Register now to access 7 million high quality study materials (What's Course Hero?) Course Hero is the premier provider of high quality online educational resources. With millions of study documents, online tutors, digital flashcards and free courseware, Course Hero is helping students learn more efficiently and effectively. Whether you're interested in exploring new subjects or mastering key topics for your next exam, Course Hero has the tools you need to achieve your goals.

3 Pages

Transition Metals

Course: CH 1a, Fall 2008
School: Caltech
Rating:

Word Count: 2510

Document Preview

Unformatted Document Excerpt

Coursehero >> California >> Caltech >> CH 1a

Course Hero has millions of student submitted documents similar to the one
below including study guides, practice problems, reference materials, practice exams, textbook help and tutor support.

Course Hero has millions of student submitted documents similar to the one below including study guides, practice problems, reference materials, practice exams, textbook help and tutor support.

and Chemistry Spectroscopy of the Transition Metals Bonding of d-orbitals Color/Spectroscopy Magnetic Properties Electron Transfer Chemistry Organization of Periodic Chart 1s 2s 3s 4s 5s 6s 7s 1s 3d 4d 5d 6d 4f 5f 2p 3p 4p 5p 6p r22 1s 3d Shielding 3p 3s Penetration: 3s > 3p > 3d A 3s electron penetrates the 1s orbital better than a 3p electron r Transition Metals Are Found in Several Oxidation States Charge to mass ratio of ions: current which passes through circuit divided by mass gained on electrode. e- Ammeter Faraday (1830): discovered this phenomenon and determined the charge to mass ratio of ions M+ M+ M+ M+ Exceptions to Filling Order H Li Na K Rb Cs Fr Be Mg Ca Sr Ba Ra 2s 3s 4s Sc Y La Ac Ce Th Pr Pa Ti Zr Hf V Nb Ta Cr W 3d Mn Fe Ru Os Re Co Rh Ir Ni Pd Pt Mo Tc 2p 3p 4p Cu Ag Au Zn Cd Hg He B Al Ga In Tl C Si Ge Sn Pb N P As Sb Bi O S Se Te Po F Cl Br I At Ne Ar Kr Xe Rn Nd U Pm Sm Eu Np Pu Gd Tb Dy Cf Ho Es Er Tm Yb Lu Lr Am Cm Bk Fm Md No 23. V (4s)2(3d)3 24. Cr (4s)1(3d)5 25. Mn (4s)2(3d)5 Exceptions occur because electrons dont like to pair up in orbitals; so the highlighted 4s atoms have lower energy. 40. Zr (5s)2(4d)2 41. Nb (5s)1(4d)4 42. Mo (5s)1(4d)5 3d All Metal Ions Have dn Configurations H Li Na K Rb Cs Fr Be Mg Ca Sr Ba Ra 2s 3s 4s Sc Y La Ac Ce Th Pr Pa Ti Zr Hf V Nb Ta Cr W 3d Mn Fe Ru Os Re Co Rh Ir Ni Pd Pt Mo Tc 2p 3p 4p Cu Ag Au Zn Cd Hg He B Al Ga In Tl C Si Ge Sn Pb N P As Sb Bi O S Se Te Po F Cl Br I At Ne Ar Kr Xe Rn Nd U Pm Sm Eu Np Pu Gd Tb Dy Cf Ho Es Er Tm Yb Lu Lr Am Cm Bk Fm Md No 23. V (4s)2(3d)3 24. Cr (4s)1(3d)5 25. Mn (4s)2(3d)5 Cr -3e4s Cr(III) 3d 23. V(II) 24. Cr(III) 25. Mn(IV) (3d)3 (3d)3 (3d)2 All Metal Ions Have dn Configurations H Li Na K Rb Cs Fr Be Mg Ca Sr Ba Ra 2s 3s 4s Sc Y La Ac Ce Th Pr Pa Ti Zr Hf V Nb Ta Cr W 3d Mn Fe Ru Os Re Co Rh Ir Ni Pd Pt Mo Tc 2p 3p 4p Cu Ag Au Zn Cd Hg He B Al Ga In Tl C Si Ge Sn Pb N P As Sb Bi O S Se Te Po F Cl Br I At Ne Ar Kr Xe Rn Nd U Pm Sm Eu Np Pu Gd Tb Dy Cf Ho Es Er Tm Yb Lu Lr Am Cm Bk Fm Md No 40. Zr (5s)2(4d)2 41. Nb (5s)1(4d)4 42. Mo (5s)1(4d)5 Nb -3eNb(III) 5s 4d 40. Zr(II) 41. Nb(III) 42. Mo(III) (4d)2 (4d)2 (4d)2 Nobel Prize in Chemistry, 1913 Alfred Werner "in recognition of his work on the linkage of atoms in molecules by which he has thrown new light on earlier investigations and opened up new fields of research especially in inorganic chemistry Zurich University Chemistry of Coordination Complexes [Ni(H2O)6 ] 2+ + 6 NH3 Green Fe(H2O)63+ + 6 K(CN) Fe(H2O)62+ + 6 K(CN) Cu(H2O)42+ + 4 KCl [Ni(NH3)6 ] 2+ + 6 H2O Blue-violet K4[Fe(CN)6]4- + 6 H2O Ni(II) d8 Fe(II) d6 K4[Fe(CN)6]4-+ 6 H2O + 2 K+ Fe(III) d5 