extension and Revision of the Nomenclature for Spiro Compounds (IUPAC Recommendations 1999)”, Pure Appl. Chem. 1999, 71, 531-558. 20. ——, “Revised Section F: Natural Products and Related Compounds (IUPAC Recommendations 1999)”, Pure Appl. Chem. 1999, 71, 587-643. Superseded Section F published first in 1976, and then in 1978 (see item 2, above). 21. International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Physical Organic Chemistry, “Glossary of Terms Used in Theoretical Organic Chemistry (IUPAC Recommendations 1999)”, Pure Appl. Chem. 1999, 71, 1919-1981. 22. International Union of Pure and Applied Chemistry. Organic and Biomolecular Chemistry Division. Commission on Nomenclature of Organic Chemistry, “Nomenclature for the C60−Ih and C70−D5h(6) Fullerenes (IUPAC Recommendations 2002)”, Pure Appl. Chem. 2002, 74, 629-695. 23. ——, “Phane Nomenclature. Part II: Modification of the Degree of Hydrogenation and Substitution Derivatives of Phane Parent Hydrides (IUPAC Recommendations 2002)”, Pure Appl. Chem. 2002, 74, 809-834. 297. Biochemistry 1. International Union of Biochemistry and Molecular Biology, Biochemical Nomenclature and Related Documents 1992, 2nd. ed., Portland Press, Ltd., London, 1993. A compendium of recommendations of IUPAC and IUB produced by the Commission on Biochemical Nomenclature (CBN), the Nomenclature Committee of IUB (NC-IUB), and the IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN), prepared by C. Liebecq for the Committee of Editors of Biochemical Journals (CEBJ). The compendium includes Sections E and F of the IUPAC Organic Rules (see ¶ 296, item 2); nomenclature recommendations given in items 8-9, ¶ 296 and items listed below, except for items 20, 22, 23, 24, 29, 38, 39 and 40. It includes only the tentative rules of item 5. Section H of the IUPAC Organic Rules and item 29 appear in the 1979 edition of the compendium published in 1978 by The Biochemical Society, London. Also included in the 1992 compendium are “Isotopically Labeled Compounds: Common Biochemical Practice”; “Isotopically Substituted Compounds”; “Names for Hydrogen Species” (see ¶ 296, item 13); and “Excerpts from Newsletters of the Nomenclature Committees of IUB”. 2. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Commission on Biochemical Nomenclature, “Nomenclature of Phosphorus-Containing Compounds of Biochemical Importance (Recommendations 1976)”, Eur. J. Biochem. 1977, 79, 1-9. 3. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Joint Commission on Biochemical Nomenclature, “Nomenclature of Tetrapyrroles (Recommendations 1986)”, Pure Appl. Chem. 1987, 59, 779-832. Replaces “Recommendations 1978”, Pure Appl. Chem. 1979, 51, 2251-2304 of which an amended version appears in Eur. J. Biochem. 1980, 108, 1-30 and an abbreviated version by P. Karlson in Hoppe-Seyler’s Z. Physiol. Chem. 1981, 362, vii-xii. 4. ——, “Nomenclature of Steroids (Recommendations 1989)”, Pure Appl. Chem. 1989, 61, 1783-1822. (corrections: Eur. J. Biochem. 1993, 213, 2). For WWW version by G. P. Moss see [Supersedes “Definitive Rules for Nomenclature of Steroids”, Pure Appl. Chem. 1972, 31, 283-322 (book form: Butterworths, London, 1972), previously published as tentative rules in Biochemistry 1969, 8, 2227-2242 (amendments. ibid. 1971, 10, 4994), both of which superceded the definitive rules in “Nomenclature of Organic Chemistry, 1957” Butterworths Scientific Publications, London, 1958, pp. 71-82 and J. Am. Chem. Soc. 1960, 82, 55775581, and in “Nomenclature of Organic Chemistry” Butterworths, London, 1966, pp. 71-81 (tentative rules for which appeared in C. R. de la Conf. Union Int. Chim., Zurich, July 20-8, 1955, pp. 190-207)]. 5. ——, “Nomenclature of Lignans and Neolignans (IUPAC Recommendations 2000)”, Pure Appl. Chem. 2000, 72, 1493-1523. 6. International Union of Pure and Applied Chemistry and International Union of Biochemistry and Molecular Biology. Joint Commission on Biochemical Nomenclature. “Nomenclature of Carbohydrates (Recommendations 1996)”, Pure Appl. Chem. 1996, 68(10), 1919-2008. For WWW version by G. P. Moss see [Supercedes “Tentative Rules for Carbohydrate Nomenclature, Pt. 1”, Biochemistry 1971, 10, 3983-4004 (errarta: ibid. 1971, 10, 4995)] (see also ¶ 302, item 14). 7. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Joint Commission on Biochemical Nomenclature, “Conformational Nomenclature for Five and Six-Membered Ring Forms of Monosaccharides and their Derivatives (Provisional Recommendations)”, Pure Appl. Chem. 1981, 53, 1901-1906. Published as “Recommendations 1980” in Eur. J. Biochem. 1980, 111, 295-298 (A preliminary version was publishedin J.Chem. Soc.,Chem.Commun.1973, 505-508.See ¶ 302, item18). 8. ——, “Nomenclature of Branched-Chain Monosaccharides (Provisional Recommendations)”, Pure Appl. Chem. 1982, 54, 211-215. Published as “Recommendations 1980” in Eur. J. Biochem. 1981, 119, 5-8 (corrections: ibid. 1982, 125, 1). 9. ——, “Nomenclature of Unsaturated Monosaccharides (Provisional Recommendations)”, Pure Appl. Chem. 1982, 54, 207-210. Published as “Recommendations 1980” in Eur. J. Biochem. 1981, 119, 1-3 (corrections: ibid. 1982, 125, 1). 10. ——, “Abbreviated Terminology of Oligosaccharide Chains, Provisional”, Pure Appl. Chem. 1982, 54, 1517-1522. Published as “Recommendations 1980” in J. Biol. Chem. 1982, 257, 3347-3351. 11. ——, “Polysaccharide Nomenclature (Provisional)”, Pure Appl. Chem. 1982, 54, 1523-1526. Published as “Recommendations 1980” in J. Biol. Chem. 1982, 257, 3352-3354. 12. ——, “Symbols for Specifying the Conformation of Polysaccharide Chains (Provisional)”, Pure Appl. Chem. 1983, 55, 1269-1272 and as “Recommendations 1981,” in Eur. J. Biochem. 1983, 131, 5-7. 13. International Union of Biochemistry. Nomenclature Committee, “Numbering of Atoms in myo-Inositol (Recommendations 1988)”, Biochem. J. 1989, 258, 1-2. Amino Acids, Peptides, Proteins, and Nucleic Acids 14. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Commission on Biochemical Nomenclature, “Abbreviated Nomenclature of Synthetic Polypeptides (Polymerized Amino Acids) (Revised Rules)”, Pure Appl. Chem. 1973, 33, 437-444. Published previously as revised recommendations in Biochemistry 1972, 11, 942-944. 15. ——, “Abbreviations and Symbols for Nucleic Acids, Polynucleotides and their Constituents (Rules Approved 1974)”, Pure Appl. Chem. 1974, 40, 277-290. Published previously as revised rules in Biochemistry 1970, 9, 40224027. 16. ——, “Abbreviations and Symbols for Description of Conformation of Polypeptide Chains (Rules Approved 1974)”, Pure Appl. Chem. 1974, 40, 291308. Published previously as tentative rules in IUPAC Inf. Bull. Append. No. 10, February, 1971 and as “Tentative Rules (1969)” in Eur. J. Biochem. 1970, 17, 193-201. 17. ——, “Nomenclature of Peptide Hormones (Recommendations 1974)”, Biochemistry 1975, 14, 2559-2560. 18. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Joint Commission on Biochemical Nomenclature. “Nomenclature and Symbolism for Amino Acids and Peptides (Recommendations 1983),” Pure Appl. Chem. 1984, 56, 595-624 (corrections: Eur. J. Biochem. 1993, 213, 2). A combination and revision of four previously published recommendations: (a) “Nomenclature of α-Amino Acids (Recommendations 1974)”, Biochemistry 1975, 14, 449-462; published previously as provisional recommendations in IUPAC Inf. Bull. Append. No. 46, September 1975 (these publications supersede rules published in J. Am. Chem. Soc. 1960, 82, 5575-5577); (b) “Symbols for Amino Acid Derivatives and Peptides (Rules Approved 1974)”, Pure Appl. Chem. 1974, 40, 315-331; published previously as recommendations in Biochemistry 1972, 11, 1726-1732; (c) “Naming Synthetic Modifications of Natural Peptides (Definitive Rules)”, Pure Appl. Chem. 1972, 31, 647-653; published previously as tentative rules in Biochemistry 1967, 6, 362-364; (d) “A One-Letter Notation for Amino Acid Sequences (Definitive Rules)”, Pure Appl. Chem. 1972, 31, 639-645; published previously as tentative rules in Biochemistry 1968, 7, 2703-2715. For WWW version by G. P. Moss see 19. ——, “Abbreviations and Symbols for the Description of Conformations of Polynucleotide Chains (Provisional)”, Pure Appl. Chem. 1983, 55, 1273-1280; appeared also as “Recommendations 1982” in Eur. J. Biochem. 1983, 131, 9-15. 20. ——, “Nomenclature of Glycoproteins, Glycopeptides, and Peptidoglycans (Recommendations 1985)”, Pure Appl. Chem. 1988, 60, 1389-1394 (corrections: Eur. J. Biochem. 1989, 185, 485). 21. International Union of Biochemistry. Nomenclature Committee, “Nomenclature of Iron-Sulfur Proteins (Recommendations 1978)”, Eur. J. Biochem. 1979, 93, 427-430 (corrections: ibid. 1979, 95, 369 and 1979, 102, 315). Published previously as recommendations in Biochemistry 1973, 12, 3582-3583. 22. ——, “Nomenclature for Incompletely Specified Bases in Nucleic Acid Sequences (Recommendations 1984)”, Eur. J. Biochem. 1985, 150, 1-5 (corrections: ibid. 1986, 157, 1). 127 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Miscellaneous ¶ 298 23. ——, “Nomenclature of Electron-Transfer Proteins (Recommendations 1989)”, Eur. J. Biochem. 1991, 200, 599-611 (corrections: Eur. J. Biochem. 1993, 213, 2-3). 24. ——, “A Nomenclature of Junctions and Branchpoints in Nucleic Acids”, Eur. J. Biochem. 1995, 230, 1-2. 25. International Union of Pure and Applied Chemistry. IUPAC-IUBMBIUPAB Inter-Union Task Group on the Standardization of Data Bases of Protein and Nucleic Acid Structures by NMR Spectroscopy, “Recommendations for the Presentation of NMR Structures of Proteins and Nucleic Acids (IUPAC Recommendations 1998)”, Pure Appl. Chem. 1998, 70, 117-142. 41. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Commission on Biochemical Nomenclature, “Abbreviations and Symbols for Chemical Names of Special Interest in Biological Chemistry (Revised Tentative Rules 1965)”, Biochemistry 1966, 5, 1445-1453. 42. ——, “Abbreviations and Symbols”, Eur. J. Biochem. 1977, 74, 1-5. 43. International Union of Nutritional Sciences. Committee 1/ I. Nomenclature, “Generic Descriptors and Trivial Names for Vitamins and Related Compounds (Recommendations 1976)”, Nutrition Absts. and Revs., Series A: Human and Experimental 1978, 48, 831-835. 298. Inorganic chemistry 1. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division. Commission on the Nomenclature of Inorganic Chemistry, Nomenclature of Inorganic Chemistry Recommendations 1990, G. J. Leigh, ed., Blackwell Scientific Publications, Oxford, UK, 1990, 289 pp. These recommendations revise and extend the 2nd ed., “Nomenclature of Inorganic Chemistry, 1970”, Butterworths, London, 1971, 110 pp., which also appeared in Pure Appl. Chem. 1971, 28, 1-110, and the 1st ed., “Nomenclature of Inorganic Chemistry” (1957 Report of the Commission on the Nomenclature of Inorganic Chemistry), Butterworths Scientific Publications, London, 1958, 93 pp. (in French and English); the latter also appeared with comments in J. Am. Chem. Soc. 1960, 82, 5523-5544. The 1970 edition incorporated “Tentative Proposals for Nomenclature of Absolute Configurations Concerned with Six-Coordinated Complexes Based on the Octahedron”, Inorg. Chem. 1970, 9, 1-5; π-Complexes (Tentative), IUPAC Inf. Bull. No. 35, June, 1969, pp. 31-35; and Isoand Heteropolyanions (Rules 5.1 and 5.2, Tentative), IUPAC Inf. Bull. No. 35, June, 1969, pp. 22-27. 2. ——, “Nomenclature of Inorganic Boron Compounds”, Pure Appl. Chem. 1972, 30, 681-710 (see also ¶ 302, item 16). 3. ——, How to Name an Inorganic Substance. A Guide to the Use of Nomenclature of Inorganic Chemistry: Definitive Rules, 1970, Pergamon Press, New York, 1977, 36 pp. 4. ——, “Nomenclature of Inorganic Chemistry: II.2. The Nomenclature of Hydrides of Nitrogen and Derived Cations, Anions, and Ligands (Recommendations 1981)”, Pure Appl. Chem. 1982, 54, 2545-2552. Published previously as provisional recommendations in IUPAC Inf. Bull. 1978, (2), 151-160. 5. ——, “Recommendations for the Naming of Elements of Atomic Numbers Greater than 100 (Definitive)”, Pure Appl. Chem. 1979, 51, 381-384. Previously published as “Recommendations for the Naming of Elements of Atomic Numbers Greater Than 105 (Provisional)” in IUPAC Inf. Bull. Append. No. 55, December, 1976. 6. ——, “Nomenclature of Inorganic Chemistry: II.1. Isotopically Modified Compounds (Recommendations 1981)”, Pure Appl. Chem. 1981, 53, 1887-1900. Previously published as provisional recommendations in Pure Appl. Chem. 1979, 51, 1981-1994. 7. ——, “Nomenclature of Polyanions, Recommendations 1987”, Pure Appl. Chem. 1987, 59, 1529-1548. 8. ——, “Names and Symbols of Transfermium Elements (IUPAC Recommendations 1997)”, Pure Appl. Chem. 1997, 69, 2471-2473. Superseded “Names and Symbols of Transfermium Elements (Recommendations 1994)”, Pure Appl. Chem. 1994, 66, 2419-2421 (subsequently reclassified by the IUPAC Bureau as provisional in August, 1995). See K. I. Zamaraev, “IUPAC Recommendations on Names and Symbols of Transfermium Elements”, Chem. Int. 1996, 18(1), 34. 9. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division, “New Notations in the Periodic Table”, Pure Appl. Chem. 1988, 60, 431-436. 10. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division, Commission on High Temperature and Solid State Chemistry, “Nomenclature and Terminology of Graphite Intercalation Compounds (Recommendations 1994)”, Pure Appl. Chem. 1994, 66, 1893-1901. 11. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division. Working Party on IUPAC Glossary of Terms Used in Bioinorganic Chemistry, “Glossary of Terms Used in Bioinorganic Chemistry (IUPAC Recommendations 1997)”, Pure Appl. Chem. 1997, 60, 1251-1303. 12. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division. Commission on Nomenclature of Inorganic Chemistry, “Nomenclature of Inorganic Chains and Ring Compounds (IUPAC Recommendations 1997)”, Pure Appl. Chem. 1997, 69, 1659-1692. 13. ——, “Nomenclature of Organometallic Compounds of the Transition Elements (IUPAC Recommendations 1999)”, Pure Appl. Chem. 1999, 71, 1557-1585. 14. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division, Commission on High Temperature Materials and Solid State Chemistry, “Terminology for Compounds in the Si-Al-O-N System (IUPAC Recommendations 1999)”, Pure Appl. Chem. 1999, 71, 1765-1769. 15. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division. Commission on Nomenclature of Inorganic Chemistry, “Names for Inorganic Radicals (IUPAC Recommendations 1999)”, Pure Appl. Chem. 2000, 72, 437-446. 16. ——, “Names for Muonium and Hydrogen Atoms and Their Ions (IUPAC Recommendations 2001)”, Pure Appl. Chem. 2001, 73, 377-380. Enzymes 26. International Union of Biochemistry and Molecular Biology Nomenclature Committee, Enzyme Nomenclature, 1992, Academic Press, Orlando, Florida, 1992, 862 pp; Supplements 1, 2, 3, 4, and 5. Corrections and Additions, Eur. J. Biochem. 1994, 223, 1-5; 1995, 232, 1-6; 1996, 237, 1-5; 1997, 250, 1-6; 1999, 264, 610-650. (This edition includes corrections and additions to “Enzyme Nomenclature, 1984”, published as three supplements in Eur. J. Biochem. 1986, 157, 1-26; 1989, 179, 489-533; 1990, 187, 263-281; the 1984 edition updated the 1978 edition by including corrections and additions published as four supplements in Eur. J. Biochem. 1980, 104, 1-4; 1981, 116, 423435; 1982, 125, 1-13; 1983, 131, 461-472.) 27. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Commission on Biochemical Nomenclature, “The Nomenclature of Multiple Forms of Enzymes (Recommendations 1976)”, Eur. J. Biochem. 1978, 82, 1-3. Published previously as “Rules Approved 1974” in Pure Appl. Chem. 1974, 40, 309-314. 28. International Union of Biochemistry. Nomenclature Committee, “Symbolism and Terminology in Enzyme Kinetics (Recommendations 1981)”, Eur. J. Biochem. 1982, 128, 281-291 (corrections: Eur. J. Biochem. 1993, 213, 1). 29. ——, “Nomenclature for Multienzymes (Recommendations 1989)”, Eur. J. Biochem. 1989, 185, 485-486 (supercedes “Multienzyme Proteins” in Trends. Biochem. Sci. 1979, 4, N275). Lipids, Vitamins, Coenzymes, and Related Compounds 30. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Commission on Biochemical Nomenclature, “The Nomenclature of Lipids (Recommendations 1976)”, Eur. J. Biochem. 1977, 79, 11-21. Previously published as recommendations in J. Biol. Chem. 1967, 242, 4845-4849 (amendments: ibid. 1970, 245, 1511). 31. ——, “Trivial Names of Miscellaneous Compounds of Importance in Biochemistry (Tentative Rules)”, J. Biol. Chem. 1966, 241, 2987-2988. (Supersedes “Definitive Rules for the Nomenclature of the Vitamins”, J. Am. Chem. Soc. 1960, 82, 5581-5583.) 32. ——, “Nomenclature of Quinones with Isoprenoid Side Chains (Recommendations 1973)”, Eur. J. Biochem. 1975, 53, 15-18. Published previously as tentative rules in J. Biol. Chem. 1966, 241, 2989-2991. (Supersedes Rule V4 in J. Am. Chem. Soc. 1960, 82, 5581-5583.) 33. ——, “Nomenclature and Symbols for Folic Acid and Related Compounds (Recommendations 1986)”, Pure Appl. Chem. 1987, 59, 833-836. Published as “Tentative Rules” in J. Biol. Chem. 1966, 241, 2991-2992 which superseded Rule V-13 in J. Am. Chem. Soc. 1960, 82, 5581-5583. 34. ——, “Nomenclature of Corrinoids (Rules Approved 1975)”, Pure Appl. Chem. 1976, 48, 495-502. Published previously as recommendations in Biochemistry 1974, 13, 1555-1560 and as tentative rules in J. Biol. Chem. 1966, 241, 2992-2994. (Supersedes Rule V-15 in J. Am. Chem. Soc. 1960, 82, 55815583; tentative rules for which appeared in “Nomenclature of Organic Chemistry, 1957”, Butterworths Scientific Publications, London, 1958, pp. 83-87.) 35. ——, “Nomenclature for Vitamins B6 and Related Compounds (Recommendations 1973)”, Biochemistry 1974, 13, 1056-1058. Published previously as tentative rules in Biochemistry 1970, 9, 4019-4021. (Supersedes Section M-7 in J. Biol. Chem. 1966, 241, 2987-2988; see item 29 above.) 36. International Union of Pure and Applied Chemistry and International Union of Biochemistry. Joint Commission on Biochemical Nomenclature, “Nomenclature of Tocopherols and Related Compounds (Recommendations 1981)”, Pure Appl. Chem. 1982, 54, 1507-1510 and in Eur. J. Biochem. 1982, 123, 473-475. Published previously as “Recommendations 1973” in Eur. J. Biochem. 1974, 46, 217-219 and as provisional recommendations in IUPAC Inf. Bull. Append. No. 47, September, 1975. (Supersedes Section M-3 in J. Biol. Chem. 1966, 241, 2987-2988; see item 29 above.) 37. ——, “Nomenclature of Vitamin D (Provisional)”, Pure Appl. Chem. 1982, 54, 1511-1516. Published as “Recommendations 1981” in Eur. J. Biochem. 1982, 124, 223-227. 38. ——, “Nomenclature of Retinoids (Provisional)”, Pure Appl. Chem. 1983, 55, 721-726. Published as “Recommendations 1981” in Eur. J. Biochem. 1982, 129, 1-5. 39. ——, “Nomenclature of Prenols (Recommendations 1986)”, Pure Appl. Chem. 1987, 59, 683-689. 40. ——, “Nomenclature of Glycolipids (IUPAC Recommendations 1997)”, Pure Appl. Chem. 1997, 69, 2475-2487; Carbohydr. Res. 1998, 312, 167-175; Eur. J. Biochem. 1998, 257, 293-298; Glycoconjugate J. 1999, 16, 16; J. Mol. Biol. 1999 286, 963-970; Adv. Carbohydr. Chem. Biochem. 2000, 55, 311-326. Superseded the glycolipid section in the 1976 Recommendations on lipid nomenclature (see item 30, above). ¶ 298 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 128 17. ——, Nomenclature of Inorganic Chemistry II: Recommendations 2000, J. A. McCleverty and N. G. Connelly, eds., Royal Society of Chemistry, Oxford, UK, 2001, 130 pp. 18. ——, “Naming of New Elements (IUPAC Recommendations 2002)”, Pure Appl. Chem. 2002, 74, 787-791. 19. International Union of Pure and Applied Chemistry. Chemistry and Human Health Division. Clinical Chemistry Section. Commission on Toxicology, “ ′Heavy Metals′ - A Meaningless Term? (IUPAC Technical Report)”, Pure Appl. Chem. 2002, 74, 793-807. 20. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division. Commission on Nomenclature of Inorganic Chemistry, "On the Claims for Discovery of Elements 110, 111, 112, 114, 116, and 118 (IUPAC Technical Report)", Pure Appl. Chem. 2003, 75, 1601-1611. 21. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division, “Name and Symbol of the Element with Atomic Number 110 (IUPAC Recommendations 2003)”, Pure Appl. Chem. 2003, 75, 1613-1615. 299. Macromolecular chemistry 1. International Union of Pure and Applied Chemistry. Physical Chemistry Division. Commission on Macromolecules. Subcommission on Nomenclature, “Report on Nomenclature in the Field of Macromolecules (1951)”, J. Polym. Sci. 1952, 8, 257-277 [modifications and additions (tentative): J. Polym. Sci., Part B: Polym. Lett., 1968, 6, 257-260]. 2. ——, “Report on Nomenclature Dealing with Steric Regularity in High Polymers”, Pure Appl. Chem. 1966, 12, 645-656 (Authors often cited as M. L. Huggins, G. Natta, V. Desreux, and H. Mark); published previously as a preliminary version in J. Polym. Sci. 1962, 56, 153-161. 3. International Union of Pure and Applied Chemistry. Division of Applied Chemistry. Plastics and High Polymers Section, “Recommendations for Abbreviations of Terms Relating to Plastics and Elastomers”, Pure Appl. Chem. 1969, 18, 583-589. 4. International Union of Pure and Applied Chemistry. Macromolecular Division. Commission on Macromolecular Nomenclature, Compendium of Macromolecular Nomenclature, Blackwell Scientific Publications, Oxford, UK, 1991, 171 pp. (a collection of the recommendations given as items 5-12 and 18 below). For a bibliography of translations of this compendium prepared by W. V. Metanomski see purp.html 5. ——, “Nomenclature of Regular Single-Strand Organic Polymers (Rules Approved 1975)”, Pure Appl. Chem. 1976, 48, 373-385. Published previously as provisional recommendations in Macromolecules 1973, 6, 149-158 and in IUPAC Inf. Bull. Append. No. 29, November, 1972 (see also ¶ 302, item 15). Superseded by item 18, below. 6. ——, “Glossary of Basic Terms in Polymer Science (Recommendations 1996)”, Pure Appl. Chem. 1996, 68, 2287-2311. Supercedes “Basic Definitions of Terms Relating to Polymers (1974)”, Pure Appl. Chem. 1974, 40, 477-491, and “Basic Definitions Relating to Polymers”, IUPAC Inf. Bul. Append. No. 13, February 1971. 7. ——, “Stereochemical Definitions and Notations Relating to Polymers (Recommendations 1980)”, Pure Appl. Chem. 1981, 53, 733-752. Published previously as provisional recommendations in Pure Appl. Chem. 1979, 51, 1101-1121. 8. ——, “Source-Based Nomenclature for Copolymers (Recommendations 1985)”, Pure Appl. Chem. 1985, 57, 1427-1440. 9. —, “Use of Abbreviations for Names of Polymeric Substances (Recommendations, 1986)”, Pure Appl. Chem. 1987, 59, 691-693. (Supersedes “List of Standard Abbreviations (Symbols) for Synthetic Polymers and Polymer Materials 1974” Pure Appl. Chem. 1974, 40, 473-476 and “List of Abbreviations for Synthetic Polymers and Polymer Materials”, IUPAC Inf. Bull. Append. No. 12, February, 1971). 10. ——, “A Classification of Linear Single-Strand Polymers (Recommendations 1988)”, Pure Appl. Chem. 1989, 61, 243-254. 11. ——, “Definitions of Terms Relating to Individual Macromolecules, Their Assemblies, and Dilute Polymer Solutions (Recommendations 1988)”, Pure Appl. Chem. 1989, 61, 211-241. 12. ——, “Definition of Terms Relating to Crystalline Polymers (Recommendations 1988)”, Pure Appl. Chem. 1989, 61, 769-785. 13. ——, “Nomenclature of Regular Double-Strand (Ladder or Spiro) Organic Polymers (Recommendations 1993)”, Pure Appl. Chem. 1993, 65, 1561-1580. 14. ——, “Graphic Representations (Chemical Formulae) of Macromolecules (Recommendations 1994)”, Pure Appl. Chem. 1994, 66, 2469-2482. 15. ——, “Structure-Based Nomenclature for Irregular Single-Strand Organic Polymers (Recommendations 1994)”, Pure Appl. Chem. 1994, 66, 873-889 (Erratum: Pure Appl. Chem. 1994, 66 (9), insert). 16. ——, “Source-Based Nomenclature for Non-Linear Macromolecules and Macromolecular Assemblies (IUPAC Recommendations 1997)”, Pure Appl. Chem. 1997, 69, 2511-2521; in Polymer Networks, R. F. T. Stepto, ed., Blackie Academic, London, 1998, pp. 316-328. 17. ——, "Generic Source-Based Nomenclature for Polymers (IUPAC Recommendations 2001)", Pure Appl. Chem. 2001, 73, 1511-1519. Errata, Pure Appl. Chem. 2002, 74, 2002. 18. ——, "Nomenclature of Regular Single-Strand Organic Polymers" (IUPAC Recommendations 2002)", Pure Appl. Chem. 2002, 74, 1921-1956. Superseded item 5, above. 19. International Union of Pure and Applied Chemistry. Macromolecular Division. Commission on Macromolecular Nomenclature and Inorganic Chemistry Division. Commission on Nomenclature of Inorganic Chemistry, “Nomenclature for Regular Single-Strand and Quasi-Single-Strand Inorganic and Coordination Polymers (Recommendations 1984)”, Pure Appl. Chem. 1985, 57, 149-168. Published previously as provisional recommendations in Pure Appl. Chem. 1981, 53, 2283-2302. 300. Miscellaneous 1. International Union of Pure and Applied Chemistry. Interdivisional Committee on Nomenclature and Symbols, “Use of Abbreviations in the Chemical Literature (Recommendations 1979)”, Pure Appl. Chem. 1980, 52, 2229-2232. Previously published as provisional recommendations jointly with the Physical Chemistry Division Commission on Molecular Structure and Spectroscopy in IUPAC Inf. Bull. Append. No. 58, July, 1977 2. International Union of Pure and Applied Chemistry. Analytical Chemistry Division, Compendium of Analytical Nomenclature, Definitive Rules 1997, 3rd ed., Blackwell Science, Oxford, UK, 1998, 840 pp. Superseded Compendium of Analytical Nomenclature, Definitive Rules 1987, 2nd ed., Blackwell Scientific Publications, Oxford, UK, 1978, 279 pp. The 1977 Definitive Rules were published by Pergamon Press, Oxford, UK 1978, 223 pp. 3. International Union of Pure and Applied Chemistry. Analytical Chemistry Division. Commission on Analytical Nomenclature, “Guide to Trivial Names, Trade Names, and Synonyms for Substances Used in Analytical Nomenclature”, Pure Appl. Chem. 1978, 50, 339-370. Previously published as provisional recommendations under the title “List of Trivial Names and Synonyms (for Substances Used in Analytical Chemistry)” in IUPAC Inf. Bull. Append. No. 45, September, 1975. 4. International Union of Pure and Applied Chemistry. Physical Chemistry Division. Commission on Symbols, Terminology and Units, Quantities, Units, and Symbols in Physical Chemistry, 2nd. ed., Blackwell Scientific Publications, Oxford, UK, 1993, 166 pp. [An abbreviated list, 4 pp. A4 laminated card, is published by Blackwell Scientific Publications, Oxford, 1993]. This replaces the 1988 edition which in turn replaced “Manual of Symbols and Terminology for Physicochemical Quantities and Units”, Pure Appl. Chem. 1979, 51, 1-41. A 1973 edition was published by Butterworths, London, 1975 and a 1969 edition appeared in Pure Appl. Chem. 1970, 21, 1-44. (Supersedes rules in J. Am. Chem. Soc. 1960, 82, 5517-5522.) 5. International Union of Pure and Applied Chemistry. Physical Chemistry Division. Commission on Colloid and Surface Chemistry, “Chemical Nomenclature and Formulation of Compositions of Synthetic and Natural Zeolites (Definitive)”, Pure Appl. Chem. 1979, 51, 1091-1100. Previously published as provisional recommendations jointly with the Inorganic Chemistry Division Commission on Nomenclature of Inorganic Chemistry in IUPAC Inf. Bull. Append. No. 41, January, 1975. 6. International Union of Pure and Applied Chemistry; Compendium of Chemical Terminology (IUPAC Recommendations), 2nd ed., A. D. McNaught and A. Wilkinson, compliers, Blackwell Science, Oxford, UK, 1997, 336 pp. Superseded Compendium of Chemical Technology (IUPAC Recommendations), V. Gold, K. L. Loening, A. D. McNaught, and P. Sehmi, compilers, Blackwell Scientific Publications, Oxford, UK, 1987, 456 pp. 7. International Union of Pure and Applied Chemistry and International Union of Pure and Applied Physics. Transfermium Working Group, “Discovery of the Transfermium Elements (criteria that must be satisfied for the discovery of a new chemical element to be recognized)”, Part I, Pure Appl. Chem. 1991, 63, 879-886; Part II: Introduction to Discovery Profiles; Part III: Discovery Profiles of the Transfermium Elements, Pure Appl. Chem. 1993, 65, 17571814. [All three parts have been published together in Prog. Part. Nucl. Phys. 1992, 29, 453-530.] “Responses on the Report ‘Discovery of the Transfermium Elements’ Invited by the Transfermium Working Groups from Lawrence Berkeley Laboratory, California, the Joint Institute for Nuclear Research, Dubna, and Gesellshaft für Schwerionenforschung, Darmstadt, and the Reply to the Responses by the Transfermium Working Group”, Pure Appl. Chem. 1993, 65, 1815-1824. 8. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division, Commission on Atomic Weights and Isotopic Abundances, “Atomic Weights of the Elements 2001 (IUPAC Technical Report)”, Pure Appl. Chem. 2003, 75, 1107-1122. Superseded “Atomic Weights of the Elements 1999”, Pure Appl. Chem. 2001, 73, 667-683; “Atomic Weights of the Elements 1997”, Pure Appl. Chem. 1997, 71, 1593-1607; “Atomic Weights of the Elements 1995”, Pure Appl. Chem. 1996, 68, 2339-2359; and “Atomic Weights of the Elements 1993”, Pure Appl. Chem. 1994, 66, 2423-2444. 9. International Union of Pure and Applied Chemistry; Clinical Chemistry Division and the International Federation of Clinical Chemistry (IFCC), Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences (Recommendations 1995), Blackwell Science, Oxford, UK, 1995, 304 pp. 10. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division. Commission on Atomic Weights and Isotopic Abundances, “History of the Recommended Atomic-Weight Values from 1882 to 1997: A Comparison of Differences from Current Values to the Estimated Uncertainties of Earlier Values”, Pure Appl. Chem. 1998, 70, 237-257. 11. International Union of Pure and Applied Chemistry, Principles of Chemical Nomenclature. A Guide to IUPAC Recommendations, G. J. Leigh, H. A. Favre, and W. V. Metanomski, G. J. Leigh, ed., Blackwell Science, Oxford, UK, 1998, 133 pp. 12. International Union of Pure and Applied Chemistry. Inorganic Chemistry Division, Commission on Atomic Weights and Isotopic Abundances, “Atomic Weights of the Elements. Review 2000 (IUPAC Technical Report)”, Pure Appl. Chem. 2003, 75, 683-799. 129 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 American Chemical Society Nomenclature ¶ 302 301. Chemical Abstracts Service Index Nomenclature Introductions to Subject Indexes and Name Selection Manuals 1. American Chemical Society. Chemical Abstracts Service, “The Naming and Indexing of Chemical Compounds from Chemical Abstracts” [a reprint of the Introduction to the Subject Index to Volume 56 (January-June, 1962)], Chemical Abstracts Service, Columbus, Ohio, 1962. A previous edition was reprinted from the Introduction to the 1945 Subject Index (Chemical Abstracts 1945, 39, 5867-5975) which was combined with revisions introduced in 1957 (Subject Index 1957, 51, 1R-28R). 2. ——, “Combined Introductions: Subject, Formula, Ring System, and HAIC Indexes to Volume 66, January-June, 1967”, Chemical Abstracts Service, Columbus, Ohio, 1968. 3. ——, Naming and Indexing of Chemical Compounds, 1969 edition, Chemical Abstracts Service, Columbus, Ohio, 1969. 4. ——, “Naming and Indexing of Chemical Substances for Chemical Abstracts during the Ninth Collective Period (1972-1976)” [a reprint of Section IV (Selection of Index Names for Chemical Substances) from the Volume 76 Index Guide], Chemical Abstracts Service, Columbus, Ohio, 1973. 5. ——, Chemical Substance Name Selection Manual for the Ninth Collective Period (1972-1976), Chemical Abstracts Service, Columbus, Ohio, 1973. 6. ——, “Selection of Index Names for Chemical Substances” in the Volume 76-85 Cumulative Index Guide (1972-1976), Chemical Abstracts Service, Columbus, Ohio, 1977, Appendix IV. 7. ——, “Naming and Indexing of Chemical Substances for Chemical Abstracts” [a reprint of Appendix IV (Selection of Index Names for Chemical Substances) from the 1977 Index Guide], Chemical Abstracts Service, Columbus, Ohio, 1978. 8. ——, Chemical Substance Name Selection Manual, 1978 edition, Chemical Abstracts Service, Columbus, Ohio, 1978. 9. ——, “Selection of Index Names for Chemical Substances” in the 1977-1981 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1982, Appendix IV. 10. ——, “Naming and Indexing of Chemical Substances for Chemical Abstracts” [a reprint of Appendix IV (Chemical Substance Index Names) from the 1982 Index Guide], Chemical Abstracts Service, Columbus, Ohio, 1982. 11. ——, Chemical Substance Name Selection Manual, 1982 edition, Chemical Abstracts Service, Columbus, Ohio, 1982. 12. ——, “Chemical Substance Index Names” in the 1984 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1984, Appendix IV. 13. ——, “Naming and Indexing of Chemical Substances for Chemical Abstracts” [a reprint of Appendix IV (Chemical Substance Index Names) from the 1985 Index Guide], Chemical Abstracts Service, Columbus, Ohio, 1985. 14. ——, “Chemical Substance Index Names”, in the 1982-1986 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1987, Appendix IV. 15. ——, “Naming and Indexing of Chemical Substances for Chemical Abstracts” [a reprint of Appendix IV (Chemical Substance Index Names) from the 1987 Index Guide], Chemical Abstracts Service, Columbus, Ohio 1987. 16. ——, “Chemical Substance Index Names”, Appendix IV in the 1989 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1989. 17. ——, “Chemical Substance Index Names”, Appendix IV in the 1990 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1990. 18. ——, “Chemical Substance Index Names”, in the 1987-1991 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1992, Appendix IV (also appears in the “12th Collective Index on CD-ROM, Index Guide Appendixes I-IV [a reprint of Appendixes I-IV from the Index Guide to the 12th Collective Index], Chemical Abstracts Service, Columbus, Ohio, 1993). 19. ——, “Naming and Indexing of Chemical Substances for Chemical Abstracts” [a reprint of Appendix IV (Chemical Substance Index Names) from the 1992 Index Guide], Chemical Abstracts Service, Columbus, Ohio, 1992. 20. ——, Chemical Substance Name Selection Manual, 1982 edition (Revised, 1989) Chemical Abstracts Service, Columbus, Ohio. 21. ——, “Chemical Substance Index Names”, Appendix IV in the 1994 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1994. 22. ——, “Chemical Substance Index Names” in the 1992-1996 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1997, Appendix IV. 23. ——, “Chemical Substance Index Names” in the 1997 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1997, Appendix IV. 24. ——, “Naming and Indexing of Chemical Substances for CHEMICAL ABSTRACTS” [A reprint of Appendix IV (Chemical Substance Index Names) from the CHEMICAL ABSTRACTS 1997 Index Guide], Chemical Abstracts Service, Columbus, Ohio, 1997. 25. ——, “Chemical Substance Index Names” in the 1999 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 1999, Appendix IV. 26. ——, “Chemical Substance Index Names” in the 1997-2001 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 2002, Appendix IV. 27. ——, “Chemical Substance Index Names” in the 2002 Index Guide, Chemical Abstracts Service, Columbus, Ohio, 2002, Appendix IV. Ring Nomenclature Handbooks 1. A. M. Patterson and L. T. Capell, The Ring Index, Rheinhold, New York, 1940, 661 pp. 2. A. M. Patterson, L. T. Capell, and D. F. Walker, The Ring Index, 2nd ed., American Chemical Society, Washington, D. C., 1960, 1425 pp.; Supplement 1, 1963, 371 pp.; Supplement 2, 1964, 515 pp.; Supplement 3, 1965, 581 pp.; “New Ring Systems from Chemical Abstracts Volumes 60-63”, Chemical Abstracts Service, Columbus, Ohio, 1967, 285 pp. 3. Parent Compound Handbook, American Chemical Society, Washington, D. C., 1977 (Annual supplements appeared through 1983). 4. Ring Systems Handbook, 1984 edition, Chemical Abstracts Service, Columbus, Ohio, 1984 (Six cumulative supplements were published, the last in November 1987). 5. Ring Systems Handbook, 1988 edition, Chemical Abstracts Service, Columbus, Ohio, 1988 (Eight cumulative supplements were published, the last in November, 1992). 6. Ring Systems Handbook, 1993 edition, Chemical Abstracts Service, Columbus, Ohio, 1993 (Eight cumulative supplements were published, the last in November 1997). 7. Ring Systems Handbook, 1998 edition, Chemical Abstracts Service, Columbus, Ohio, 1998 (Eight cumulative supplements were published, the last in November 2002). 8. Ring Systems Handbook, 2003 edition, Chemical Abstracts Service, Columbus, Ohio, 2003. Nomenclature Publications 1. A. M. Patterson, L. T. Capell, and D. F. Walker, The Ring Index, 2nd ed., American Chemical Society, Washington, D.C., 1960. Introduction. pp. ixxxvi; Suppl. 1, 1963, Introduction, pp. x-xiii. 2. J. E. Blackwood, C. L. Gladys, K. L. Loening, A. E. Petrarca, and J. E. Rush, “Unambiguous Specification of Stereoisomerism about a Double Bond”, J. Am. Chem. Soc. 1968, 90, 509-510. 3. J. E. Blackwood, C. L. Gladys, A. E. Petrarca, W. H. Powell, and J. E. Rush, “Unique and Unambiguous Specification of Stereoisomerism about a Double Bond in Nomenclature and Other Notation Systems”, J. Chem. Doc. 1968, 8, 30-32. 4. K. L. Loening, W. Metanomski, and W. H. Powell, “Indexing of Polymers in Chemical Abstracts”, J. Chem. Doc. 1969, 9, 248-251. 5. N. Donaldson, W. H. Powell, R. J. Rowlett, Jr., R. W. White, and K. Yorka, “Chemical Abstracts Index Names for Chemical Substances in the Ninth Collective Period (1972-76)”, J. Chem. Doc. 1974, 14, 3-15. 6. R. J. Rowlett, Jr. and F. A. Tate, “A Computer-Based System for Handling Chemical Nomenclature and Structural Representations”, J. Chem. Doc. 1972, 12, 125-128. 7. R. J. Rowlett, Jr. and D. W. Weisgerber, “Handling Commercial Product Names at Chemical Abstracts Service”, J. Chem. Doc. 1974, 14, 92-95. 8. J. E. Blackwood and P. M. Giles, Jr., “Chemical Abstracts Stereochemical Nomenclature of Organic Substances in the Ninth Collective Period (19721976)”, J. Chem. Inf. Comput. Sci. 1975, 15, 67-72. 9. M. F. Brown, B. R. Cook, and T. E. Sloan, “Stereochemical Notation in Coordination Chemistry. Mononuclear Complexes”, Inorg. Chem. 1975, 14, 1273-1278. 10. M. F. Brown, B. R. Cook, and T. E. Sloan, “Stereochemical Notation in Coordination Chemistry. Mononuclear Complexes of Coordination Numbers Seven, Eight, and Nine”, Inorg. Chem. 1978, 17, 1563-1568. 11. A. C. Isenberg, J. T. LeMasters, A. F. Maxwell, and G. G. Vander Stouw, “Procedures for Sorting Chemical Names for Chemical Abstracts’ Indexes”, J. Chem. Inf. Comput. Sci. 1985, 25(4), 410-412. 12. J. E. Blackwood, P. E. Blower, Jr., S. W. Layten, D. H. Lillie, A. H. Lipkus, J. P. Peer, C. Qian, L. M. Staggenborg, and C. E. Watson. “Chemical Abstracts Service Chemical Registry System. 13. Enhanced Handling of Stereochemistry”, J. Chem. Inf. Comput. Sci. 1991, 31, 204-212. 13. C. L. Gladys and A. L. Goodson, “Numbering of Interior Atoms in Fused Ring Systems”, J. Chem. Inf. Comput. Sci. 1991, 31, 523-526. 14. P. M. Giles, Jr. and W. V. Metanomski, “The History of Chemical Substance Nomenclature at Chemical Abstracts Service (CAS)” in Organic Chemistry: Its Language and its State of the Art, M. Volkan Kisakürek, ed., Verlag Helvetica Chemica Acta, Basel, 1993, pp. 173-196. 15. L. M. Staggenborg, “Stereochemistry in the CAS Registry File”, Spec. Publ. - R. Soc. Chem. 1993, 120, 89-112. (Recent Advances in Chemical Information II). 