Unformatted text preview: Complex Ion Formulas and Nomenclature (Coordination Chemistry)
By: Robert Klaasen The Basics Coordination Compounds usually involve transition metal ions (colored and often paramagnetic) A neutral Coordination Compound consists of a complex ion (a transition metal with attached ligands) and counter ions (anions or cations needed to produce a neutral compound). Important Definitions Ligands are Lewis bases with lone pairs of electrons. These electrons can be donated to the empty d orbitals of a transition metal ion, which can act as a Lewis Acid. This is a coordinate covalent bond. Example 1 [Co(NH3)6]Cl3 The The complex ion is [Co(NH3)6]3+ Co3+ and six attached NH3 ligands counter ion is Cl- Naming Complex Ions (Cations)
Complex Cations Named by giving the # & name of groups attached to central metallic atom, followed by the name of the central atom, with its oxidation # like normal cations i.e. Iron (III) Cr(H2O)63+ Six water molecules (hexaaquo) Bonded to a Chromium(III) ion Gives you Hexaaquochromium(II I) (If you can pronounce it) Naming Complex Ions (Anions) Complex Anions Named by giving the # & name of the central metallic atom, followed by the name of the central atom, with an ate ending & oxidation # like the complex cation PtCl62 Six Chlorine ions (hexachloro) Bonded to a Platinum (IV) ion (Platinate) Gives you Hexachloroplatinate(I V) IUPAC Rules for Naming Coordination Compounds
1. 2. 3. The cation is always named before the anion, and with a space between them. The ligands are named before the metallic ion. Ligands have special endings. (See Chart on Next Slide) Rules Cont.
1. 2. 3. Ligands named first in alphabetical order, followed by the metal name. Use prefixes (bi, tri, tetra etc, no mono), however they don't affect the alphabetical order. Indicate oxidation # by roman numerals. For complex ions w/negative charge, suffix ate is added to the metal name. (Only for charged) Use the latin names cuprate (copper), aurate (gold), ferrate (iron), plumbate (lead), argentate (silver) and stannate (stannate). And More Rules...
1. In the case of complex isomerism, the names cis or trans may precede the formula of the complex-ion name to indicate the spatial arrangement of the ligands. Cis means adjacent, trans means opposite. Examples [Ni(CO)4] tetracarbonylnickel(0) a.k.a. liquid death [Zn(NH3)4]Cl2 tetraamminezinc chloride K2[CoCl4] potassium tetrachlorocobaltate(II) And Now a Tricky one [Pt(NH3)4][PtCl6] tetraammineplatinum(II) hexachloroplatinate(IV) Questions Anyone?
(This is your second-to-last chance) ...Then Quiz Time
Name the following Complex Ions 1. Na[Al(OH)4]
2. 3. [Cu(NH3)4](NO3)2 [Ag(NH3)2]Cl Answers to Part I
1. 2. 3. sodium tetrahydroxoaluminate tetraamminecopper(II) nitrate diamminesilver chloride Quiz Part II
Write the formula for the given name potassium hexacyanoferrate(III) sodium hexafluoroaluminate diamminesilver ion Answers to Part II
1. 2. 3. K3[Fe(CN)6] Na3[Al(F)6] [Ag(NH3)2] Final Questions, Concerns, Comments or Quibbles? ...
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- Spring '07
- Chemistry, Ion, Lone pair, Complex Ions, Coordination complex