16. A. L. Goodson, C. L. Gladys, and D. E. Worst, “Numbering and Naming of Fullerenes by Chemical Abstracts Service”, J. Chem. Inf. Comput. Sci. 1995, 35, 969-978. 17. D. W. Weisgerber, “Chemical Abstracts Service Chemical Substance Index Nomenclature” in Chemical Nomenclature, K. J. Thurlow, ed., Kluwer Academic Publishers, Dordrecht, The Netherlands, 1998, pp. 66-102. 18. C. E. Carraher, Jr., “Chemical Abstracts Based Polymer Nomenclature”, J. Polym. Mater. 2000, 18, 1-6. 19. S. J. Teague, “Siloxanes and Silicones in the CAS Databases”, Polym. Prepr. 2001, 42(1), xviii-xxii. 302. American Chemical Society Committee 1. American Chemical Society, “Recommendations of the Nomenclature Committee of the Organic Division of the ACS to the Nomenclature Committee of the National Society”, J. Am. Chem. Soc. Proc. 1931, 40-41. 2. ——, “The Pronunciation of Chemical Words”, Ind. Eng. Chem., News Ed. 1934, 12, 202-205. ¶ 302 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 130 3. ——, “Nomenclature of the Hydrogen Isotopes and Their Compounds”, Ind. Eng. Chem., News Ed. 1935, 13, 200-201. 4. ——, “Report of the Committee for the Revision of the Nomenclature of Pectic Substances”, Chem. Eng. News 1944, 22, 105-106. 5. ——, “Nomenclature of Carotenoid Pigments”, Chem. Eng. News 1946, 24, 1235-1236. 6. ——, “The Naming of cis and trans Isomers of Hydrocarbons Containing Olefin Double Bonds”, Chem. Eng. News 1949, 27, 1303. 7. ——, “The Designation of ‘Extra’ Hydrogen in Naming Cyclic Compounds”, Chem. Eng. News 1949, 27, 1303. 8. ——, “The Naming of Geometric Isomers of Polyalkyl Monocycloalkanes”, Chem. Eng. News 1950, 28, 1842-1843. 9. ——, “The Report of the ACS Nomenclature, Spelling, and Pronunciation Committee for the First Half of 1952”, Chem. Eng. News 1952, 30, 4513-4526. A. “Arene and Arylene”, p. 4513. B. “Halogenated Derivatives of Hydrocarbons”, pp. 4513-4514. C. “The Use of ‘Per’ in Naming Halogenated Organic Compounds”, pp. 4514-4515. D. “The Use of ‘H’ to Designate the Positions of Hydrogens in Almost Completely Fluorinated Organic Compounds”, p. 4515. E. “Organic Compounds Containing Phosphorus”, pp. 4515-4522. F. “Organosilicon Compounds”, pp. 4517-4522. (These rules supersede the ACS 1946 rules which appeared in Chem. Eng. News 1946, 24, 1233-1234.) G. “Nomenclature of Natural Amino Acids and Related Substances”, pp. 4522-4526. (These rules were reprinted in J. Am. Chem. Soc. 1960, 82, 5575-5577. They replaced the 1947 ACS rules which appeared in Chem. Eng. News 1947, 25, 1364-1367. See also ¶ 297, item 16.) 10. ——, “A New General System for the Naming of Stereoisomers”, G. E. McCasland, included with the “Report of the Advisory Committee on Configurational Nomenclature”, July 14, 1953, H. B. Vickery, Chairman, to the Nomenclature Committee, Division of Organic Chemistry, American Chemical Society, Washington, D.C. 11. ——, “Addendum to Definitive Rules for the Nomenclature of Natural Amino Acids and Related Substances”, J. Org. Chem. 1963, 28, 291-293. (See also ¶ 297, item 16 and item 9G above). 12. ——, “A Proposed System of Nomenclature for Terpene Hydrocarbons”, Chem. Eng. News 1954, 32, 1795-1797. 13. ——, “Nomenclature for Terpene Hydrocarbons”, a report of the Nomenclature Committee of the Division of Organic Chemistry of the American Chemical Society, American Chemical Society, Washington, D.C., 1955, 98 pp. (Advances in Chemistry Series No. 14.) 14. ——, “Rules of Carbohydrate Nomenclature”, J. Org. Chem. 1963, 28, 281-291. (This report was the result of a cooperative effort by the Nomenclature Committee of the Division of Carbohydrate Chemistry of the American Chemical Society and a British Committee on Carbohydrate Nomenclature [a Subcommittee of the Publications Committee of the Chemical Society, London]. They are sometimes referred to as the “Anglo-American Rules” and were accepted by the Council of the American Chemical Society in 1962. They replaced the ACS 1953 rules which appeared in Chem. Eng. News 1953, 31, 1776-1782, which in turn replaced the ACS 1948 Carbohydrate Nomenclature Rules published in Chem. Eng. News 1948, 26, 1623-1629. These rules precede the tentative IUPAC carbohydrate rules, see ¶ 297, item 5.) 15. ——, “A Structure-Based Nomenclature for Linear Polymers”, Macromolecules 1968, 1, 193-198. These rules precede the IUPAC rules; see ¶ 299, item 5. 16. ——, “The Nomenclature of Boron Compounds”, Inorg. Chem. 1968, 7, 1945-1964. These rules precede the IUPAC rules; see ¶ 298, item 2. 17. ——, “ACS Committee on Nomenclature Recommendations”, J. Chem. Doc. 1973, 13, 45 (News and Notes) (On the use of the diagonal, the hyphen, and the dash in chemical names). 18. American Chemical Society. Division of Carbohydrate Chemistry. Nomenclature Committee and the British Carbohydrate Nomenclature Committee, “Rules for Conformational Nomenclature for Five- and Six-Membered Rings in Monosaccharides and Their Derivatives”, J. Chem. Soc., Chem. Commun. 1973, 505-508. These rules precede the IUPAC recommendations; see ¶ 297, item 6. 19. American Chemical Society. Division of Polymer Chemistry. Nomenclature Committee, “Abbreviations for Thermoplastics, Thermosets, Fiber, Elastomers, and Additives”, Polym. News 1983, 9, 101-110; 1985, 10, 169172. 20. J. A. Young, “Revised Nomenclature for Highly Fluorinated Organic Compounds”, J. Chem. Doc. 1974, 14, 98-100. 21. W. C. Fernelius and W. H. Powell, “Confusion in the Periodic Table of the Elements”, J. Chem. Educ. 1982, 59, 504-508. 22. K. L. Loening, “Recommended Format for the Periodic Table of the Elements”, J. Chem. Educ. 1984, 61, 136. 23. K. L. Loening, “Activities in the United States Relating to Chemical Terminology and Nomenclature”, TermNet News 1987, (18), 3-6. 24. B. P. Block, W. C. Fernelius, and W. H. Powell, Inorganic Chemical Nomenclature: Principles and Practice, American Chemical Society, Washington, D.C., 1990, 210 pp. History and Development of Chemical Nomenclature 303. General 1. E. J. Crane, “The Standardization of Chemical Nomenclature”, J. Chem. Educ. 1931, 8, 1335-1340. (Contains references.) 2. A. D. Mitchell, British Chemical Nomenclature, Edward Arnold & Co., London, 1948, 156 pp. 3. E. J. Crane, “Chemical Nomenclature in the United States” in Chemical Nomenclature, American Chemical Society, Washington, D.C., 1953, pp. 5564. (Advances in Chemistry Series No. 8.) 4. R. S. Cahn and A. D. Mitchell, “Chemical Nomenclature in Britain Today” in Chemical Nomenclature, American Chemical Society, Washington, D.C., 1953, pp. 49-54. (Advances in Chemistry Series No. 8.) 5. K. A. Jensen, “Problems of an International Chemical Nomenclature” in Chemical Nomenclature, American Chemical Society, Washington, D.C., 1953, pp. 38-48. (Advances in Chemistry Series No. 8.) 6. H. S. Nutting, “Nomenclature in Industry” in Chemical Nomenclature, American Chemical Society, Washington, D.C., 1953, pp. 95-98. (Advances in Chemistry Series No. 8.) 7. G. M. Dyson, “Development of Chemical Symbols and their Relation to Nomenclature” in Chemical Nomenclature, American Chemical Society, Washington, D.C., pp. 99-105. (Advances in Chemistry Series No. 8.) 8. J. W. Perry, “The Role of Terminology in Indexing, Classifying, and Coding” in Chemical Nomenclature, American Chemical Society, Washington, D.C., 1953, pp. 106-112. (Advances in Chemistry Series No. 8.) 9. A. M. Patterson, Words About Words, American Chemical Society, Washington, D.C., 1957, 86 pp. (A compilation of the column by A. M. Patterson which appeared in Chem. Eng. News 1951-1956.) 10. L. T. Capell, “Effect of Changes in Nomenclature on the Use of Indexes” in Searching the Chemical Literature, American Chemical Society, Washington, D.C., 1961, pp. 58-66. (Advances in Chemistry Series No. 30.) 11. J. D. Scott and K. L. Loening, “Inorganic-Organic Nomenclature”, J. Chem. Doc. 1964, 4, 66-69. 12. O. C. Dermer, G. Gorin, and K. L. Loening, “The Standardization of Chemical Language”, Int. J. Sociol. Lang. 1976, 11, 61-83. 13. R. S. Cahn and O. C. Dermer, Introduction to Chemical Nomenclature, 5th, ed., Butterworths, London, 1979, 200 pp. 14. K. L. Loening, “Nomenclature” in Kirk-Othmer Encyclopedia of Chemical Technology, 3rd ed., John Wiley & Sons, New York, Vol. 16, 1981, pp. 28-46; 2nd ed., Vol. 14, 1967, pp. 1-15. 15. R. Lees and A. F. Smith eds., Chemical Nomenclature Usage, Ellis Horwood, Ltd., Chichester, UK, 1983, 172 pp. 16. R. Fennell, History of IUPAC, 1919-1987, Blackwell Science, Oxford, UK, 1994 354 pp. 17. Council of Biology Editors. Style Manual Committee, Scientific Style and Format; CBE Manual for Authors, Editors, and Publishers. E. Huth, ed., 6th ed., Cambridge University Press, Cambridge, UK, 1995. 825 pp. 18. P. A. S. Smith, “Nomenclature” in Kirk-Othmer Encyclopedia of Chemical Technology, 4th ed., John Wiley & Sons, New York, Vol. 17, 1996, pp. 238-259. 19. K. J. Thurlow, ed., Chemical Nomenclature, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1998, 247 pp. 20. E. D. Godly, “The Need for Good Nomenclature” in Chemical Nomenclature, K. J. Thurlow, ed., Kluwer Academic Publishers, Dordrecht, The Netherlands, 1998, pp. 1-26. 21. S. S. Brown, History of IUPAC 1988-1999. Supplement to History of IUPAC 1919-1987, IUPAC, 2001, pp. 355-442 (Update of item 16, above). 22. J. Simon, “Authority and Authorship in the Method of Chemical Nomenclature”, Ambix 2002, 49, 206-226. 304. Organic chemistry Geneva Rules 1. A. Pictet, “Le Congres International de Geneve pour la Reforme de la Nomenclature Chimique”, Arch. Sci. Phys. Nat. 1892, [3] 27, 485-520. 2. M. Hanriot, “Congres de Nomenclature Chimique, Geneve 1892”, Bull. Soc. Chim. Paris Suppl. 1892, s. 3, 7, XIV-XXIV. 3. H. E. Armstrong, “The International Conference on Chemical Nomenclature”, Nature, 1892, 46, 56-58. 4. F. Tiemann, “Ueber die Beschluesse des Internationalen, in Genf von 19 bis 22 April 1892, versammelten Congresses zur Regelung der chemischen Nomenklatur”, Ber. Dtsch. Chem. Ges. 1893, 26, 1595-1631. Liege Rules 1. International Union of Chemistry. Commission on the Reform of the Nomenclature of Organic Chemistry, “Definitive Report, Liege Meeting, 1930”. (Translation with comments by A. M. Patterson, J. Am. Chem. Soc. 1933, 55, 3905-3925. Appeared also in English, J. Chem. Soc. 1931, 16071616.) 2. International Union of Chemistry. Commission on the Reform of the Nomenclature of Organic Chemistry, “Full Text of the New Organic Nomenclature Rules”. Reported by A. M. Patterson, Science 1938, 87, 215-216 (Rules 34 and 49 of the Liege Report are given in full). Amsterdam Rules 1. International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on the Nomenclature of Organic Chemistry, “Nomenclature of Organosilicon Compounds”, C. R. de la Quinzieme Conference, Amsterdam, 1949, 127-132. 131 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 ¶ 304 2. ——, “Changes and Additions to the Definitive Report [of the Liege Meeting]”, C. R. de la Quinzieme Conference, Amsterdam, 1949, 132-185. Proposals and Reviews 1. A. Hantzsch and J. H. Weber, Ber. Dtsch. Chem. Ges. 1887, 20, 31183132. 2. O. Widman, J. Prakt. Chem. 1888, 38, 185-201. 3. A. Baeyer, “Systematik und Nomenklatur Bicyclischer Kohlenwasserstoffe”, Ber. Dtsch. Chem. Ges. 1900, 33, 3771-3775. 4. E. Buchner und W. Weigand, “Bornylen und Diazoessigester [Nebst einer Nomenklatur Tricyclischer Kohlenstoff-Ringsysteme nach Adolf von Baeyer]”, Ber. Dtsch. Chem. Ges. 1913, 46, 2108-2117. 5. A. M. Patterson and C. E. Curran, “A System of Organic Nomenclature”, J. Am. Chem. Soc. 1917, 39, 1623-1638. 6. A. M. Patterson, “Proposed International Rules for Numbering Organic Ring Systems”, J. Am. Chem. Soc. 1925, 47, 543-561. 7. ——, “The Nomenclature of Parent Ring Systems”, J. Am. Chem. Soc. 1928, 50, 3074-3087. 8. ——, “The Nomenclature of Organic Compounds of Complex Function”, Rec. Trav. Chim. 1929, 48, 1012-1017. 9. P. E. Verkade, “La revision recente de la nomenclature des combinaisons organiques”, Rec. Trav. Chim. 1932, 51, 185-217. 10. A. M. Patterson and L. T. Capell, “The Ring Index”, Reinhold, New York, 1940, pp. 20-27. 11. F. Richter, “Basic Features of Nomenclature in Organic Chemistry” in Chemical Nomenclature, American Chemical Society, Washington, D.C., 1953, pp. 65-74. (Advances in Chemistry Series No. 8.) 12. P. E. Verkade, “Organic Chemical Nomenclature, Past, Present, and Future” in Chemical Nomenclature, American Chemical Society, Washington, D.C., 1953, pp. 75-82. (Advances in Chemistry Series No. 8.) 13. L. T. Capell and K. L. Loening, “Principles of Organic Nomenclature” in Treat. Anal. Chem., I. M. Kolthoff and P. J. Elving, eds., Interscience, New York, Vol. 11, 1965, Part II, Section B, pp. 1-44. 14. D. R. Eckroth, “Method for Manual Generation of Correct von Baeyer Names of Polycyclic Hydrocarbons”, J. Org. Chem. 1967, 32, 3362-3365. 15. A. D. McNaught, “The Nomenclature of Heterocycles” in Advances in Heterocyclic Chemistry, A. R. Katritzky and A. J. Boulton, eds., Academic Press, New York, 1976, Vol. 20, pp. 175-247. 16. A. Balaban and P. von Rague Schleyer, “Systematic Classification and Nomenclature of Diamond Hydrocarbons. I. Graph-Theoretical Enumeration of Polymantanes”, Tetrahedron 1978, 34, 3599-3609. 17. N. Lozac’h, A. L. Goodson, and W. H. Powell, “Nodal Nomenclature - General Principles”, Angew. Chem. 1979, 91, 951-964; Angew. Chem., Int. Ed. Engl. 1979, 18, 887-899. 18. A. L. Goodson, “Graph Based Chemical Nomenclature. 1. Historical Background and Discussion”, J. Chem. Inf. Comput. Sci. 1980, 20, 167-172; “2. Incorporation of Graph-Theoretical Principles into Taylor’s Nomenclature Proposal”, ibid. 1980, 20, 172-176. 19. K. L. Loening, “Hydrocarbons: Nomenclature” in Kirk-Othmer Encyclopedia of Chemical Technology, 3rd ed., John Wiley and Sons, New York, Vol. 12, 1980, pp. 892-900; 2nd ed., Vol. 11, 1966, pp. 288-293. 20. D. Eckroth, “Nitrogen’s Hydrido Oxo Acids”, J. Chem. Inf. Comput. Sci. 1983, 23, 157-159. 21. A. L. Goodson, “Application of Graph-Based Chemical Nomenclature to Theoretical and Preparative Chemistry,” Croat. Chem. Acta 1983, 56, 315-324. 22. N. Lozac’h and A. L. Goodson, “Nodal Nomenclature II - Specific Nomenclature for Parent Hydrides, Free Radicals, Ions, and Substituents”, Angew. Chem. 1984, 96, 1-15; Angew. Chem., Int. Ed. Engl. 1984, 23, 33-46. 23. A. D. McNaught and P. A. S. Smith, “Nomenclature of Heterocyclic Compounds” in Comprehensive Heterocyclic Chemistry, A. R. Katritzky and C. W. Rees, eds., Pergamon Press, Oxford, UK, 1984, pp. 7-45. 24. A. L. Goodson and N. Lozac’h, “Advantages of Nodal Nomenclature for Uniquely Identifying Atoms in Chemical Nomenclature”, Croat. Chem. Acta 1986, 59, 547-563. 25. W. V. Metanomski, “Unusual Names Assigned to Chemical Substances”, Chem. Int. 1987, 9, 211-215; Irish Chem. News 1988 (Spring), 31-34; Biochim. Clin. 1990, 14, 58-62. 26. A. L. 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Eliel, “Infelicitous Stereochemical Nomenclature”, Chirality 1997, 9, 428-430. 16. E. L. Eliel and M. B. Ramirez, “(-)-Quinic Acid: Configurational (Stereochemical) Descriptors”, Tetrahedron: Asymmetry 1997, 8, 3551-3554. 17. S. B. Elk, “Redefining the Terminology of Stereoisomerism To Produce a Mathematics-Based Taxonomy Paradigm”, THEOCHEM 1998, 431, 237-247. 18. J. Gal, “Problems of Stereochemical Nomenclature and Terminology. 1. The Homochiral Controversy. Its Nature and Origins, and a Proposed Solution”, Enantiomer 1998, 3, 263-273. 19. J. Michl and R. West, “Conformations of Linear Chains. Systematics and Suggestions for Nomenclature”, Acc. Chem. Res. 2000, 33, 821-823. 20. A. Berces, D. M. Whitfield, and T. Nukada, “Quantitative Description of Six-Membered Ring Conformations Following the IUPAC Conformational Nomenclature”, Tetrahedron 2001, 57, 477-491. 21. J. Caldwell and I. W. Wainer, “Stereochemistry: Definitions and a Note on Nomenclature”, Hum. Psychopharmacol. Clin. Exp. 2001, 16, S105-S107. 22. K. C. Nicolau, C. N. C. Boddy, and J. S. Siegel, “Does CIP Nomenclature Adequately Handle Molecules with Multiple Stereoelements? A Case Study of Vancomycin and Cognates”, Angew. Chem., Int. Ed. 2001, 40, 701-704. ¶ 308 Inorganic Compounds Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 136 1. W. Thewalt, K. A. Jensen, and C. E. Schaeffer, “A Nomenclature Symbolism for Chiral and Achiral Isomers of Bridged Inorganic Complexes”, Inorg. Chem. 1972, 11, 2129-2136. 2. T. E. Sloan and D. H. Busch, “Stereochemical Description and Notation for Coordination Systems” in Stereochemistry of Optically Active Transition Metal Compounds, B. E. Douglas and Y. Saito, eds., American Chemical Society, Washington, D.C., 1980, pp. 397-419. (ACS Symposium Series No. 119.) 3. T. E. Sloan, “Stereochemical Nomenclature and Notation in Inorganic Chemistry” in Topics in Inorganic and Organometallic Stereochemistry”, G. Geoffroy, ed., John Wiley & Sons, New York, 1981, pp. 1-36. 4. T. Damhus and C. E. Schaeffer, “Three Reference Systems for Chirality Specification, Application, Geometric Properties, and Mutual Relationships”, Inorg. Chem. 1983, 22, 2406-2412. 5. M. Brorson, T. Damhus, and C. E. Schaeffer, “Exhaustive Examination of Chiral Configurations of Edges on a Regular Octahedron: Analysis of the Possibilities of Assigning Chirality Descriptors within a Generalized ∆/Λ System”, Inorg. Chem. 1983, 22, 1569-1573. 6. T. E. Sloan, “Nomenclature of Coordination Compounds” in Comprehensive Coordination Chemistry, G. Wilkinson, R. D. Gillard, and J. A. McCleverty, eds., Pergamon Press, London, 1987, Part 1, Vol. 1, Chapter 3, pp. 109-134. 137 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 K. CHEMICAL PREFIXES ¶ 309 309. Miscellaneous chemical prefixes. The following list of prefixes most often encountered in the chemical literature (though not necessarily employed in CA index names) is intended to supplement Section H (Illustrative List of Substituent Prefixes); items in Section H are therefore not repeated here. Also excluded are prefixes derived from individual element or compound names, e.g., phospho-, ferri-, aceto-, oxa-, thiazolo-. Prefixes usually italicized are so shown. The lower-case Greek alphabet is supplied in a separate list below (¶ 310). Greek and Latin multiplicative prefixes are also listed separately (¶ 311). ac- abbreviation of alicyclic; as, ac-amino derivatives of Tetralin. Cf. ar-. ace- from acetylene; as, acenaphthene. aci- the acid form: as aci-acetoacetic ester, CH 3 C(OH):CHCOOC 2 H 5 ; acinitro group HON(O):. aldo-, ald- from aldehyde; as, aldohexose, aldoxime. allo- (Greek allos, other) indicating close relation; as, allo-telluric acid, alloocimene (a structural isomer of ocimene). Specifically, designating the more stable of two geometrical isomers; as, allomaleic acid (fumaric acid). amphi- (Greek, both, around) relating to both sides or both kinds; as, amphinaphthoquinone (2,6-naphthalenedione), amphiphile. andro-, andr- (Greek) relating to man, male; as androgen, androsterone. ang- having an angular alignment of rings; as, ang-2′,3′-naphth-1,2-anthracene (pentaphene). Cf. lin-. anhydro- (Greek anhydros, without water) denoting abstraction of water, anhydride of; as, anhydroglucose. Cf. dehydro-. antho-, anth- (Greek) of flowers; as, anthocyanin, anthoxanthin. anthra-, anthr- (Greek, anthrax, coal) of coal or anthracene; as, anthracite, anthraquinone, anthrapyrrole. anti- (Greek, against) opposite, opposed to; as, antioxidant; specifically, equivalent to trans- (which see) as, anti-benzaldoxime. apo- (Greek, from) denoting formation from, or relationship to, another compound; as, apomorphine, C17H17NO2 (morphine is C17H19NO3). ar- abbreviation of aromatic; as, ar-derivatives of Tetralin. as- abbreviation of asymmetric; as, as-trichlorobenzene (1,2,4-Cl3C6H3). benzo-, benz- of benzene; as, benzoic; specifically, denoting fusion of a benzene ring; as, benzoquinoline. bi- (Latin) twice, two, double; specifically: (a) in double proportion; as, bicarbonate (no longer considered good usage); (b) denoting the doubling of an organic radical or molecule; as, biphenyl, C6H5C6H5; bipyridine, C5H4N.C5H4N. bicyclo- of two rings; specifically, designating certain bicyclic bridged compounds, as; bicyclo[2.2.1]heptane. bili- (Latin) of bilirubin, as, biliverdin. bisnor-, dinor- indicating removal of two CH2 groups; as, bisnorcholanic acid or dinorcholanic acid C22H36O2 (cholanic acid is C24H40O2). bufo-, buf- (Latin bufo, toad) derived from the toad; as, bufotalin. chole-, cholo, chol- (Greek) of bile; as, cholesterol, choline. chromo- (Greek chroma, color) color, colored; as, chromophore, chromoprotein, chromoisomer (a colored isomer of a colorless compound). chryso-, chrys- (Greek) gold, golden yellow, yellow; as chrysophanic acid, chrysazin. cincho-, cinch- of cinchoma or cinchonine; as cinchomeronic acid, cinchonan. cis- (Latin, on this side) an isomer in which certain atoms or groups are on the same side of a plane; as, cis-1,4-cyclohexanediol. copro- (Greek) of dung or excrement; as, coprosterol. cyclo- (Greek kyklos, circle) of ring structure, cyclic; as, cyclohexane. D- denoting configurational relationship to D-glyceraldehyde; as, D-fructose. d- (a) abbreviation of dextro or dextrotatory; as, d-strychnine; (b) less properly = D. de-, des- (Latin) indicating removal of something from the molecule; as, deoxybenzoin, C6H5CH2COC6H5 (benzoin with one oxygen atom removed). dehydro- denoting (a) removal of hydrogen; as, dehydrocholic acid; (b) sometimes, removal of water; as, dehydromucic acid. dextro- (Latin dexter, right) rotating the plane of polarization to the right; as, dextropinene. Abbreviation, d; as, d-valine. dl-; d,l- denoting a racemic form. Cf. dextro-, levo-. dvi- (Sanskrit, two, twice) designating provisionally an element of the same family, in the second place beyond; as dvi-manganese (rhenium). eka- (Sanskrit, one) designating provisionally an element of the same family, in the first place beyond; as, eka-manganese (technetium). endo- (Greek, within) indicating an inner position, specifically: (a) in the ring and not in a side chain; (b) attached as a bridge within a ring; as, 1,4-endomethylenecyclohexane (bicyclo[2.2.1]heptane). epi- (Greek, upon, on, to) denoting (a) the 1,6-positions in naphthalene; as, epidichloronaphthalene; (b) in aldoses and related compounds identity of structure except arrangement about the α-carbon atom; as, epirhamnose (epimer of rhamnose); (c) a bridge connection; as, 9,10-epidioxyanthracene (anthracene 9,10-peroxide). ergo-, ergot- relating to ergot; as, ergosterol, ergotamine. erythro-, erythr- (Greek) red; as erythromycin, erythrosine. eso- (Greek, within) denoting immediate attachment to a ring atom. Cf. exo-. etio-, aetio- (Greek aitia, cause) denoting a degradation product; as, etiocholanic acid, etiocobalamin. exo- (Greek) outside, out of; as, exotoxin (an excreted toxin); specifically, denoting attachment in a side chain. Cf. endo, eso-. flavo-, flav- (Latin flavus, yellow) yellow; as, flavoprotein, flavone; specifically, designating certain series of coordination compounds. fuco-, fuc- of fucus (a seaweed); as, fucoxanthin, fucose. gala-, galacto-, galact- (Greek, milk, milky) relating to: (a) milk; as, galactase, galactose; (b) galactose; as, galactocerebroside, galactolipin. gallo-, gall- relating to gallnuts or gallic acid; as, gallotannic acid, gallocatechin. gem- abbreviation of geminate (said of two groups attached to the same atom); as, a gem-diol (e.g., 1,1-ethanediol), the gem-dimethyl grouping in camphor. gluco-, gluc- (a) of glucose; as, glucopyranose, glucuronic acid; (b) less properly = glyco-, glyc-. glyco-, glyc- (Greek) sweet, or relating to sugars or glycine; as, glycogen, glycoside, glycocholic acid. hemato-, hemat-, hemo-, hem- (also haemato-, etc.) (Greek) of blood or its color; as, hematoporphyrin, hematein, hemoglobin, hemin. hetero-, heter- (Greek heteros, other) other, different; as, heteropoly acids, heterocyclic. holo- (Greek) whole, complete; as, holocellulose; holophosphoric acid, H5PO5. homo- (Greek) same, similar; as, homocyclic, homologous (differing by an increase of CH2; as, homophthalic acid). hydro-, hydr- (Greek) (a) denoting presence or addition of hydrogen; as, hydrochloric, hydracrylic; (b) sometimes, relating to water; as hydrate. hyo- (Greek) of swine; as, hyodeoxycholic acid (from hog bile), hyoscyamine (from Hyoscyamus (hog bean)). hypo- (Greek, under, beneath) indicating a lower (or the lowest) state of oxidation; as, hypochlorous acid, hypoxanthine. i- abbreviation of (a) inactive; as, i-tartaric acid; (b) iso-; as, i-pentane. iso- (Greek) equal, alike; as, isomer; usually, denoting an isomer of a compound; as, isocyanic acid; specifically, denoting an isomer having a single, simple branching at the end of a straight chain; as, isopentane, (CH3)2CHCH2CH3. keto-, ket- from ketone; as, ketohexose, ketoxime. L- configurationally related to L-glyceraldehyde; as, L-fructose. l- (a) abbreviation of levo or levorotatory; as, l-strychnine; (b) less properly = L-. lano- (Latin) of wool; as, lanosterol (from wool fat). leuco-, leuc- (Greek) colorless, white; as, leucine; specifically, a colorless reduced derivative of a triphenylmethane dye; as, leucomethylene blue. levo-, laevo- (Latin laevus, left) rotating the plane of polarization to the left; as, levovaline. Abbreviation, l-; as, l-valine. lin- denoting a straight, linear alignment of rings; as lin-naphthanthracene (pentacene). Cf. ang-. litho-, lith- (Greek lithos, stone) related to stone or calculus; as, litharge, lithocholic acid (from gallstones). luteo- (Latin luteus) orange-yellow, brownish yellow; as luteolin; specifically, the coordination compounds [M(NH3)6]Cl3. m- abbreviation of meta (sense c). meso-, mes- (Greek) middle, intermediate; specifically; (a) an intermediate hydrated form of an inorganic acid; as, mesoperiodic acid, H3IO6; (b) optically inactive owing to internal compensation; as, mesotartaric acid; (c) (abbreviated µ-) centrally substituted; as, meso-chloroanthracene (9-chloroanthracene), meso-phenylimidazole (2-phenylimidazole); (d) (abbreviated ms-) centrally fused; as, mesonaphthodianthrene (phenanthro[1,10,9,8opqra]perylene). meta-, met- (Greek) indicating changed relation; specifically, designating (a) a low hydrated form of an acid (usually that derived from the “ortho” form by loss of one molecule of water); as, metaphosphoric acid, HPO3; (b) a closely related compound (sometimes, a polymer); as, metaldehyde (trimer of ordinary (acet)aldehyde); (c) (abbreviated m-) the 1,3-positions in benzene; as, m-xylene. n- abbreviation of normal (unbranched); as, n-butane, n-butyl. naphtho-, naphth- (Greek naphtha) relating to naphthalene; as, naphthoquinone. neo- (Greek) new; designating new or recent; as, neoarsphenamine; (of a hydrocarbon) having one carbon atom connected directly to four others; as, neopentane, (CH3)4C. nor- from normal; (a) a lower homologue; as, norcamphane (of which camphane is a trimethyl derivative); (b) a normal (straight-chain) isomer; as, norleucine. o- abbreviation of ortho (sense d). oligo-, olig- (Greek oligos, small) meaning few; as, oligosaccharide. ortho- (Greek, straight, right, true) (a) the fully hydrated form of an acid; as, orthonitric acid, H5NO5; (b) the highest-hydrated stable form; as, orthophosphoric acid, H3PO4; (c) the common or symmetrical molecular form of an element; as, orthohydrogen; (d) (abbreviated o-) the 1,2-positions in benzene; as, o-xylene. p- abbreviation of para (sense c). para-, par- (Greek, beside, alongside of, beyond) indicating a relationship; as paraxanthine (1,7-dimethylxanthine). Specifically, (a) a higher hydrated form of an acid; as, paraperiodic acid, H3IO5 (preferably called orthoperiodic); (b) a polymer; as, paraldehyde; (c) (abbreviated p-) the 1,4-positions in benzene; as, p-xylene. per- (Latin) complete, thorough, extreme; (a) the highest (or a high) state of oxidation; as, perchloric acid, manganese peroxide (better, dioxide); (b) pres- ¶ 309 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 αβγδεζ ηθικλµalpha beta gamma delta epsilon zeta eta theta iota kappa lambda mu νξ ο πρστυϕ χψωnu xi omicron pi rho sigma tau upsilon phi chi psi omega 138 ence of the peroxide group (O2); as, barium peroxide, perbenzoic acid, per acid (better, peroxy acid); (c) exhaustive substitution or addition; as, perchloroethylene, C2Cl4; perhydronaphthalene, C10H18. peri- (Greek, around, about) (a) the 1,8-positions in naphthalene; as peri-dinitronaphthalene (b) in polycyclic ring systems, fusion of a ring to two or more adjoining rings: as, perinaphthindene (phenalene). peroxy- containing the peroxide group (O2); as, peroxymonosulfuric acid, HOSO2OOH. pheno-, phen- (from phene, benzene) related to phenyl or benzene; as, phenacyl; specifically, an anthracene analogue having two hetero atoms in the central positions; as, phenazine, phenothiazine. phloro-, phlor- relating to phlorizin; as, phloroglucinol, phloretin. phthalo-, phthal- relating to phthalic acid; as, phthalocyanine, phthalide. phyllo-, phyll- (Greek phyllos) of leaves; as, phylloporphyrin. phyto-, phyt- (Greek) relating to plants; as, phytosterol, phytohormones. picro-, picr- (Greek) bitter; as, picrotoxin, picric acid. pino-, pin- (Latin pinus, pine) relating to pine or pinene; as, pinic acid, pinocarvone. poly- (Greek) many; as, polymer, polysulfide, polysaccharide. pro- (Greek, before) a precursor; as proenzyme, provitamin. proto-, prot- (Greek) first; specifically, designating: (a) first in an inorganic series; as, protoxide (lowest in oxygen content); (b) parent or immediate antecedent; as, protactinium, protochlorophyll. pseudo-, pseud- abbreviated ψ or ps (Greek, false) indicating resemblance to, or relation (especially isomerism) with; as, ψ-cumene, pseudaconitine, pseudobase. Abbreviation: as, ψ-cumene. purpuro- (Latin purpura, purple) indicating purple or red color; as, purpurogallin. pyo- py- (Greek) relating to pus; as, pyocyanine. pyro-, pyr- (Greek pyr, fire) indicating formation by heat; as, pyrocinchonic acid, pyrene; specifically, designating an acid derived from two molecules of an “ortho” acid by loss of 1H2O; as, pyrophosphoric acid, H4P2O7 (2H3PO4-H2O). pyrrolo-, pyrro-, pyrr- containing the pyrrole ring; as, pyrrolopyridine, pyrrocoline. reso-, res- relating to resorcinol; as, resorufin, resazurin. rhodo-, rhod- (Greek rhodon, rose) rose-red; as, rhodoporphyrin, rhodamine. s- abbreviation of (a) symmetric(al); (b) secondary. sapo- (Latin, soap) relating to soap or soap bark; as saponin, sapogenin. sec- abbreviation of secondary; as, sec-butyl. seco- (Latin secare, to cut) denoting ring cleavage; as, 16,17-secoandrostane. sub- (Latin, under, below) denoting (a) a low proportion (or deficiency, as in a basic salt); as, subiodide, suboxide, aluminum subacetate. super- (Latin, above, over) denoting a high proportion (or superfluity, as in an acid salt); as, superoxide (peroxide), superphosphate. sym- abbreviation of symmetric(al); as sym-dichloroethylene (1,2-dichloroethene). syn- (Greek, with, together) equivalent to cis (which see); as, syn-benzaldoxime. t- abbreviation of tertiary; as, t-butyl. tauro- (Latin taurus, bull) relating to bulls or to taurine; as, taurocholic acid, taurocyamine. tere- (Latin terebinthus, terebinth) relating to terebene or terpenes; as, terephthalic, teresantalic. tert- abbreviation of tertiary; as, tert-butyl. thymo-, thym- relating to (a) thyme; as, thymoquinone, thymol; (b) the thymus; as, thymonucleic. trans- (Latin, across) an isomer in which certain atoms or groups are on opposite sides of a plane; as, trans-cinnamic acid. uns-, unsym- abbreviations of unsymmetrical; as, uns-dichloroethane, CH3CHCl2. uro-, ur- (Greek ouro-, our-) relating to urine or urea; as, urobilin, urethane, uric acid. urso-, urs- (Latin ursus, bear) relating to bears or the bearberry; as, ursolic acid. v- abbreviation of vicinal; as, v-triazine. verdo- (French, verd, vert, green) indicating green color; as, verdohemin. vic- abbreviation of vicinal; as, vic-triazole. xantho-, xanth- (Greek) yellow; as, xanthotoxin, xanthic acids, xanthine. xylo-, xyl- (Greek xylon, wood) relating to wood, xylene, or xylose; as, xylan, xylidine, xyloquinone, xylocaine. zymo-, zym- (Greek zyme, leaven) relating to a ferment or fermentation; as, zymosterol, zymase. 310. Greek alphabet. Lower-case Greek letters are employed in the chemical literature to number carbon chains and to indicate the size of lactone rings (a γ-lactone generally contains a furan ring, a δ-lactone a pyran ring, and so on). In CA names, Greek letters are reserved for the acyclic portion of conjunctive index parents (see ¶ 124), while cyclic portions are numbered with arabic numbers. Of Greek capital letters, ∆ (delta) is sometimes encountered in the literature to denote a double bond); Τ (tau) indicates a triple bond. Some lowercase letters have additional meanings; ϕ (phi) is a shorthand version of “phenyl” or “Ph”; see also “meso” and “pseudo” in ¶ 309. 311. Multiplicative prefixes. In CA index names, Greek prefixes are preferred, except for nona- (for nine), and undeca- (for eleven). The terms hemi(Greek) and sesqui- (Latin) were employed by CA in hydrate and ammoniate names prior to the Twelfth Collective period (1987-1991) (see ¶¶ 192, 265A). For use of the special terms bis-, tris-, tetrakis-, etc., with complex terms and to avoid ambiguity, see ¶¶ 110 and 266. Greek 1 11/2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 40 50 60 70 80 90 100 101 102 110 120 132 200 300 400 1000 1/ 2 Latin semiunisesquibitri-, terquadri-, quadr-, quaterquinque-, quinqusexi-, sexsepti-, sept- hemimono-, monditritetra-, tetr- penta-, penthexa-, hexhepta-, heptocta-, oct-, octo-, octinona-, non-, noviennea-, ennedeca-, dec-, deciundeca-, undechendeca-, hendecdodeca-, dodectrideca-, tridectetradeca-, tetradecpentadeca-, pentadechexadeca- hexadecheptadeca-, heptadecoctadeca-, octadecnonadeca-, nonadeceicosa-, eicosheneicosa-, heneicosdocosa-, docostricosa-, tricostetracosa-, tetracospentacosa-, pentacoshexacosa-, hexacosheptacosa-, heptacosoctacosa-, octacosnonacosa-, nonacostriaconta- triaconthentriaconta-, hentriacontdotriaconta-, dotriaconttritriaconta-, tritriaconttetraconta-, tetracontpentaconta-, pentaconthexaconta-, hexacontheptaconta-, heptacontoctaconta-, octacontnonaconta-, nonaconthecta-, hecthenhecta-, henhectdohecta-, dohectdecahecta-, decahecteicosahecta-, eicosahectdotriacontahecta-, dotriacontahectadicta-, dicttricta1 tetracta1 kilia1 1 International Union of Pure and Applied Chemistry, Organic Chemistry Division, Commission on Nomenclature of Organic Chemistry, “Extension of Rules A-1.1 and A-2.5 Concerning Numerical Terms Used in Organic Chemical Nomenclature (Recommendations 1986)”, Pure Appl. Chem. 1986, 58, 1693-6. 139 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 L. CHEMICAL STRUCTURAL DIAGRAMS FROM CA INDEX NAMES ¶ 315 Introduction Form of CA index names Deriving a chemical structural diagram Index heading parents ¶ 312 313 314 315 Substituent prefixes Modifications Stereochemistry ¶ 316 317 318 312. Introduction. The foregoing sections of this document are concerned with selection of index names for chemical substances, but the user of CA printed indexes and computer-readable files often needs to proceed from a CA index name to the structure diagram of a chemical substance. The aim of this section is therefore to describe succinctly the form of CA index names, to illustrate the procedure for deriving a chemical structural diagram from a CA index name, and to show where in CAS publications structural data can be found. The structural diagrams accurately represent the positions of atoms relative to each other in a molecule but because of molecular flexibility, crowding, and/or the need to draw a three-dimensional structure in two dimensions, some structural diagrams are, of necessity, distorted. For example, some bond lengths and angles may differ from those in the molecule represented.1 313. Form of CA index names. The complexity of chemical substances generally dictates the complexity of CA index names. The CA index name consists of up to five fragments, namely, the index heading parent alone or followed successively by the substituent, modification, and stereochemistry fragments (compare ¶104), as necessary. Some index heading parents are followed by synonym line formulas (compare ¶¶219, 315.II). Every name contains an index heading parent and it is by citing the parent first (i.e., in an inverted format) that the names of related chemical substances are listed together in the printed indexes. 314. Deriving a chemical structural diagram from a CA index name proceeds by taking each name fragment sequentially, converting it into a structural fragment, and then placing each structural fragment in its proper position in the diagram, using the appropriate positional information. The complete derivation of a chemical structural diagram may require up to four steps, depending upon the complexity of the chemical substance, each based on one of the four possible CA index name fragments. This process is illustrated in the remaining paragraphs of this section. 315. Index heading parents include the largest or most important molecular skeleton and (when present) the highest function in a chemical substance (see ¶¶ 130, 164). I. Index heading parents that stand alone. The simplest index heading parents may be illustrated by examples such as the following: Butane Chlorine 2-Hexene Nickel The names of acyclic hydrocarbons are discussed in ¶ 141 and the multiplicative terms that indicate the number of carbon atoms in a hydrocarbon are listed in ¶ 311. Element names are discussed in ¶ 219. Some index heading parents are made up of two parts: a basic skeleton name and a principal functional suffix. Principal functional suffixes are discussed in detail in Section C (¶¶ 164-177). Example: Basic skeleton name Principal functional suffix Example: Basic skeleton name Locant Principal functional suffix 2- Pyridine carbothioamide S 1 6 = 2 N C−NH2 The Chemical Substance Index contains the following entry for pyridine. Pyridine 6 1 N The carbothioamide principal function suffix is discussed in detail with other amide groups in ¶¶ 171 and 233. The locant, 2, indicates where the carbothioamide group is attached to the pyridine ring (¶ 115). Another type of two-part name, known as a “conjunctive name” (see ¶ 124), is a combination of the name of a cyclic molecular skeleton and the name(s) of one or more identical, saturated acyclic hydrocarbon chains, each terminated by the same functional group. Example: Locant Cyclic molecular skeleton Greek multiplicative prefix Acyclic hydrocarbon chain terminated by a functional group [1,1′:3′,1′′ -Terphenyl] -4,4′′ - di methanethiol H SCH 2 4 1 1′ 3′ 1 ′′ 4 ′′ CH 2 SH Methan amine MeNH2 The structure of the phenyl group is found in the Illustrative List of Substituent Prefixes (¶ 294). That “ter” is a Latin prefix meaning “three” is found in ¶ 311. The first set of locants (1,1′:3′,1′′) indicates that the three benzene rings are connected as shown. The second set of locants (4,4′′) shows that the two methanethiol groups (see ¶¶ 141 and 175) are attached as shown to the first and third benzene rings. Such “ring assembly” names are described in ¶ 157. Polymers are named either on the basis of the monomers from which they are formed (see ¶ 317) or on the basis of their structure, as represented by a structural repeating unit (compare ¶ 222). In the latter, the multivalent radicals are cited in sequence, following the term “Poly”, and can be drawn from left to right. Each radical retains its own numbering and is oriented, if possible, so that the point of attachment at the left of the radical is assigned the lowest possible locant. Example: Poly[(4,4-dimethyl-2,5-dioxo-1,3-imidazolidinediyl)-1,4-phenyleneoxy-1,4-phenylene] O The basic skeleton is the one-carbon unit “Methane” (¶ 141), the final “e” being elided before a vowel. The principal (here, the only) functional group is the amine (¶ 176). 1 N O 2 54 3 N Me 1 4 O 1 4 Me n 1A. L. Goodson, “Graphical Representation of Chemical Structures in Chemical Abstracts Service Publications”, J. Chem. Inf. Comput. Sci. 1980, 20, 212-217. In this chemical structural diagram, the multivalent radicals are separated by dashed vertical lines and the numbering of each radical is shown, where appropriate. The structures of the radicals (e.g., oxy, phenylene) are found in ¶ 294 or can be inferred from the chemical structural diagrams associated with parent names (e.g., imidazolidine) in the Ring Systems Handbook or the Chemical Substance Index. The meanings of the methyl and oxo terms can also be determined from ¶ 294. ¶ 315 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Cyclic stereoparent: 140 II. Index heading parents with synonym line formulas. Synonym line formulas are molecular formulas which follow the index heading parent. They are printed in boldface and are enclosed in parentheses. They are often useful for resolving ambiguity, where two or more substances, usually inorganic (see ¶ 219), have the same name. Examples: Aluminum calcium titanium oxide (Al2CaTiO6) Aluminum calcium titanium oxide (Al2Ca4Ti2O11) Lack of a synonym line formula in such a case means that the author did not provide the necessary specificity in the original document. Example: Aluminum calcium titanium oxide Rifamycin ((2S,12Z,14E,16S,17S,18R,19R,20R,21S,22R, 23S,24E)-21-(acetyloxy)-5,6,9,17,19-pentahydroxy-23methoxy-2,4,12,16,18,20,22-heptamethyl-2,7-(epoxypentadeca[1,11,13]trienimino)naphtho[2,1-b]furan-1,11(2H)dione) 32 31 Me HO AcO MeO 25 14 33 Me 20 Me Me 34 O Me OH OH OH 9 1 15 Me 30 NH N III. Index heading parents with chemical structural diagrams. A chemical structural diagram is provided in the Chemical Substance Index where the structure of an inorganic substance (¶ 219) may not be readily apparent from the name. Example: Phosphorodihydrazidothioic acid O H 2 N − NH − P − SH 2 1 35 29 O 12 O 5 11 10 4 OH Me 13 O S or H 2 N − NH − P − OH 2 1 NH − NH 2 1′ 2′ NH − NH 2 1′ 2′ 316. Substituent prefixes (see ¶ 10A) follow the “comma of inversion” (see ¶ 104) in CA index names and their structures can be determined from ¶ 294, the Illustrative List of Substituent Prefixes. Example: 2H-Pyran-2,4(3H)-dione, 3-[[(4-aminophenyl)amino]phenylmethylene]6-phenylThe structure of the chemical substance represented by this name is derived by first obtaining the structure of 2H-Pyran from the Chemical Substance Index or, better, from the Ring Systems Handbook. The Ring Name Index of the 1993 edition of the Ring Systems Handbook reveals that the Ring File (RF) number for 2H-Pyran is RF 2133. Entry RF 2133 in the Ring Systems Handbook is as follows: RF 2133 2H-Pyran C5H6O 289-66-7 1 6 A similar procedure is followed for other types of index heading parents such as cage parents, ring parents, and stereoparents. Here, however, the structural diagrams are published in the Ring Systems Handbook as well as the Chemical Substance Index. Examples: Cage Parent: 1,12-Dicarbadodecaborane(12) H C 6 5 1 HB HB 9 =− =− B H H 4B 2 O H B3 BH 10 B H H B B11 H 8 BH 7 C 12 H Ring Parent: Phenanthrene The index heading parent contains two functional groups which ¶ 174 identifies as ketone groups. However, putting an oxygen on position 4 requires “adding” a hydrogen at position 3. The indicated and added hydrogen terms (see ¶¶ 135 and 136) in the index heading parent thus define the bonding in the ring (the bonding could also be defined by “3,4-dihydro” but that would be part of the substituent fragment of the name and not of the index heading parent, which must be able to stand alone). The complete index heading parent (2HPyran-2,4(3H)-dione) is therefore: 1 9 8 4b 4a 10a 1 O 6 4 2 3 O O As stated in ¶ 313, the complexity of chemical substances generally dictates the complexity of CA index names. This is particularly true for natural products whose names must imply standard orientation and stereochemical representation as well as structure and numbering (compare ¶ 318). Such complexity makes it desirable to use a simple, nonsystematic (“trivial”) name, or stereoparent name, as the index heading parent and to define the stereoparent name by means of a chemical structural diagram. Examples: Acyclic stereoparent: ψ,ψ-Carotene ((6E,8E,10E,12E,14E,16E,18E,20E,22E,24E,26E)2,6,10,14,19,23,27,31-octamethyl-2,6,8,10,12, 14,16,18,20,22,24,26,30-dotriacontatridecaene) 18 ′ 6′ 15 ′ The substituent fragment of the name indicates that a simple substituent (i.e., “phenyl”, see ¶ 294) is attached to the ring at position 6: 1 6 O 2 4 3 O O A complex substituent is attached to the ring at position 3. The second phenyl group is attached through the methylene group (see ¶ 294) to position 3 to yield: 1 17 18 1 6 19 20 Me 15 1′ 17 ′ 6 O 4 2 3 O Me Me Me 11 Me Me 20 ′ 11 ′ CH O Me 18 Me 19 ′ Me Me 16 ′ 141 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 The homopolymer is represented as follows: ( M e 2 CH CM e =CH 2 ) x ¶ 318 The third phenyl group has an amino group (¶ 294) attached to the 4-position and is itself attached through an amino group to the methylene group of the partial structure. The complete structure is therefore: 1 6 O 3 O 318. Stereochemistry for the heading parent is the last structural information described in a CA name. The various symbols used to describe the spatial arrangement of atoms are discussed in ¶ 203. Example: 8-Azabicyclo[3.2.1]octan-3-ol, 8-methyl-, (3-exo)The structure corresponding to the basic skeleton name, principal functional suffix, and substituent is determined as described above. The stereochemistry of the hydroxy group (the methyl group rocks back and forth about the nitrogen atom, eliminating the effects of asymmetry there) is denoted by “(3-exo)-”, the meaning of which is determined from ¶ 203 I. The structure is therefore: 8 C O NH 1 4 NH 2 317. Modifications of the principal functions or other groups follow the substituent(s) (¶ 104). Where derivatives of more than one functional group must be named, the derivative terms are cited in the order described in ¶ 113. Example: 2H-Benzo[g]indazole-2-propanamine, 3,3a,4,5-tetrahydro-N,N-dimethyl-3-phenyl-, hydrochloride (1:3) Only the form 1H-Benzo[g]indazole is illustrated in the Chemical Substance Index and the Ring Systems Handbook: 1H-Benz[g]indazole 1 2 NMe 1 7 5 3 OH HN 9a 9b N 3 4 6 5 The structure is converted into the 2H-isomer and the propanamine group (¶¶ 141 and 176) is attached at the 2-position. (It should be noted that, in conjunctive nomenclature, the function is located at the end of the saturated, acyclic chain furthest from the ring system of the index heading parent (see ¶ 124).) 1 2 N 9a 9b 4 6 5 NCH 2 CH 2 CH 2 NH 2 3 As stated in ¶ 315, stereoparent names (see ¶ 203 II) in the Chemical Substance Index imply (in the absence of cited stereochemical descriptors) a standard structure, including specific stereochemistry, as illustrated by an accompanying structural diagram complete with the numbering system from which locants for substituents and derivatives are derived. With the exception of monosaccharide and some peptide stereoparents, italicized systematic names (and in some cases one or more trivial names) appear as synonyms in parentheses immediately following the (preferred) boldface stereoparent name. In the following examples these systematically named synonyms (1) illustrate the various types of stereochemical descriptors found in CA indexes and (2) show how the use of stereoparents as the preferred CA names for many natural products avoids citation of (often necessarily complicated) stereochemical descriptors. Stereochemical descriptors in the CA index names of coordination compounds reflect the geometry of ligand attachments around one or more central metal atoms (compare ¶ 215). Example: Nickel(1+), bis[[2-(diphenylstibino-κSb)phenyl]diphenylarsine-κ As]iodo-, (T-4)-tetraiodonickelate(2-) (2:1) In this example, the central atom is nickel. The structure of the two large ligands can be determined by reference to ¶ 294. The italicized element symbols (As,Sb) identify the ligating atoms. The stereochemistry symbol (T-4) along with the Kappa indicates that the anion is tetrahedral (see ¶ 203 III). The structure of this coordination compound is therefore: + The four hydrogens are added to the 3, 3a, 4, and 5 positions to saturate the two double bonds; then, when the phenyl and two methyl substituents (see ¶ 294) are attached, the structure becomes: N NCH 2 CH 2 CH 2 NMe 2 The “hydrochloride (1:3)” modification completes the structure: N NCH 2 CH 2 CH 2 NMe 2 • 3HCl Ph2As SbPh2 Ni Ph2As SbPh2 I Ni I 2− I I The modification is also used in naming polymers (¶ 222) on the basis of the monomers from which they are formed. Example: 1-Butene, 2,3-dimethyl-, homopolymer The structure of 1-Butene is deduced from ¶ 141. When the two methyl groups (¶ 294) are attached at positions 2 and 3, the structure becomes: Me Me Me − CH − C= CH 2 4 3 2 1 2 I − − Abeo Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 M. INDEX 142 The references are to paragraphs, not to pages. Trivial and former CA names, general terms and name fragments are listed along with current CA index names. Locants and other numerals, etc., have generally been omitted. Abeo, 212 Acenaphthylene, 148, 152 Acetaldehyde, 173 hydrate, 192 oximes, 195 Acetals, 169, 196 of carbohydrates, 208 retrospective index searching for, 226 of stereoparents, 202 Acetamide, 171 Acetate fibers, 222 Acetates of amines, 198 Acetato, 215 Acetic acid, 165 anhydride-esters, 186 anhydrides, 179 esters, 185 hydrazides, 189 locants for substituents, 117 molecular addition compds., 192 multiplication of, 118 order of precedence of, 106 polymers containing, 222 Acetoacetic acid, 167 Acetone, 174 hydrazone, 190 retrospective index searching for, 262 Acetonitrile, 172 Acetoxy, 175, 283 Acetyl, 134, 168, 174 free radical, 1-oxoethyl as name for, 187 Acetylamino, 134, 171 Acetyl chloride, 170 as substituent, 134 Acetylides, 180 of elements, 219 Acetyloxy, 175, 283 Acid azides, 170 order of precedence of, 106 Acid chlorides. See Acid halides Acid halides, 170 of arsenic and phosphorus acids, 197 of carbohydrates, 208 inorganic, 219 order of precedence of, 106 retrospective index searching for, 227 Acid isocyanates, 183 order of precedence of, 106 Acid radicals, 134, 168, 287 from amino acids, 205 from arsenic acids, 197 from phosphorus acids, 197, 219, 276 hetero-atom-attached, 163, 171, 174 Acids. See also Carboxylic acids; Imidic acids; Sulfonic acids; etc. acyclic, with cyclic substituents, 166 anhydrides—see Anhydrides of arsenic end phosphorus, 197 of carbohydrates, 208 of chlorine, nitrogen, phosphorus, etc., order of precedence of, 106 Class I and Class II, 185 conjunctive names for, 166 epoxy derivs., 166 expressed as suffixes, 164-177 functional derivs., 169 halogen oxo, 188 inorganic “oxo”, 219, 273 isopoly end heteropoly, 219 labeled, 220 ligands from, 215 of metals, 219, 273 order of precedence of, 106, 167 radicals from—see Acid radicals retrospective index searching for, 228, 273 as substituents, 167 Acinitro, 132, 193 Acridine analogs, 149 numbering of, 152 ACS. See American Chemical Society Actinomycins, 206 Acyclic compounds, 141-144 nonfunctional, order of precedence of, 106 Acyl radicals. See Acid radicals Added hydrogen, 136, 256 in cyclic ketones, 174 in ring assemblies, 157 in spiro systems, 156 Additional index entries for anions, 198, 281A for coordination compds., 215 for cyclic peptides, 206 for molecular addition compds., 192, 265A Addition compounds. See Molecular addition compounds Additive nomenclature, 123, 228A Additive terms, 113 locants for, 119 Adducts, 192 Adenine, 122 Adenosine, 210 Adenosine triphosphatase, 218 Adenylic acid, 210 homopolymer, 222 Agar, 208 -al, 173 Alanine, 205 peptides containing, 206 Alanine aminotransferase, 218 Alcohols, 175 carbohydrates as, 208 Class 1, 185 esters, 185 labeled, 220 metal salts, 198 order of precedence of, 106 retrospective index searching for, 229 Aldaric acids, 208 Aldehydes, 173 order of precedence of, 106 oximes, 195 retrospective index searching for, 230 Aldehydic acids, 167, 228 Alditols, 208 Aldonic acids, 208 Aldoses, 208 Alkaline earth metals, 219 Alkaloids, 204 retrospective index searching for, 231 stereochemistry of, 202 steroidal, 211 Alkanes, 141 Alkenes, 141 locants for, 113 Alkenyl radicals locants for, 116 Alkoxy radicals elision in names of, 107 Alkyl radicals, 161 1-imino and 1-oxo derivs., 134, 168 allo, 209 Alloys, 214 labeled, 220 retrospective index searching for, 232 α (alpha), 203, 208, 212 Alphabetization of index names, 121 Alpha particle, 217 Alternating polymers, 222, 277 Aluminate, 215, 219 Aluminum labeled complexes, 220 Aluminum chloride and dimer, 215, 219 Alums, 219 American Chemical Society nomenclature reports of, 302 nomenclature rules of, 296—300 American Mineralogist, 219 Amic acids, 167, 228 Amides, 171 of amino acids, 205 of arsenic and phosphorus acids, 197 of carbohydrate acids, 208, 240 N-hydroxy, 193 order of precedence of, 106 oxides, 268 oximes, 171 peptides, 206 radicals from, 134, 171 retrospective index searching for, 233 tautomerism with imidic acids, 122, 165 unexpressed, 171 Amidines. See Imidamides Amidine tautomerism, 122 Amido, 215 Amidodiphosphoric acid, 219 Amidodiphosphoryl chloride, 219 Amidogen, 187, 219 Amidoimidodisulfuric acid, 219 Amidoimidosulfurous chloride, 219 Amidoselenic acid, 219 Amidoselenonyl fluoride, 219 Amidosulfenyl chloride, 200, 219 Amidosulfoxylic acid, 219 Amidothiodiphosphoric acid, 219 Amidoximes, 171 Amines, 176 boron complexes, 182 N-hydroxy, 193 order of precedence of, 106, 271 retrospective index searching for, 235 salts with acids, 198 Aminium compounds, 184 hydroxides, inner salts, 112 present and former indexing rules for, 270 salts, 198 ylides, 201 Amino, 176 Amino acids, 205 ACS rules for, 302 amides of, 171 homopolymers, 206 polymers, 222 IUPAC-IUB tentative nomenclature rule for, 297 retrospective index searching for, 236 Aminobutyryl in peptide names, 206 Aminocarbonyl, 134 Amino group tautomerism of, 122 Ammines, 215 labeled, 220 Ammonia, 219 Ammoniates, 192 of inorganic salts, 219 Ammonio, 184 Ammonium chloride, 219 Ammonium salts inorganic, 219 organic, 184, 270 Ammoniumyl, 184, 219 Amylopectin, 208 -an in mineral names, 219 Androstane, 211 Androstanol esters, 202 -ane, 146 Aneurine, 224 Angiotensins, 206 Anhydride-esters, 186 Anhydrides, 179 of amino acids, 205 of carbohydrates, 208 of carbonic acid derivs., 183 of cyanic acid, 183 of halogen oxo acids, 188 of inorganic with organic acids, 219 as modification terms, 112, 113 143 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 -ate, 219 Atisane, 212 -ato ligands, 215 Aurate, 215 Aza, 128 Azacycloundecane, 146 Azahomoandrostane, 211 Azete, 146 Azi, 161 Azides acid, 170 acid, order of precedence of, 106 Azidodisulfuric acid, 219 Azidosulfuric acid, 219 Azines, 190 Azino, 161, 193 Aziridine, 146 Azo, 161, 193 Azo compounds, 193, 218 dyes, 216 retrospective index searching for, 238 Azomethines, 176 Azonia, 184 Azoxy compounds, 193 retrospective index searching for, 238 Balata, 222 Barbituric acid, 122 Baryon, 217 Base components carbocyclic, of fused systems, 148 heterocyclic, of fused systems, 149, 281 selection of, 150 Benzaldehyde, 173 Benzenamine, 176 Benzenaminium hydroxide, inner salts, 201 Benzene alkoxy derivs., 196 in fused systems, 149, 151 multiplication of, 118 preferred to cyclohexane, 138 radicals from, 161 ring assemblies of, 157, 163 Benzenecarbothioic acid hydrazide, 189 Benzenecarbothioyl chloride, 170 Benzenecarboximidic acid, 129, 165 Benzenediacetic acid derivs., 124 Benzenediazonium compounds, 198 Benzenedicarboxylic acid polymers, 222 Benzenedipropanoic acid, 166 Benzenemethanol, 124 derivs., 131 Benzenepropanal hydrazones, 190 Benzenesulfonamide, 171 Benzenesulfonic acid anhydrides, 179 Benzenethiol esters, 185 Benzenide, 180 Benzeno, 154 Benzimidazole tautomers, 122 Benzimidazolium compounds, 184 Benzindene, 150 Benzisothlazole abnormal valency in, 158 Benzo, 149 elision of, 107 Benzodioxaborole, 182 Benzofuran, 149 Benzogermole, 194 Benzoic acid, 165 anhydrides, 179 derivs., 131 esters, 185 order of precedence of, 106 Benzonitrile, 172 Benzopyran as fusion component, 152 Benzopyranol vitamin E derivs., 224 Benzopyranone, 185 Benzothiazolium compounds, 184 dyes, 216 Benzothienyl, 161 Bori with partial esters, 186 retrospective index searching for, 237 anhydro, 208 Anhydro, 139 Anhydrosulfides, 179, 197, 200 “bis” and parentheses used with, 110 of inorganic acids, 219 of thiocyanic acid, 183 Anilic acids, 167, 228 Anilides, 171, 233 Anils, 176 Anions, 180 additional index entries, 198, 281A citation in modifications, 113 common, 198, 281A complex, 215 of elements, 219 in modifications, 198 -anium, 184 “a” nomenclature. See Replacement nomenclature Anthracene in fused systems, 148, 151 numbering of, 152 preferred to phenanthrene, 138 Anthracenedione, 136 anti, 203 Antielements, 217 Antihelium, 217 Antimonate, 215 Antimonide, 180 Antimony defined as metal, 101, 181, 215, 219, 257 Antimony compounds, 181 monocyclic, 146 order of precedence of, 106 Von Baeyer systems, 155 Antimony hydroxide, 181, 219 Antiparticles, 217 Antiproton, 217 Apamin, 206 Apiose, 208 Apocarotenes, 212 Aqua, 219 ar, 120 Arabinan, 208 arabinose, 208 Arrow nomenclature, 208, 210 Arsenamldic acid, 197 Arsenenic acid, 197 Arsenenous acid, 197 Arsenic acids, 197, 273 anhydrides, 179 inorganic, and salts, 219 Arsenic compounds, 197 order of precedence of, 106 tautomeric, 122 Arsenic triamide, 197 Arsenides, 180 of elements, 219 Arsenido, 215 Arsenous acid, 197 Arsindole, 149 Arsine, 143, 197 Arsine selenide, 197 Arsine sulfide, 197, 200 Arsinic acid, 197 Arsino, 161, 197 Arsinous acid, 197 Arsinous cyanide, 197 Arsinyl, 197 Arsonic acid, 197 derivs., 271 Arsonimidous acid, 129 Arsonium compounds, 184 Arsonous acid, 197 Arsorane, 140, 143, 197 as, 108 Ascorbic acid, 208, 224 -ase, 218 Asparaginase, 218 Aspartic acid peptides containing, 206 Aspartoyl, 205 Assumptions for amino acid end peptide stereochemistry, 205, 206 for biline stereochemistry, 223 for coordination stereochemistry, 203 for polymer SRU names, 222 Benzoxazine, 149 Benzoxazole, 149 Benzoyl, 134, 168, 174 Benzoyl isocyanide, 170 Benzyl alcohol, 124 derivs., 131 Benzyne, 145 Beryllium chloride, 219 β (beta), 203, 208, 212 Beta particle, 217 Bibicyclo, 157 Bibliography of nomenclature of chemical substances, 295-308 Bicyclodecasilane, 155 Blcycloheptyl “bis” and parentheses used with, 110 Bicyclohexadienyldiylidene, 161 Bicyclohexenyl, 157 Bicyclohexyl, 157 Bicyclo systems. See Von Baeyer systems Bicyclotetrasilazane, 155 Bicyclotetrasiloxanyl, 157 Bicycloundecane, 155 Biguanidine, 251 Biisoquinoline, 157 Bile pigments, 223 retrospective index searching for, 278 Biline, 223, 278 “Bimol.” in anhydride names, 179 Bi names. See Ring assemblies Binaphthalene, 157, 266, 281 Binaphthalenediyl, 161 Binary compounds, 219 Biochemistry nomenclature of, history and development of, 305 nomenclature rules for, 297 Bipentaborane, 159 Biphenyl, 114, 157, 281 locants in, 113 Biphenyldlyl, 125, 161 Biphenylyl, 161 punctuation for, 109, 110 Biphenylylcarbonyl, 168 Bipiperidine, 157 Bipyridinedlyl, 161 Bis, 110, 266 alphabetization rules for names containing, 121 enclosing marks following, 109 in multiplicative names, 125 in ordering of substituents, 121 Bismuth compounds, 181 monocyclic, 146 order of precedence of, 106 Bismuth hydroxide, 181 Bismuthine, 143, 181 Bismuthine imide, 181 Bismuthine oxide, 181 Bismuthino, 161, 181 Bisulfite addition compounds, 192 Bithiazole polymers, 222 Bithiazolyl, 161 Bitriazole, 157 Block polymers, 222,277 Bohrium, 219 Bonds metal-metal, 203 multiple—see Unsaturated compounds Bora, 128 Boranamine, 182 Borane, 159, 182 free radicals from, 187 order of precedence of, 106 oxybis-, derivs., 179 trifluoro-, 257 Boranetriamine, 182 Boranthrene, 149 Borate (1-), 106, 182 Borates aminium, 201 complex, 215 Borazine, 146, 182 Boric acid, 182, 219 anhydride-esters, 186 anhydrides, 179 Borinic acid, 182 Boro Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 acyclic and cyclic, order of precedence of, 106 ions, 180, 184, 219 Carbon dioxide, 219 Carbon disulfide, 219 Carbonic acid, 183 cyclic esters, 196 anhydrides, 179 anhydride with silicic acid, 199 derivs., retrospective index searching for, 241 order of precedence of, 106, 271 and related compounds, 183 replacement names from, 129 Carbonic bromide chloride, 183 Carbonic dihydrazide, 183, 189 Carbonimidic acid, 183 Carbonimidoyl, 134, 168, 174 in multiplicative names, 125 Carbonitriles, 172 Carbonium compounds, 184 Carbon monoxide, 219 Carbonochloridic acid, 183 Carbonochloridothioic acid anhydrosulfides, 170 Carbonodiperoxoic acid, 129, 183 Carbonodithioic acid anhydrosulfides, 200 Carbonohydrazonic acid, 129 Carbonohydrazonoyl, 134 Carbonothioic dichloride, 183 Carbonothioyl, 134, 168, 174 in multiplicative names, 125 Carbon oxide sulfide, 219 Carbon tetrachloride, 272 Carbonyl, 134, 168, 174 free radicals containing, 187 hetero-atom-attached, 163 in multiplicative names, 125 Carbonyldiimino, 134 Carbonyls metal, 215, 219 Carbostyril, 122 Carbothioamides elision in names of, 107 Carbothioic acids, 165 Carboxaldehydes, 173, 230 Carboxamides, 171, 233 tautomerism of, 122 Carboximides, 191 Carboximidic acids, 129, 165 tautomerism of, 122 carboxy, 220 Carboxy, 134 Carboxyamino, 183 Carboxylato, 215 Carboxylic acids, 165 acyclic with cyclic substituents, 166 aminium salts, 198 anhydrides with inorganic acids, 219 of carbohydrates, 208 esters, 185 free radicals from, 187 functional derivs., 169 labeled, 220 molecular addition compds., 192 order of precedence of, 106, 167 retrospective index searching for, 228 salts, 198 as substituents, 167 Cardanolide, 211 Carotene, 212 Carotenoids, 212 ACS report on nomenclature of, 302 IUPAC tentative nomenclature rules for, 296 Carrageenan mixtures containing, 221 Cast iron, 214 Categories for elements, 219 Catena compounds, 192 Cations, 184 complex, 215 elementary and inorganic, 219 order of precedence of, 106 present and former indexing rules for, 270 salts, 198 Cellulose, 208, 240 Centrality 144 Borole, 182 Boron acids, 182 anhydrides, 179, 182 esters, 185 hydrazides, 182 Boron complexes, 201 Boron compounds, 159, 182 inorganic, IUPAC report on, 298 molecular skeletons, 159 order of precedence of, 106 retrospective index searching for, 239 zwitterionic, 201 Boronic acid, 182 Boron metaphosphate, 219 Boron phosphate, 219 Boroxin, 146 Borthiin, 146 Boryl, 161 Boson, 217 Boughton system for isotopes, 220 Brackets, 109 around complex radicals, 132 around locants in spiro names, 156 in multiplicative names, 125 Bradykinin, 206 Brass, 214 Bridged fused systems, 154 Bridged systems, 140, 147, 155 choice between, 138 fused, 154 indicated hydrogen in, 135 Von Baeyer names for, 155 Bromic acid, 188 Bromo, 131 Bromous acid, 219 Bronze, 214 Bufanolide, 211 Butanedioic acid anhydride-esters, 186 Butanediol fibers from dioic acids and, 222 Butenone, 137 Butyne metal derivs., 219 Butyryl in peptide names, 206 220 CA. See Chemical Abstracts Cadinane, 212 Caerulein, 206 Caffeine, 122 Cahn-Ingold-Prelog rule. See Sequence rule Calciferol, 224 Calcitonin, 206 Calcium carbide, 219 Camphor, 212 Carbaboranes, 160, 182 Carbamic acid, 183 conjunctive names not formed from, 124 as elided name, 107 esters, 185 hydroxy, 193 multiplication of, 118 Carbamic chloride, 183 Carbamimidic acid, 183 Carbamoyl, 134 Carbapolyboranes order of precedence of, 106 Carbazole numbering of, 152 Carbide, 219 Carbocyclic compounds, 145, 147, 148 monocyclic, radicals from, 161 order of precedence of, 106 spiro, 156 Carbodiimide, 177, 191 Carbodithioic acids, 165, 200 Carbohydrates, 208 ACS nomenclature rules for, 302 IUPAC tentetive nomenclature rules for, 296 retrospective index searching for, 240 Carbohydrazide, 252 Carbohydrazones, 190 Carbohydrazonic acids, 165 Carbon compounds. See also Carbocyclic compounds acyclic, 141 14C, in amines, 176 in index name selection, 138, 255 Cephalosporins stereochemistry of, 203 Cermets, 214 Cevane, 211 Chemical Abstracts index nomenclature for, reports on, 301 Chicle, 222 Chirality. See Stereochemistry chiro, 209 Chloramido, 215 Chloramine, 219 Chloric acid, 219 metal salts, 219 Chlorides of arsenic and phosphorus acids, 197 of elements, 219 glycosyl, 208 Chlorine compounds, 188 Chlorine nitrate, 219 Chlorine oxide, 219 Chloro, 132 Chlorocarbonyl, 131 Chloroimidosulfuric acid, 219 Chloronium, 219 Chlorophylls, 233 Chlorosulfuric acid, 129, 219 Chlorosyl, 219 Chloryl, 188, 219 Chloryl fluoride, 219 Chloryloxy, 188 Cholane, 211 Cholecalciferol, 224 Cholestane, 211 Chromates complex, 215 Chromatite, 219 Chrome alums, 219 Chromic acid, 219, 273 Chromium carbonyl, 219 Chromium hydroxide, 219 Chromyl, 219 Chymotrypsin, 218 cis, 203, 209 C.I. names, 216 Cinchonanol salts, 202 Cinnoline, 149 35Cl, 220 Class I acids, 185, 247 Class I alcohols and thiols, 185, 247 Cluster compounds, 203, 215, 219 Cobalamin, 224 Cobalt labeled complexes, 220 Cobaltate, 219 Cobalt nitrate sulfate, 219 Cobamic acid, 224 Cobamide, 224 Cobinamide, 224 Cobinic acid, 224 Cobyrinic acid, 224 Cocarboxylase, 224 Coenzyme A, 210 Colons, 108 in coordination names, 215 in index names, 108 Colour Index, 216 Commas, 108 of inversion, 104 in modifications, 108 Common components of addition compds., 192, 265A of salts, 198, 281A Complexes. See Coordination compounds Complexity principle of, discontinuance of, 255 Compound classes order of precedence of, 106 Compound radicals, 133, 162 Conanine, 211 Configuration. See Stereochemistry Configuration numbers for coordination compds., 203 Conjugate acids, 184 labeled, 220 Conjunctive nomenclature, 124, 315 for acids, 166 145 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 in phorbine names, 223 Dehydrogenase, 218 Deoxo, 204 Deoxy, 139, 204, 208 Depsipeptides, 206 Derivatives. See Functional derivatives Desulfo, 206 Deuterium, 220 Di, 110 Diarsene, 143 Diarsine, 197 Diarsonous acid, 179 Diazadiphosphetidine, 197 Diazane. See Hydrazine Diazaporphine, 223 Diazene and derivs., 193 order of precedence of, 106 Diazenecarboxaldehyde hydrazones, 190 Diazenecarboxylic acid hydrazides, 189 Diazenyl, 161 Diazenyloxy free radical, 187 Diazo, 132 “bis” and parentheses used with, 110 Diazoamino tautomerism, 122 Diazo compounds, 193 retrospective index searching for, 243 Diazonio, 184 Diazonium compounds, 184 double salts, 216 salts, 198 Dibismuthine, 143 Diborane, 159, 182 Dicarbadodecaborane, 160, 182 Dicarbaheptaborane, 160 Dicarbonic acid, 179 Dicarbonic dichloride, 183 Dicarboxylic acids esters and hydrazides, 119 Didehydro, 139, 146, 208 in phorbine names, 223 Diels-Alder adducts, 192 Diene adducts, 192 Diethylamino alphabetization of, 121 Digermaselenane, 144 Diimidotricarbonimidic acid, 183 Diimidotriphosphoramide, 197 Dilmidotrisulfuric acid, 219 Dimers of aluminum chloride, 215, 219 of boranamines, 182 Dinorcholestanoic acid, 211 Dioic acids, 165 Diols esters, 119, 185 Diones, 174 cyclic, 136 derivs., 119 Dioxaazadispirododecene, 156 Dioxacyclopentindene, 153 Dioxagermanin, 199 Dioxastannin, 146 Dioxy, 196 in free radical names, 187 Diphosphine, 197 order of precedence of, 106 sulfides, 200 Diphosphinediyl, 161 Diphosphinium, 219 Diphosphinyl, 161, 197 Diphosphonic acid, 179 Diphosphorane, 143 Diphosphoric acid, 197, 219 esters, 119 nucleotide esters, 210 Diphosphoric(III,V) acid, 219 Diphosphorous acid, 219 Diphosphorous tetramide, 219 Diphosphoryl, 219 Diphosphoryl, chloride, 197 Diphosphoryl chloride fluoride, 219 Diplumboxane, 199 Diselenides, 200 Diselenious acid, 219 Disilane, 199 order of precedence of, 106 epin present and former policies of, 255 Constitutional repeating units, 222 Coordination compounds, 215 amino acid transition metal salts as, 205 labeled, 220 order of precedence of, 106 polymers of, 222 porphyrin complexes, 223 retrospective index searching for, 242 stereochemistry of, 203 structural diagram derivation for, 318 sulfur complexes as, 200 Copolymers, 222 Copper monocysteine complex, 205 Corrin, 224 Corrinoids. See also Vitamin B12 IUPAC-IUB tentative nomenclature rules for, 297 Corticotropins, 206 Coumarins, 185 Cuprates complex, 215 Cyanamide, 183, 267 Cyanates of arsenic and phosphorus acids, 197 Cyanato, 183, 188, 215 Cyanic acid, 183, 188, 219 anhydrides, 170, 179 esters, 185, 188 Cyanides of arsenic and phosphorus acids, 197 Cyanine dyes, 216 Cyano, 172 Cyanocobalamin, 224 Cyanosulfurous acid, 219 Cyclic(glycylglycylglycyl), 206 Cyclitols, 209 IUPAC tentative nomenclature rules for, 296 Cycloalkanes, 145 Cycloalkenes, 145 Cycloalkenyl radicals locants for, 116 Cycloandrostane, 211 Cyclodisilazane, 146 Cyclohexadienyne, 145 Cyclohexanamine salts, 198 Cyclohexane, 130 benzene preferred to, 138 polyhydroxy derivs., 209 terpene derivs., 212 Cyclohexasiloxane, 146 Cyclohexastannane, 199 Cyclohexene, 145 no locant used with, 113 Cyclohexenone, 174 Cyclohexenylylidene, 161 Cyclohexyl, 161 Cyclopentadiene, 145 Cyclopentadienide, 180 Cyclopentadienyl, 161 in metal complexes, 215 Cyclopentane fused derivs., 151 Cyclopentaphenanthrene bridged derivs., 154 derivs., 211 and derivs., numbering of, 152 Cyclopregnane, 211 Cyclopropenyl, 161 Cyclosecopregnane, 211 Cyclosiloxanes, 146 Cyclotrisiloxanol, 199 Cysteine, 205 Cytidine, 210 Cytidylic acid, 210 Cytochalasan, 202 Cytochrome c, 207 Cytosine, 122 d D, Disilanehexol, 219 Disilathiane, 199 order of precedence of, 106 Disilazane, 144, 199 radicals from, 144 Disilazanedlyl, 161 Disilanyl, 199 Disilazanyl, 144, 199 Disilene, 143 Disiloxane, 199 order of precedence of, 106 Disiloxanediol, 131 Disiloxanediyl, 125 as hetero unit, 127 Disiloxanyl, 161 Distannane, 140 Distannazane radicals from, 144 Distibene, 181 Distibenediyl, 161 Distibine, 181 Disulfamide, 219 (Disulfate), 109 Disulfides, 200 acyl, 179 chloro, 170 order of precedence of, 106 phosphono sulfo, 219 Disulfones order of precedence of, 106 Disulfonothioic acids, 165 Disulfonyl, 219 Disulfoxides, 200 order of precedence of, 106 Disulfuric acid and salts, 109, 219 Dithiastibabicyclononatriene, 155 Dithiazine, 146 Dithiin, 135 Dlthio as hetero unit, 127 Dithiocarboxy, 134 Dithioperoxoic acids, 165, 200 Diylidene, 161 Diyl, 161 DL, 108, 205, 208 Double bonds. See Unsaturated compounds Double salts, 219 Dyes, 216 retrospective index searching for, 244 E, 203 report on, 301 Earliest index position principle of, 122 of radical names, 133 of total index names, 138 E.C., 218 -ecane, 146 -ecin, 146 -ecine, 146 Egg White mixtures containing, 221 Element, 104, 219 Element, 105, 219 Elementary particles, 217 retrospective index searching for, 245 Elements, 219 of atomic number 104 and higher, 101 isotopes of, 220 Elision of vowels and syllables, 107, 283 enantio, 206 Enclosing marks, 109 in complex radicals, 132 in indefinite names, 132 in labeled radicals, 220 in ligand names, 215 in uninverted multiplicative names, 192 endo, 154, 203, 206 -ene, 139, 141, 155 no elision of “a” before, 142 -enyl, 161 Enzymes, 218 retrospective index searching for, 246 -epane, 146 epi, 209 Epidioxy, 154, 211 -epin, 146 -epine, 146 in deuterium-labeled compds., 220 108, 205, 208, 209 De, 206 Decaborane, 159 Decaborano, 159 Decyl “tris” and parentheses used with, 110 Dehydro, 139, 146, 158, 208 Epit Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Formazano, 193 Formazanyl, 193 Formic acid, 183 anhydrides, 179 order of precedence of, 106 replacement analogs, 183 formyl, 220 Formyl, 134, 173 Formyl isocyanate, 183 Free radicals, 187 cationic, 184 Friedo, 212 Fructose, 208 valine deriv., 202 Fullerenes, 163A Fulminic acid, 188, 219 Functional compounds described by suffixes, 164-177 Functional derivatives of acids, 169 of amino acids, 205 commas between names of, 108 locants for, 119 order of citation of, 113 retrospective index searching for, 250 of stereoparents, 202, 204 of steroids, 286 Functional parent compounds, 130, 131 acids, order of precedence of, 106 Functions order of precedence of, 106 Furan, 146 in fused systems, 149, 151 Furandione polymers containing, 222 Furandiylidene, 161 Furanimine, 185 Furanium compounds, 184 Furano, 154 -furanose, 208 Furanosides, 208 Furazan, 281 Furostan, 211 Furylium compounds, 184 Fused ring systems, 147, 148 Fused systems base components for, 148, 149, 150, 281 boron-containing, 159 bridged, 154 carbocyclic, 148, 151 heterocyclic, 149, 151, 281 numbering of, 152 replacement nomenclature for, 153 Galactitol, 208 Galactose, 208 Gammacerane, 212 Gastrin, 206 Geometry of coordination complexes, 203 Germanamine, 199 Germanate, 215 Germane, 143, 199, 219 Germanium compounds, 199 cyclic, 146, 194 order of precedence of, 106 Germanium hydroxide, 199 Germaselenanes, 144 Gibbane, 212 Glucagon, 206 Glucitol, 208 gluco, 208 Gluconoyl chloride, 208 Glucopyranose, 208 Glucopyranosyl, 208 Glucopyranosylamine, 208 Glucopyranuronic acid, 208 Glucose, 208 mixtures containing, 221 polymers, 222 Glucosides, 208 Glucuronan, 208 Glutamic acid, 205 peptides containing, 206 Glutamoyl, 205 Glycerides, 185 glycero, 208 Glycerol esters, 185 146 Epithio, 154, 208 Epoxides oxirane names for, 166 Epoxy, 154, 211 Ergocalciferol, 224 Ergostane, 211 erythro, 108, 208 Ester-anhydrides, 186 Esters, 185. See also Functional derivatives of amino acids, 205 anions of, 180 of carbohydrates, 208 of halogen oxo acids, 188 of hetero-atom-attached hydroxyl groups, 175 as modification terms, 112, 113 of polyalkylene glycols, 222 retrospective index searching for, 247 of stereoparents, 202 of thio acids, 200 η(eta) for pi-bonded ligands, 215 -etane, 146 -ete, 146 Ethanamine, 131 Ethane, 130, 163 Ethanedinitrile, 172 Ethanedioic acid, 165 Ethanediol esters, 185 Ethanedione, 190 Ethanedithioic acid, 129 Ethane(dithioperoxoic) acid, 129 Ethanediyl, 125 Ethanethioamide S-oxide, 200 Ethanimidic acid, 165 Ethanimine, 177 Ethano, 154 Ethanol, 175 esters, 185 Ethanylylidene, 154 Ethenol polymers, 222 Ethenone, 174 Ethers, 196 “a” names for poly, 142 of polyalkylene glycols, 222 retrospective index searching for, 248, 271 Ethoxy elision in spelling of, 107 free radical, 187 Ethyl, 161 free radical, 187 Ethylene glycol polymers, 222 Ethylides, 201 Ethylium, 184 Ethyne metal derivs., 219 -etidine, 146 Eudesmane, 212 Ewens-Bassett numbers, 215, 219 in vitamin B12 names, 224 exo, 203 Farnoquinone, 224 Fermion, 217 Ferrates, 215 porphine complexes, 223 Ferrobyrinic acid, 224 Ferrocene, 215 order of precedence of, 271 retrospective index searching for, 264 Fibers synthetic, 222 Fibrinopeptide B, 206 Fluoresceins, 216 Fluorimide, 219 Fluorine compounds, 117, 188 Fluorocarbons locants for, 117 Fluoroselenious acid, 219 Formaldehyde, 183 oximes, 195 polymers, 222 Formamide, 183 Formamidine, 234, 280 Formazan, 193 retrospective index searching for, 249 Glycine, 205 peptides containing, 206 Glycols polymers, 222 Glycolic acid, 167 Glycosides, 208, 240 Glycosylamines, 208 Glycosyl halides, 208 Glycosyl radicals, 208 in nucleosides and nucleotides, 210 Glycyl, 205 Gonane, 211 Gonatriene, 211 Gorgostane, 211 Graft polymers, 222, 277 Gramicidin S, 206 Graphite, 219 Graphite nitrate, 219 Graphitic acid, 219 Greek letters alphabet, 310 order of citation of, 113 Guanidine, 183 derivs., retrospective index searching for, 251 Guanine, 122 Guanosine, 210 Guanylic acid, 210 polymers, 222 gulo, 208 Gutta-percha, 222 H. See Added hydrogen; Indicated hydrogen Hadron, 217 Hahnium, 219 Halides. See also Acid halides of germanium, lead, etc., 272 of metals, 219 of silicon, 282 Halogen compounds, 188 Halogenoid compounds, 188 Halogens, 219 Hantzsch-Widman system, 146 order of precedence of, 138 Helium-group gases, 219 Hematin, 223 Hemi, 192, 265A, 311 Hemiacetals of carbohydrates, 208 Heptene polymers, 222 Hetero-atom chains acyclic, 142 acyclic, radicals from, 161 heterogeneous, 144 homogeneous, 143 homogeneous, breaking of, avoided, 138 Hetero atoms lowest locants for, 137 order of precedence of compds. containing, 106, 138 Heterocyclic compounds fused, 149, 281 numbering of, 152 spelling of names of, 107 order of precedence of, 106 preferred to carbocycles, 138 Heterogeneous hetero chains, 144 Heteropoly acids, 219 Hetero polyboranes, 160 Hetero units, 127, 176, 196, 279 Hexaborane, 159 Hexadiene, 141 Hexanedioic acid polymers with diols, 222 Hexapropylene glycol, 222 Hexene polymers, 222 Hexodialdose, 208 Hexopyranosulose, 208 Hexoses, 208 Hexosulofuranose, 208 Hexosulose, 208 Hexulose, 208 Hexyne, 141 Histidine numbering of, 205 Homo, 204, 211 Homocysteine, 205 Homogeneous hetero chains, 143 147 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Hydrolytic polymers, 222, 277 Hydroperoxides, 126, 196 of elements, 219 order of precedence of, 106 Hydroperoxo, 219 free radical, 187 Hydroperoxy, 196 Hydrotrioxides, 196 Hydrotrioxo, 219 Hydrotrisulfides, 200 Hydroxamic acids, 167, 228 Hydroxides inner salts, 293A inorganic, 219 Hydroximic acids, 167, 228 Hydroxyl, 219 free radical, 187 hetero-atom-attached, 163, 175 Hydroxylamine, 193, 219 0-acyl, 171 N-alkyl and N-aryl, 176 N-alkylidene—see Oximes derivs., retrospective index searching for, 253 order of precedence of, 106 Hydroxylaminesulfonic acid, 193, 195 Hydroxylase, 218 Hypernuclei, 217 Hyperon, 217 Hyphens, 108 in hydroperoxide names, 126 Hypoboric acid esters, 182, 185 Hypochlorous acid, 188, 219 Hypofluorous acid, 188 Hypoiodous acid anhydrides, 188 Hyponitric acid, 219 Hyponitrous acid and metal salts, 219 Hypophosphoric acid, 197, 219 -ian in mineral names, 219 -ide, 219 ido, 208 Illustrated structural diagrams, 135 for stereoparents, 204, 211 Imidamides, 171 N-hydroxy, 171 radicals from, 134 retrospective index searching for, 234 tautomerism of, 122 Imidazole, 146 Imidazolidine, 146 Imides, 191 of arsenic and phosphorus acids, 197 oxides, 268 Imidic acids, 129, 183, 228 amides preferred to, 122 radicals from, 134 tautomerism of, 122, 165 Imido, 215 Imidodicarbonic acid, 129 Imidodiphosphoric acid, 197, 219 Imidodiselenic diamide, 219 Imidodisulfuryl fluoride metal salts, 219 Imidogen, 187 Imidosulfamic acid, 219 Imidosulfamide, 129, 219 Imidosulfurous acid, 200 Imidotetraphosphoric acid, 219 Imidotriphosphoric acid, 129 -imine in fused systems, 154 Imines, 177 N-alkyl derivatives, 176 order of precedence of, 106 retrospective index searching for, 254 Iminio, 184 Iminium compounds, 184 Imino as bridge, 154 in multiplicative nomenclature, 125 as substituent, 177 in tautomers, 122 Iminodiimidotriphosphoramide, 219 Iminomethyl, 168, 177 -in, 146, 149 Ions Homoglycans, 208 Homonorpregnane, 211 Homonorursene, 212 Hormones, 206 Hydantoin, 122 Hydrates, 192, 265A, 311 citation in modification, 113 labeled, 220 of metal salts, 219 Hydrazi, 161, 211 Hydrazide as index parent, 180, 219 Hydrazides, 189. See also Functional derivatives of amino acids, 205 of arsenic and phosphorus acids, 197 of boron acids, 182 of elements, 219 Hydrazine, 143, 193, 219 acyl—see Hydrazides alkylidene—see Hydrazones alkylthio, 189 boryl, 182 derivs., 189, 193 derivs., retrospective index searching for, 252 order of precedence of, 106 Hydrazinecarbothioamide derivs., 190 Hydrazinecarboxamide derivs., 193, 202 Hydrazinecarboxylic acid, 183, 189, 193 Hydrazinedicarboxylic acid, 165 Hydrazinedisulfonyl dichloride, 219 Hydrazinium, 184, 219 Hydraziniumyl, 184 Hydrazino, 161, 189, 193 tautomerism of, 122 Hydrazinosulfonyl, 189 Hydrazinylylidene, 161, 193 Hydrazo, 161, 193 Hydrazoic acid, 219 Hydrazonamides, 171 Hydrazones, 190. See also Functional derivatives of carbohydrates, 208 of stereoparents, 204 tautomerism of, 122 Hydrazonic acids, 165, 169, 190 hydrazides, 122 tautomerism with hydrazides, 165 Hydrazono, 161, 190, 193 Hydrazyl, 187 Hydride as index parent, 219 Hydrides, 219 labeled, 220 Hydriodic acid, 219 Hydro abnormal-valency ring systems, 158 locants for, 117 Hydrobromic acid, 219 Hydrocarbons acyclic, 141 fused systems, 148, 152 labeled, 220 monocyclic, 145 monocyclic, radicals from, 161 order of precedence of, 106 polycyclic, 147 spiro, 156 Hydrochloric acid and dimer, 219 Hydrochlorides, 198 Hydrocyanic acid, 183 Hydrodisulfides, 200 Hydrofluoric acid, 219 Hydrogen added—see Added hydrogen indicated—see Indicated hydrogen isotopes of, 220 in partial ester names, 185 subtraction of, from ring systems, 139 Hydrogenase, 218 Hydrogenobyrinic acid, 224 Hydrogen peroxide, 219 Hydrogen sulfide, 219 Hydrogen triiodide, 219 Hydrogen trioxide, 219 Hydroisocyanic acid, 219 Indefinite compounds, 120 cationic, 184 coordination compds., 215 Indene, 135 Index names choice of, 101, 103, 105, 138 with functional suffixes, 164-177 inversion of, 104 preferred, definition of, 192 retrospective searching of, 225-293 structural diagrams from, 312-318 Index name selection. See also Order of precedence CAS policies (previous and present) for, 255, 301 CAS policy revision for, 101, 255 for compds., 138 for fused ring systems, 151 necessity of rules for, 103 principles of, 105 for radicals, 133 Index parents definition of, 130, 164, 315 inversion of substituent prefixes at, 104 nonfunctional, molecular skeletons as, 140, 163 nonfunctional, order of precedence of, 106, 271 structural diagrams from, 312-318 Indicated hydrogen, 135, 317 in abnormal-valency ring systems, 158 to accommodate bridges, 154 ACS report on, 302 for cyclic ketones, 174 for cyclic sulfur compds. with abnormal valencies, 158 of fusion components, ignored, 152 lowest locants for, 122, 137, 138 present and former rules for, 256 in ring assemblies, 157 in spiro systems, 156 Indole analogs, 149 Indolylidene, 161 -ine, 146, 149 Inner salts, 112, 201, 224, 293A vitamin B12 derivs., 224 Inorganic compounds, 219 indexing policy changes for, 225, 239, 257, 273 labeled, 220 nomenclature of, history and development of, 306 nomenclature rules for, 298 Inosine, 210 Inosinic acid, 210 Inositols, 209 retrospective index searching for, 258 Inosose, 209 Insulins, 206, 274 Intermetallic compounds, 219 labeled, 220 International Mineralogical Association, 219 International Union of Biochemistry, 218 nomenclature rules of, 296-297 International Union of Pure and Applied Chemistry, 101, 219 nomenclature rules of, 296-300 Inversion of index names, 104 Iodate dichloro, 219 Iodic acid, 219 Iodine as index parent, 188 Iodine acids, 219 anhydrides, 188 Iodine compounds with abnormal valencies, 259 addition compds., 192 cyclic, 158 retrospective index searching for, 259 Iodonium, 184 Iodyl, 188 Ion(1-) as modification term, 113, 198 Ions complex, 215 inorganic, 219 negative, 180 Ions Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Lactoyl in peptides, 206 Ladder polymers, 222 Lakes, 216 λ (lambda) in heterocyclic ring systems, 158 Langham, Cecil C., 102 Lanostane, 212 Latin prefixes, 311 Lead compounds, 199 cyclic, 158 monocyclic, 146 order of precedence of, 106 Lepton, 217 Leptonic molecules, 217 Letter locants in coordination names, 215 in labeled compds., 220 order of citation of numerals and, 114 Leucomycin V, 202 Ligands, 215, 242 Like treatment of like things, discontinuance of, 138, 255 Linearity of bridged fused systems, 154 of fused systems, 138, 150 Line formulas with binary names, 219 for carbonic anhydride sulfur analogs, 183 containing isotope symbols, 220 for inorganic compds., 219, 257, 315 with polyphosphorus acids, 197 synonym line formulas, 109, 129 Lipids IUPAC-IUB tentative rules for nomenclature of, 297 Lithian, 219 Lithio, 215 Lithium compounds organic, 194 Locants, 114 all cited when one is needed, 117, 119 in “a” names, 128 effect on alphabetization, 121 for bridged fused systems, 154 capital italic letters, in coordination nomenclature, 215 enclosing marks between like, 132 in ester names, 185 for functional derivs., 119 for fused systems, 115, 152 for indefinite compds., 120 for isotopes, 220 lowest, definition of, 137 lowest, principle of, 255 in modifications, 185 for molecular skeletons, 137, 138 in multiplicative nomenclature, 118 present and former rules for, 263 primed, 114, 151, 152 in radicals, 116, 133 in rings and chains, 137 for suffixes, 115 for sulfides of hetero atoms, 200 Lowest locants, 137, 255 for indicated hydrogen, 122, 135, 152 for multiple bonds, 138 in radicals, 133 in tautomers, 122 Lupane, 212 Lysozyme, 218 Macromolecular chemistry nomenclature of, history and development of, 307 nomenclature rules for, 299 Magnesate phorbine complexes, 223 Magnesium cations, 219 Magnesium compounds chlorophylls, 223 Malonic acid. See Propanedioic acid Manganese hydroxide oxide, 219 Manganic acid, 219, 273 Mannan, 208 Mannopyranosyl bromide, 208 Maximum substitution, 122, 133, 138 Melamine, 122 polymers with formaldehyde, 222 148 negative, in modifications, 198 negative, of elements, 219 order of citation of, in modifications, 113 positive, 184, 219, 270 -io radicals from metals, 215 -irane, 146 -irene, 146 -iridine, 146 -irine, 146 Iron compounds, 215, 219 hemes, 223 Iron oxide, 219 Iron zinc oxide, 219 Iso in boron-compd. names, 159 Isobenzofurancarboxylic acid, 186 Isobenzofurandione, 179 Isocyanates acid, 170 acid, order of precedence of, 106 Isocyanato, 183, 188 Isocyanides, 188 of arsenic and phosphorus acids, 197 retrospective index searching for, 260 Isocyano, 188 Isocytidylic acid, 210 Isoguanylic acid, 210 Isohypophosphoric acid, 197, 219 Isoindole in fused systems, 149, 151 Isoneuraminic acid, 208 Isopoly acids, 219 Isoselenazole, 146 Isosemicarbazones, 190 Isothiazole, 146 Isotopes, 220 in alloys, 214 compds. labeled with, 220 elementary particles, 217 of hydrogen, ACS report on, 302 metastable, 220 Isoxazole, 146 Italics, 108 -ite, 219 -itol, 208 IUB. See International Union of Biochemistry Ium compounds, 184, 215 borates, 201 retrospective index searching for, 270 salts, 198 zwitterionic, 201 -iumdiyl, 184 -iumyl, 184 IUPAC. See International Union of Pure and Applied Chemistry Kaurane, 212 Ketenes, 174 thio, 183 retrospective index searching for, 261 Keto-enol tautomers stereochemistry of, 203 Ketones, 174 added hydrogen in cyclic, 136 hetero-atom-attached, 163 indicated hydrogen in cyclic, 135 nitrogen-containing cyclic, 171 of nitrogenous heterocycles, 122 order of precedence of, 106 oximes, 195 retrospective index searching for, 262 Ketoses, 208 Kraystay K, 221 Kromycin, 202 Krypton fluoride, 219 L, 108, 205, 208, 209 Labeled compounds. See Isotopes Lactam-lactim tautomerism, 122 Lactams carbohydrates, 208 Lactate dehydrogenase, 218 Lactoflavine, 224 Lactones, 185 of amino acids, 205 of carbohydrate acids, 208 cyclic peptides, 206 steroidal, 211 Lactose, 208 Melanocyte-stimulating hormone, 206 Menthane, 212 Mercapto free radical, 187 hetero-atom-attached, 175 Mercury organic derivs., 194 Mercury chloride, 219 Meso-ionic compounds, 201, 293A Meson, 217 Mesonic atom, 217 Metaborates cyclic, 219 Metal complexes. See Coordination compounds Metal carbonyls, 215 Metallic compounds organo-, 194 monocyclic, 146 retrospective index searching for, 272 Metallocenes, 215 retrospective index searching for, 264, 271 stereochemistry of, 203 Metal-metal bonds, 203, 215 Metal oxides radicals from, 219 Metal radicals, 215 Metals, 215 complexes of, 215 definition of, 219 hydroxides and oxides, 219 isotopes, 217 Metal salts, 198 of amino acids, 205 Metaphosphinic acid, 197 Metaphosphoric acid, 197, 219 Metaphosphorous acid, 197 Methanamine, 176 boron complexes, 182 Methanaminium, 184 salts, 198 ylides, 201 Methane, 130, 140, 141 multiplication of, 118 Methanediimine, 177 Methane(dithioic) acid, 183 Methaneperoxoic acid, 183 Methanethial, 183 Methanethioamide, 183 Methanethione, 174, 183 Methanimidoyl isocyanate, 183 Methanimine, 183 Methano, 154 Methanoic acid replacement analogs, 183 Methanone, 174, 183 oximes, 195 Metheno, 154 Methines, 216 Methiodides, 184 Methoxides, 180 Methoxy, 107, 287 free radical, 187 Methyl, 161 free radical, 187 Methylene, 125, 161 parentheses around, 110 Methylethyl, 162 Methylides, 201 Methylidyne, 161 free radical, 187 Methylium, 184 Methyliumyl, 184 Methylthio free radical, 187 Methylphenyl, 162 Minerals, 219 labeled, 220 (−) (minus), 203 Mixed salts, 219 Mixtures, 221 of dyes, 216 order of citation of, in modifications, 113 retrospective index searching for, 265 of stereoisomers, 203 Modifications enclosing marks in, 109 format of, 104, 317 locants for terms in, 119 order of citation of terms in, 113 Molecular addition compounds, 192, 265A 149 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Nitrilio, 184 Nitrilo, 125 aci-Nitro, 193 Nitrogen acids, 219 Nitrogen compounds, 193 N-glycosyl derivs., 208 heterocyclic, N-acyl derivs., 171 monocyclic, 146 order of precedence of, 106 peptides as, 206 phosphorus-, 197 order of precedence of, 106 quaternary, 184, 270 salts, 198 tautomeric, 122 Nitrogen hydrides, 219 Nitrolic acids, 167, 228 Nitrone retrospective index searching for, 268 Nitrosamide, 219 Nitrosolic acids, 228 Nitrososulfonyl fluoride, 219 Nitrosyl, 219 Nitrosyl chloride, 219 Nitrosyl (disulfate), 219 Nitrosyls metal, 215 Nitrous acid, 219 anhydrides, 179 Nitroxide, 187 Nitryl, 219 NNO, 193 Nomenclature history of chemical, 303-308 IUPAC, IUB, and ACS rules of chemical, 296-300 retrospective index searching of CAS, 225 Nonfunctional compounds order of precedence of, 106 Nor, 139 in alkaloid names, 204 in peptide names, 206 in steroid names, 211 in terpene names, 212 Norcholenedioic acid, 211 Norlupane, 202 Normalization of tautomeric structures, 122, 184 Nucleon, 217 Nucleosides, 210 retrospective index searching for, 269 Nucleotides, 210 polymers, 222 retrospective index searching for, 269 Numbering. See also Locants of fused systems, 152 of molecular skeletons, 137 Numerals in alphabetization, 121 order of citation of letters and, 114 Nylon, 222 o elision of, 107 0, 108 17O, 220 -oan in mineral names, 219 -ocane, 146 Occurrences maximum number of parent, 122, 125, 138 -ocin, 146 -ocine, 146 Octaphene, 148 -oic acids, 165 -olane, 146 -ol, 175 -ole, 146 Oleanane, 212 -olidine, 146 Oligomers, 222 of arsenic and phosphorus acids, 197 of boranamines, 182 of carbohydrates, 208 clusters, 219 of nucleotides, 210 Oligonucleotides, 210 Oligosaccharides, 208 -onane, 146 -one, 174 Oxon See also Salts of amino acids, 205 of borane, 182, 239 citation in modification, 113 of polymers, 222 stereochemistry of, 203 of stereoparents, 202 Molecular skeletons, 140-163 boron, 159 definition of, 140, 315 as index parents, 130 numbering of, 137 order of precedence of, 106, 271 radicals from, 161 Molybdate iron sodium oxide, 219 Mono, 111, 120, 192, 311 in anhydride names, 179 in ester names, 185 Monoprotonated as modification term, 184 Morpholine, 146 Morpholinyl, 161 µ (mu), 215 in polyborane names, 182 muco, 209 Multiple bonds. See also Unsaturated compounds maximum number of, in parent radicals, 133 Multiplicative nomenclature, 125 brackets around parent in, 109 for ester names, 185 locants in, 118 for fused systems, 151 preferred, 138 retrospective index searching for, 255 ylidene radicals in, 125, 255 Multiplicative prefixes, 110, 311 alphabetization rules for, 121 present and former ruleo for, 266 Muonic molecule, 217 Muonium, 217 Muramic acid, 208 myo, 209 N, 108 order of citation of, in locant sets, 114 220 Name selection. See Index name selection Naphthacene numbering of, 152 Naphthalene in fused systems, 148, 151 numbering of, 137 Naphthalenedione vitamin K derivs., 224 Naphthalenimine, 154 Naphthaleno, 154 Naphthalenone added hydrogen in, 136 Natural products. See Stereoparents neo, 209 Neo in boron compd. names, 159 in terpene names, 212 Neogammacerane, 212 Neoonocerane, 212 Neuraminic acid, 208 Neutrino, 217 Neutron, 217 Nickelibyrinic acid, 224 Nielsbohrium, 219 Ninth Collective Index substance name revision in, 101 Niobate, 215 Nitramide, 219 Nitrate as index parent, 219 Nitric acid and metal salts, 219 Nitric acidium, 219 Nitrides of arsenic and phosphorus acids, 197 Nitrido, 215 Nitridotriphosphoric acid, 219 Nitriles, 172 of carbohydrate acids, 208 order of precedence of, 106 retrospective index searching for, 267 Nitrilimine, 172, 201, 267 15N, elision of “e” before, 107 -onin, 146 -onine, 146 Onium compounds, 184. See also Cations inner salts, 112, 293A present and former indexing rules for, 270 salts, 198 ylides, 201 ONN, 193 Ophiobolane, 212 Optical rotation. See Stereochemistry or, 120 Order of citation. See also Alphabetization of locants, 114 of modification terms, 113 of substituent prefixes, 121 Order of precedence of acids, 167 of arsenic and phosphorus acids, 197 of base components in ring systems, 148, 281 of carbonic acid and related compds., 183 of cations, 184 of compd. classes, 106 in index name selection, 105 present and former, 271 of ring systems, 138 of silicon compds., 106, 199 Organic chemistry nomenclature of, history and development of, 304 nomenclature rules for, 296 Organic hetero chains, 142 Organometallic compounds, 194 monocyclic, 146 retrospective index searching for, 272 Orientation. See also Linearity of fused ring systems, 152 Orotidylic acid, 210 Ortho acids esters, 185 Ortho-fusion, 148 Ortho-peri fusion, 148 Osazones, 190 -osyl, 208 Oxa, 128 “Oxa-aza” nomenclature. See Replacement nomenclature Oxadiazolidinone, 201 Oxaspirodecane, 156 Oxatetragermolane, 146 Oxathiaazabicyclohexane, 155 Oxathiadisilaoctane, 142 Oxathiolane, 146 Oxatricycloheptane, 155 Oxazole, 146 Oxetane, 196 Oxetanone, 196 Oxidase, 218 Oxides. See also Additive terms of amides and imides, 268 of amines, 176 of azo compds., 193 of cyclic nitrogen and sulfur compds., 158 of cyclic phosphorus compds., 185 of cyclic sulfur compds., 171, 179 of elements, 219 of hetero atoms, 158 locants for, 119 of nitrogen atoms, 113, 176, 193, 268 of phosphorus compds., 175 of thioacids, thioamides and thiones, 200 of thio esters, 185 Oximes, 195. See also Functional derivatives of amides, 171 of carbohydrates, 208 of stereoparents, 204 tautomerism of, 122 Oxirane, 196 polymers, 222 Oxirene, 146 Oxirenol and derivs., no locants used with, 117 Oxireno systems, 281 Oxo, 174 in terminal positions, 173 Oxo acids. See Acids Oxonia, 184 Oxonium chloride, 219 Oxonium compounds, 184 Oxy Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 amino derivs., 216 Phenothiazinium, 184 Phenoxasilin, 149 Phenoxazine amino derivs., 216 Phenoxide, 180 Phenoxy elision in spelling of, 107 Phenylalaninamide, 206 Phenylalanine, 205 peptides containing, 206 Phenylalanyl, 205 Phenylazo, 131 Phenylene, 125 Phenylenedicarbonyl, 168 Phenylsulfinyl free radical, 187 Phenylsulfonyl, 168 Phenylthio, 168 Phorbine, 223 Phospha, 128 Phosphaborocine, 182 Phosphatase, 218 Phosphate, 180 as index parent, 219 as modification term, 180 Phosphazines, 190 Phosphenic acid, 197 Phosphenimidous chloride, 197 Phosphenous acid, 197 Phosphide as modification term, 180 Phosphides of elements, 219 Phosphido, 215 Phosphine, 130, 143, 197 order of precedence of, 106, 271 Phosphinecarboxylic acid, 197 Phosphine imide, 197 order of precedence of, 106, 271 Phosphine oxide, 197 order of precedence of, 106, 271 Phosphine sulfide, 200 order of precedence of, 106, 271 Phosphinic acid, 197 Phosphinic cyanate, 179 Phosphinidene, 161 Phosphinidyne, 161 Phosphinimine, 177 Phosphino, 161, 197 free radical, 187 Phosphinyl, 197 Phosphinothioyl, 197 Phosphinous acid, 197 Phosphonate, 180 Phosphonia, 184 Phosphonic acid, 197 anhydrides, 179 Phosphonium, 184 inorganic, 219 mercury derivs., 194 salts, 198 ylides, 201, 276 Phosphonium cyanide, 219 Phosphonocyanatidic acid, 179 Phosphonous acid, 197 Phosphorane, 143, 197 order of precedence of, 106, 271 and phosphonium ylides, 201 Phosphoranyl, 161 Phosphoric acid, 197 anhydrides, 179 esters, 185 inorganic salts, 219 replacement names from, 129 Phosphorin, 146 Phosphorochloridic acid, 129 Phosphorodiamidic acid, 197 Phosphorodithioic acid esters, 185 Phosphorothioic acid esters, 185 Phosphorothioic triamide, 129 Phosphorous acid, 197, 219 esters, 185 Phosphorous trichloride, 197 Phosphorus(1+), 215 Phosphorus acids, 197, 219 anhydride-esters, 186 anhydrides, 179 150 Oxy, 125 free radical, 187 Oxygen compounds, 196 monocyclic, 146 order of precedence of, 106 Oxytocin, 206 Ozonides, 192 of elements, 219 P-, 108, 219 Papain, 218 Pantothenic acid, 224 Paraformaldehyde, 222 Parent compounds, 130 Parentheses, 109 around compound radicals, 132 Particle resonances, 217 Pectic substances ACS report on nomenclature of, 302 Penicillins stereochemistry of, 203 Pentaborane, 159 Pentacene, 148 Pentacyclooctasiloxane, 155 Pentalene, 148 Pentanedioic acid, 165 Pentaoxaheptadecanediol, 222 Pentasilane, 143 Pentazadienyl, 161 Pentoses, 208 Pentuloses, 208 Pentyloxy, 132 Peptides, 206, 222 “a” names not used for, 127 IUPAC-IUB tentative rules for nomenclature of, 297 retrospective index searching for, 274 Perchlorato, 215 Perchloric acid and ammonium salt, 219 esters, 185 Perchloryl, 188, 219 Perhalic acids, 188 Periodic acid, 219 Periods in spiro and Von Baeyer names, 108 Permanganic acid, 219, 273 Peroxides, 126, 131, 196 carboxy, 179 of elements, 219 order of precedence of, 106 retrospective index searching for, 275 Peroxoic acids, 165 Peroxy acid halides, 170 Peroxy acids, 165 of arsenic and phosphorus, 197 from carbonic acid, 183 esters, 185, 196 inorganic, 219 order of precedence of, 106, 167 retrospective index searching for, 271, 280 of sulfur, 200 Peroxychromic acid, 219 Peroxydicarbonic acid, 183, 219 Peroxydicarbonic difluoride, 196 Peroxydiphosphonic acid, 196 Peroxydiphosphoramide, 219 Peroxydisulfuric acid, 219 Peroxyhypofluorous acid esters, 196 Peroxymonosulfuric acid, 219 Perylene in fused systems, 148, 151 Phenanthrene anthracene preferred to, 138 numbering of, 152 Phenazine, 149 amino derivs., 216 Pheno, 149 Phenol polymers with formaldehyde, 222 Phenolphthalein, 216 Phenols, 175 Class I, 185 metal salts, 198 order of precedence of, 106 retrospective index searching for, 229, 271 salts, 198 Phenolsulfonephthalein, 216 Phenothiazine inorganic, and salts, 219 nucleotide esters, 210 replacement names for, 129 salts, 198 Phosphorus compounds, 197 monocyclic, 146 order of precedence of, 106, 271 retrospective index searching for, 276 spiro, abnormal valency in, 158 tautomeric, 122 Phosphoryl, 276 Phosphoryl chloride, 276 Phthaleins, 216 Phthalocyanine, 223, 278 copper complex, 215 Phylloquinone, 224 Physicochemical units manual of, 300 Pi-bonded ligands, 215 Picrasane, 202 Picrates, 180, 192 Pigments organic, 216 Pinane, 212 Piperazine, 146 Piperazinium, 184 Piperidine pyridine preferred to, 138 Platinum metals, 219 Plumba, 158 Plumbane, 143, 199 iodo derivs., 219 Plumboxanes, 199 (+) (plus), 203 Plutonyl ion, 219 Polyalkylene glycols, 222 Polyamides “a” names for, 171 fibers, 222 Polyboranes, 159 hetero, 160 radicals from, 161 Polycyclic systems, 147. See also Ring systems Poly(dioxobutanediyl), 222 Polyesters, 222 Polyethylene glycols, 222 Polymers, 222 of amino acids, 206 “a” names not used for, 127 of carbohydrates, 208 of coordination compds., 215 nomenclature of, history and development of, 307 order of citation of, in modifications, 113 retrospective index searching for, 277 stereochemistry of, 203 structural diagram derivation for, 315 Poly(methylene), 220 Polynucleotides, 222 IUPAC-IUB recommendations for nomenclature of, 297 Poly(oxyethanediyl), 222 Poly(oxymethylene), 222 Polyphenyls, 157 branched, 163 functional derivs., 163 radicals from branched, 162 radicals from unbranched, 161 Polypropylene glycols, 222 Polysaccharides, 208 Polysulfides, 200 order of precedence of, 106 Polyvalent radicals in multiplicative names, 125 Porphine, 223 Porphyrazine, 223 Porphyrins, 223 retrospective index searching for, 278 Positron, 217 Positronium, 217 Potassium phosphate sulfate, 219 P,P ′ , 219 Precedence order of—see Order of precedence Preferred index names definition of, 192 Prefixes miscellaneous, 309 multiplicative—see Multiplicative prefixes 151 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Quark, 217 Quater, 157 Quaterphenyl radicals from, 162 Question marks, 120 Quinoline analogs, 149 Quinolinium, 184 Quinolizinium, 184 Quinoxaline in fused systems, 149, 151 Quinquephenyl, 157 radicals from, 162 R, 203, 212 Radical ions, 180 Radicals. See Free radicals; Substituent prefixes Radicofunctional nomenclature, 126 Ratios in addition-compd. names, 192 in anhydride names, 179 in ester names, 185 Rayon, 222 Reductase, 218 Replacement nomenclature for acids, 165 for acyclic skeletons, 127, 140, 142 for amides, 171 for amines, 176 for anhydrides, 179 for arsenic and phosphorus acids, 197 for boron compds., 182 for cations, 184 in cocarboxylase names, 224 for esters, 185 for ethers and peroxides, 196 for functional groups, 129 for fused systems, 149, 153 for hetero chains, 142, 144 for heterosteroids, 211 for hydrazides, 189 for ketones, 174 lowest locants in, 137 for minerals, 219 prefixes for, 128 present and former rules for, 279, 280 for radicals, 133, 161, 287 for silicon (etc.) compds., 199 for spiro systems, 156 for sulfur compds., 200 for urea derivs., 183 for Von Baeyer systems, 155 Replacement prefixes, 128 elision of “a” in, 146 Resonance-stabilized compounds anions, 180 cations, 184 phenazine and phenothiazine amino derivs., 216 Retinoic acid, 212 Retinol, 212 retro, 206, 211, 212 Retrocarotenes, 212 Retrospective searching for index names, 225-293 Retrosteroids, 211 Ribitol, 208 riboflavin deriv., 224 ribo, 208 Riboflavin, 224 Ribofuranosyl, 210 Ribonic acid, 208 Ribonuclease A, 207 Ribose, 208 Ring assemblies, 147, 157, 266, 281 added hydrogen in, 136 indicated hydrogen in, 135 locants for, 114 punctuation for, 109 radicals from, 161, 287 retrospective index searching for, 281 Ring contraction in alkaloids, 204 in steroids, 211 in terpenes, 212 Ring expansion in alkaloids, 204 in steroids, 211 in terpenes, 212 Semi substituent—see Substituent prefixes Pregnane, 211 and derivs., stereochemistry of, 203 Pregnenedione mixtures containing, 221 Primary components in fused systems, 151 Primed locants, 114 in fused systems, 151, 152 Principal chemical groups, 104, 164-177 esters of, 185 hetero-atom-attached, 163 lowest locant for, 137 as suffixes, 131 Proline, 205 salts, 202 Pronunciation of chemical words, ACS report on, 302 Propadiene, 141 Propanamine, 176 Propanebis(thioic) acid, 165 Propanedioic acid anhydride-esters, 186 anhydrides, 179 cyclic esters, 185 esters, 185 hydrazides, 189 Propanesulfonic acid, 131 Propanetriol esters, 185 Propanimine, 177 Propanoic acid, 131, 165 anhydrides, 179 Propanone, 174 hydrazone, 190 retrospective index searching for, 262 Propene(dithioic) acid, 165 Propenoic acid polymers containing, 222 Propenol, 141 Propoxide, 180 Prostaglandins, 202 Prostane, 202 Proteinases, 218 Proteins, 207 enzymes, 218, 246 Proton, 217 Punctuation, 108 Purinamine derivs., 210 glycosyl, 208 Purine nucleoside and nucleotide derivs., 210 numbering of, 152 tautomeric derivs. of, 122 Purinium, 184 Purinone derivs., 210 Pyran, 135, 146 Pyranone, 135, 136 Pyranoses, 208 Pyranosides, 208 Pyrazine, 146 Pyrazole, 146 tautomeric derivs., 122, 180 Pyrazolidine, 146 Pyrene numbering of, 152 Pyridazine, 146 Pyridine, 146 preferred to piperidine, 138 Pyridinecarboxamide, 224 Pyridinium, 184 acyloxy derivs., 185 ylides, 201 Pyridinone hydrazones and oximes, 122 Pyridinyl, 161 Pyridoxal, 224 Pyridoxamine, 224 Pyridoxol, 224 Pyrimidine, 146 nucleoside and nucleotide derivs., 210 tautomeric derivs., 122 Pyrindine, 281 Pyrophosphoric acid, 197, 273 Pyrrole, 135, 146 Pyrrolidine, 135, 146 Pyrylium, 184 Ring-size descriptors, 108 Ring systems additional index entries for, 138, 163, 281 base components of fused, 150, 281 bridged fused, 154 carbocyclic fused, 148 with functional side chains, 124 fused steroidal, 211 heterocyclic, 199 arsenic- and phosphorus-containing, 197 cyclic esters named as, 185 fused, 149 imides named as, 191 oxygen-containing, 196 indicated hydrogen in, 135 locants for, 137 metal-containing, 194 monocyclic hetero, 146 monocyclic hydrocarbon, 145 nitrogenous, N-acyl derivs., 171 order of precedence of, 138 polycyclic, 147 preferred to acyclic skeletons, 138, 271 radicals from, 161 replacement names for fused, 153 retrospective index searching for, 281 Von Baeyer, 155 Roman letters as locants, order of citation of, 114 Rotaxanes, 192 Rubber, 222 s, 108 S, 203, 212 35S, 220 SIV, 140, 158 Saccharides, 208 in nucleosides and nucleotides, 210 Salamandra alkaloids, 211 Salt-type parents, 219 Salts, 198. See also Molecular addition compounds of amino acids, 205 of cations, 180 citation of, in modifications, 113 common anions of, 198, 281A double and mixed, 219 of germanium, lead, and tin, 199 inorganic, 219 locants not used for, 119 of stereoparents, 202 Sanbornite, 219 Schiff bases, 176 scyllo, 209 Searching retrospective, for index names, 225-293 Seco, 204, 212 Secocholestanol, 211 Secocholestatrienol, 224 Secoergostatetraenol, 224 Secostrychnidinoic acid, 204 Selection of index names—see Index name selection Selenals, 173 order of precedence of, 106 Selenic acid, 219 Selenic diamide, 219 Selenides, 200, 271 di and poly, order of precedence of, 106 of elements, 219 Seleninic acids, 165 Selenious acid, 219 Selenium compounds, 200 order of precedence of, 106 Seleno, 200 Selenols, 175 order of precedence of, 106 Selenonic acids, 165 Selenonyl chloride, 219 Selenophene, 146 Selenosulfuric acid, 129 Selenotelluroarsenious acid, 219 Selenoxo, 174 Selenyl, 219 free radical, 187 Selones, 174 order of precedence of, 106 Semicarbazones, 190 of stereoparents, 202 Semi Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Stannoxanes, 199 Starch, 208 Steel, 214 Stereochemical descriptors, 203, 284, 318 for alkaloids, 204 for amino acids and peptides, 205, 206 for carbohydrates, 208 chirality symbols, 203 for inositols, 209 for polymers, 222 for steroids, 211 for terpenes, 212 Stereochemistry, 202-212, 284, 318 ACS reports on, 302 assumptions, 205 of biline, 223 at double bonds, reports on, 301, 302 of inositols, 209 IUPAC tentative rules for, 296 of octahedral inorganic compds., IUPAC tentative proposals for, 298 of polymers, IUPAC nomenclature report on, 299 present and former rules for, 284 Stereoparents, 101, 202-212, 285, 318 addition compds. of, 192 copolymers, 222 definition of, 202 mixtures containing, 221 midified stereochemistry cited for, 203 present and former indexing rules for, 285 Steroids, 211 with modified stereochemistry, 203 retrospective index searching for, 286 Stibinamine, 181 Stibine, 143, 181 boryl derivs., 182 Stibine oxide, 181 Stibine sulfide, 181, 200 Stibino, 161, 181 Stibole, 181 Stibylene, 161 Stigmastane, 211 Stock numbers, 219 in vitamin B12 names, 224 Streptamine, 209 Structural diagrams, 135 in CA indexes, 315 derivation from index names, 312-318 Structural repeating units, 222 Strychnidine, 204 Subdivisions of large index headings, 104 Substituent prefixes, 161, 294, 316 from acids-see Acid radicals alphabetic list of, 294 “a” names for, 128 cationic, 184 compound and complex, 133, 162 elision in, 283 enclosing marks for, 109 ester groups as, 112 functional groups expressed as, 250 inversion of, 104 locants for, 117 locants in, 116 lowest locants for, 137 maximum number of, 122, 133, 138 from metals, 215 multivalent, as structural repeating units, 222 order of citation of, 121 polyvalent, in multiplicative names, 125 present and former rules for, 287 from steroids, 211 Substituent suffixes, 131 locants for, 115 order of precedence of, 106 principal groups as, 131, 164-177, 315 Substitutive nomenclature, 130, 139, 164 Substitutive parent compounds, 130 Subtractive nomenclature, 139 Succinic acid. See Butanedioic acid Sucrose, 208 Suffixes. See Substituent suffixes Sugars. See Carbohydrates Sulfamic acid, 219 as elided name, 107 metal salts, 219 152 Semicolons, 108 Semioxamazones, 190 Septanoses, 208 Sequence rule, 203 Sesqui, 192, 265A, 311 Sigma-bonded ligands, 215 Sila, 128 Silabenzene, 146 Silacyclopentane, 199 Silacyclopropane, 146 Silanamine derivs., 144, 176 multiplication of, 118 N-silyl, 199 Silane, 143, 199 acyl derivs., 163 order of precedence of, 106 polymers, 222, 277 tetrachloro, 257 Silano, 154 Silanol, 175, 199 multiplication of, 118 Silathianes, 199, 282 Silazanes, 144, 146, 199 Spiro systems, 156 Von Baeyer systems, 155 Silica, 219 Silicic acids, 199, 282 Silicide as index parent, 180 Silicon compounds, 199, 282 “a” names for acyclic, 142 fused systems, 149 monocyclic, 146 order of precedence of, 106 polymers, 222, 277 retrospective index searching for, 282 Von Baeyer systems, 155 Siloxanes, 144, 199 cyclic, 146 polymers, 222, 277 ring assemblies, 157 Spiro systems, 156 multiplicative radicals from, 125 Von Baeyer systems, 155 Silylene free radical, 187 Silylidyne, 161 Sodio, 215 Sodium chloride, 219 labeled, 220 mixtures containing, 221 Sodium chloride sulfate, 219 Sodium hydride, 219 Sodium oxide, 219 Sodium peroxide, 219 Solanidane, 211 Solanidenol, 211 Solanidine, 211 Solasodine, 211 Solid solutions of inorganic compds., 219 Solvates, 192 Spaces in uninverted names, 108 Species names for peptides, 206 Spelling, 107 present and former rules for, 283 Spirobi, 156 Spirohexasiloxane, 156 Spirooctane, 156 Spirosolane, 211 Spirostan, 211 Spiro systems, 140, 147, 156 added hydrogen in, 136 cationic, 184 indicated hydrogen in, 135 punctuation in names of, 108, 109 radicals from, 161 steroidal, 211 SRUs, 222 Stainless steel, 214 Stannane, 130, 143, 199 Stannanetetrayl, 161 Stannate dipotassium, 219 Stannathianes, 144 Stannazanes, 144 Sulfamide, 219 derivs., 219 as elided name, 107 Sulfanilic acid, 167 Sulfato, 215 Sulfenic acids, 165 esters, 196 Sulfenoselenoic acids, 200 Sulfenothioic acids, 165, 188, 196, 200 Sulfides, 200, 271 of elements, 219 di and poly, order of precedence of, 106 of hetero atoms, 158 of nitrogen and phosphorus compds., 200 retrospective index searching for, 288 Sulfilimine, 200 Sulfimide, 200, 219 Sulfinic acids, 165 Sulfinimidic acids, 165, 200 Sulfinyl, 168, 200, 219 Sulfinylamino, 200 Sulfinylsulfonyl, 200 Sulfonamides, 171 Sulfonefluorescein, 216 Sulfonephthaleins, 216 Sulfones retrospective index searching for, 289 di and poly, order of precedence of, 106 Sulfonic acids, 165 acyclic with cyclic substituents, 166 anhydrides with inorganic acids, 219 esters, 185 free radicals from, 187 order of precedence of, 106, 167 Sulfonimidic acids, 165 Sulfonimidoyl, 200 Sulfonium, 184, 219 ylides, 201 Sulfoniumyl, 184 Sulfonohydrazonic acids, 165 Sulfonohydrazonimidic acids, 129 Sulfonothioic acids esters, 200 Sulfonyl, 168, 200, 219 Sulfonyl halides, 170 Sulfonyloxy in free radical names, 187 Sulfoxides, 200 retrospective index searching for, 289 Sulfoximine, 200 Sulfoxylic acid, 219 selenium analogs not recognized, 219 Sulfur coordination complexes, 131, 200 tetravalent, in ring systems, 140 Sulfur acids, 219 order of precedence of, 106 Sulfur compounds, 200 cyclic, with abnormal valencies, 158 dyes, 216 retrospective index searching for, 288 thio carbohydrates, 208 Sulfur diimide, 106, 200 Sulfur dioxide, 219 Sulfuric acid, 219 ammonium iron salt, 219 anhydrides, 179 esters, 185 and metal salts, 219 uranium complex, 219 Sulfurous acid, 219 monosodium salt, addition compds., 192 Sulfur oxides, 219 Sulfur trilmide, 200 Sulfur trioxide, 219 Sulfuryl, 219 Sulfuryl chloride, 219 Superoxides of elements, 219 Superoxido, 215 Superscripts abnormal valency indicated by, 158 in Von Baeyer names, 155 Superscripts, 114, 137 Sydnones, 201, 293A syn, 203 Synonym line formulas. See Line formulas Synthetic fibers, 222 System indicators 153 Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Thiodiphosphoric acid, 219 Thiohydroperoxides, 129, 196 Thiohypochlorous acid anhydrosulfides, 170, 188 Thiohydroxylamine, 129 order of precedence of, 106 Thioic acids, 129, 165 Thiols, 175 Class I, 185 order of precedence of, 106 retrospective index searching for, 291 Thiometaphosphimic acid, 197 Thiomorpholine, 146 Thiones, 174 order of precedence of, 106 S-oxides, 200 thiono, 108 Thionyl, 219 Thionyl chloride cyanide, 219 Thionyl imide, 200 Thioperoxides, 129, 196 Thioperoxy acids esters, 185 Thioperoxydicarbonic acid, 183 Thioperoxydicarbonic diamide, 200 Thioperoxydiphosphoric acid, 197, 219 Thioperoxydiphosphoric tetrafluoride, 200 Thioperoxymonosulfuric acid, 219 and esters, 200 Thiophene, 146 abnormal valency in, 158 Thiophene-ol, 175 Thiopheniumyl, 184 Thiophosphoryl chloride, 276 Thiosemicarbazones, 190 Thiosilicic acid, 199, 219 Thiosulfuric acid anhydrosulfides, 200 Thiosulfuric acidium, 219 Thiosulfurous acid, 219 Thiosulfuryl chloride, 219 Thiotrithiazyl, 219 Thiourea, 129, 183 Thioxanthene, 149 Thioxo, 131, 174 in terminal position, 173 Thioxomethyl, 134, 173, 174 Thorium hydride iodide, 219 threo, 208 Thromboxane, 202 Thymidine, 210 Thymidylic acid, 210 Tin chloride, 219 Tin compounds, 199 cyclic, 139 monocyclic, 146 order of precedence of, 106 Titanyl, 219 Tocopherols, 224 Tomatidlne, 211 Trade names for polymers, 222 trans, 203 Transition metals, 219 amino acid salts of, 205 Tri, 110 Triazane, 143, 193 order of precedence of, 106 Triazanium, 184 Triazanyl, 161 Triazatriphosphorine, 158, 197 Triazenyl, 193 tautomerism of, 122 Triazinetriamine polymers with formaldehyde, 222 Tribismuthine, 181 Triborane, 159 Trichlorodiphosphoric acid, 219 Trichothecane, 212 Tricyclododecane, 155 Triguanide, 280 Triiodides of elements, 219 Trimers of sulfimide, 219 Trioxatriphosphorinane, 197, 219 Trioxides, 196 order of precedence of, 106 Trioxopropanediyl, 168 Triphenylene, 148 Vita for coordination compds., 203 t in tritium-labeled compds., 220 Tachyon, 217 Tacticity of polymers, 222 Tantalate heptapotassium, 219 Tartaric acid addition compds. of, 192 Tautomeric compounds, 122 acetoacetanilide and pyrazolinone dyes, 216 amides and imidic acids, 165 anions, 180 cations, 184 cyclic amines and imines, 177 histidine, 205 hydrazides and hydrazonic acids, 165 tropolones, 122, 180 urea and carbamimidic acid, 183 Tellones, 174 order of precedence of, 106 Tellurals order of precedence of, 106 Tellurenic acids, 165 Telluric acid, 219 Tellurides, 200, 271 of elements, 219 order of precedence of, 106 Tellurinic acids, 165 Tellurinyl, 200 Tellurium compounds, 200 order of precedence of, 106 Telluro, 200 Tellurols, 175 order of precedence of, 106 Tellurophene, 146 Telluroxo, 174 Telomers, 222 Tercyclopropane, 157 Terpenes, 212 ACS proposed system of nomenclature for, 302 retrospective index searching for, 290 Terphenyl, 157 Terphenylcarboxylic acid, 163 Terphenyldiyl, 161 Terphenylyl, 162 Terpyrazolidine, 157 Tetra, 110 tetrahedro, 108 Tetrakis, 110 Tetraoxatetradecapentaene, 142 Tetraoxatetradecene, 142 Tetraoxatridecane, 142 Tetraoxatridecyl, 161 Tetraoxides, 196 Tetrapyrroles, 223 Tetrasiladecenylidene, 161 Tetrasilatetradecane, 142 Tetrasiloxane, 199 Tetrazadiene, 143 Tetrazane, 143 Tetrazene, 143 Theophylline, 122 Thia, 128 Thiaandrostane, 211 Thiadiazole abnormal valency in, 158 Thials, 173 order of precedence of, 106 Thiamine, 224 Thiaporphine, 223 Thiazolium vitamin B12 deriv., 224 Thiireno systems, 281 Thio, 200 Thio acids, 165, 200 of arsenic and phosphorus, 197 esters, 200 esters, S-oxides, 185 retrospective index searching for, 280 Thioamides, 171 S-oxides, 200 Thioboric acid, 219 Thiocyanic acid, 183, 219 anhydrosulfides, 183, 188 Thiodicarbonic acid, 129, 200 Thiodiphosphonic acid, 179 Triphosphonic acid, 179 Triphosphoric acid, 219 Triple bonds. See Unsaturated compounds Tris, 110 Trisilane order of precedence of, 106 Trisiloxane, 140, 144 Trisiloxanetriyl, 161 Tristannane, 143 Tristannathiane, 144 Tristannoxane, 199 Trisulfides, 200 order of precedence of, 106 Trisulfones, 200 order of precedence of, 106 Trisulfuric acid, 219 Trisulfuryl chloride, 219 Trithiaazatetradecenediyl, 161 Trithiatristannacyclohexane, 146 Trithiatriazine hexaoxide, 219 Tritium compds. labeled with, 220 Trivial names, 101 for monocyclic hetero systems, 146 Tropine, 204 Tropolones, 122, 180 Tyrosine peptides containing, 206 Ulosaric acids, 208 Ulosonic acids, 208 Ulosuronic acids, 208 -ulosyl, 208 Uninverted index names, 104, 108 brackets around index parent in multiplicative, 109 of esters, 104 of salts, 198 Unnilpentium, 219 Unsaturated compounds acyclic, 141 carbohydrates, 208 conjunctive names not formed from acyclic, 124 double vs. triple bonds in, 138 greater number of multiple bonds in parent of, 138 locants for, 114, 137 monocyclic hydrocarbons, 145 spiro systems, 156 steroids, 211 Von Baeyer systems, 155 Ununnilium fluoride, 219 Uracil, 122 Uranate, 219 Uranium complexes, 219 Uranium chloride oxide, 219 Uranyl, 219 Urea, 183 derivs., retrospective index searching for, 292 hydroxy, 193 no locants for monosubstituted, 117 polymers with formaldehyde, 222 tautomerism of, 183 Urethanes, 185 Ureylene carbonyldiimino as name for, 134 Uric acid, 122 Uridine, 210 Uridylic acid, 210 Uronamides, 208 -uronamidosyl, 208 Uronic acids, 208 -uronosyl, 208 Ursane, 212 Valency abnormal, in ring systems, 158, 161, 163 Valine, 205 peptides containing, 206 Vanadyl, 219 Vasopressin, 206 Veratraman, 211 Veratrum alkaloids, 211 Vinyl acetal polymers, 222 Vinyl alcohol polymers, 222 Vitamin A, 212, 224 Vita Naming and Indexing of Chemical Substances for Chemical Abstracts 2007 Xanthene, 149 amino derivs., 216 numbering of, 152 Xanthic acids, 185 Xanthine, 210 derivs., 122 Xanthophylls, 212 Xanthosine, 210 Xanthylic acid, 210 Xenonate, 219 Xenon compounds, 219 -yl, 161 -ylene, 161 Ylic acids nucleotides, 210 -ylidene, 161 added hydrogen for cyclic, 136 in multiplicative names, 125, 255 Ylides, 201, 276 -ylidyne, 161 -ylium, 184 -ylylidene, 161 -yne, 139, 141, 155 -ynyl, 161 Z, 203 report on, 301 Zincate dye derivs., 216 Zinc chloride double salts with dyes, 216 Zinc sulfide, 219 Zirconyl, 219 Zwitterionic compounds, 201, 293A 154 Vitamin B12, 224. See also Corrinoids Vitamins, 224 IUPAC-IUB tentative rules for, 297 retrospective index searching for, 293 Von Baeyer systems, 140, 155 cationic, 184 choice between, 138 oxygen-containing, 196 punctuation in, 108, 109, 155 radicals from, 161 Vowels elision of, 107, 146 Water, 219 in coordination compds., 219 hydrates, 113, 192, 265A, 311 labeled, 220 Willemite, 219 ...
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This note was uploaded on 02/17/2011 for the course CHEMISTRY 101 taught by Professor Csr during the Spring '11 term at University of Louisville.

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