K2[CuCl4]2- + 4 H2O + 2 K+ Cu(II) d9 Stereochemistry of Coordination Complexes Pt (NH3)2Cl2 Cl Pt Cl NH3 NH3 Pt Cl NH3 Cl NH3 Pale Yellow No dipole Orange-Yellow (dipole moment) (cis-platin) Nobel Prize in Physics, 1966 Hans Bethe, Cornell Discovery of the C/N cycle that supplies energy to brilliant stars, 1935-1938 Atomic physics and collision theory Nuclear forces acting on the nucleon Lamb shift in the H-spectrum; modern quantum electrodynamics mesons and their production by electromagnetic radiation Crystal Field theory: 1929 Crystal Field Splitting Octahedral Complexes z2 x2-y2 Non-spherical symmetry O o Extra electron density d xz yz xy C C O O C O C Cr C C O O Crystal Field Splitting Octahedral Complexes z2 x2-y2 o xz yz xy z2 x2-y2 d z2 x2-y2 xz o xz yz xy yz xy Crystal Field Splitting Tetrahedral Complexes xz yz xy t z2 x2-y2 d t= -4/9 o Crystal Field Splitting Octahedral Complexes xz yz xy t z2 x2-y2 d z2 x2-y2 xz yz xy xz z2 x2-y2 yz xy t Crystal Field Splitting Tetrahedral Complexes xz yz xy t z2 x2-y2 d t= -4/9 o Spectrochemical Series I- < Br - < Cl - < F Donors z2 x2-y2 o xz yz xy xz yz xy z2 x2-y2 o Spectrochemical Series z2 x2-y2 o xz yz xy z2 x2-y2 o xz yz xy o: Mn2+ < Ni2+ < Rh3+ < Co2+ < Fe2+ < Fe3+ < Cr3+ < Co3+ < Ir3+ < Pt4+ Spectrochemical Series I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors Acceptors z2 x2-y2 o xz yz xy z2 x2-y2 o xz yz xy Spectrochemical Series * z2 x2-y2 o xz yz xy xz yz xy b z2 x2-y2 o Crystal Field Splitting Octahedral Complexes z2 x2-y2 o d No net overlap z2 xz yz xy x2-y2 z2 x2-y2 xz o xz yz xy yz xy overlap Transition Metal Chemistry Multiple Oxidation States Coordination Chemistry/Stereochemistry Crystal Field Splitting: Optical and Magnetic Properties Ligand Field Splitting: Spectrochemical Series Distortion to Tetragonal, Square Planar Ligand Field Stabilization Energy Hard and Soft Acids and Bases Chelate Effect Stereochemical Control of Binding Affinity Water Exchange Electron Exchange Spectrochemical Series I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors Acceptors z2 x2-y2 o xz yz xy z2 x2-y2 o xz yz xy Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d1 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d2 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d3 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d4 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d5 z2 x2-y2 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d6 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d7 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d8 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors x2-y2 Magnetic z2 Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d9 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Magnetic Properties of Octahedral Complexes I- < Br - < Cl - < F - < OH - < H2O < NH3 < CN - <CO Donors d10 z2 x2-y2 o xz yz xy xz yz xy High Spin Low Spin o Acceptors z2 x2-y2 Crystal Field Splitting Tetrahedral Complexes xz yz xy t z2 x2-y2 d t= -4/9 o (Almost) No low spin tetrahedral complexes Transition Metal Chemistry Multiple Oxidation States Coordination Chemistry/Stereochemistry Crystal Field Splitting: Optical and Magnetic Properties Ligand Field Splitting: Spectrochemical Series Distortion to Tetragonal, Square Planar Ligand Field Stabilization Energy Hard and Soft Acids and Bases Chelate Effect Stereochemical Control of Binding Affinity Water Exchange Electron Exchange Jahn-Teller Tetragonal Distortion X X Cu X X X X X X Cu-X Cu-X Cl 2.30 2.95 Br 2.40 3.18 F 1.93 2.27 Bonds lengthen on z-axis d9 z2 o xz yz xy X Cu X X X X z2 x2-y2 x2-y2 o xz yz xy Square Planar Complexes X X Rh(I) X X z2 x2-y2 X Bonds lengthen on z-axis d8 x2-y2 z2 o xz yz xy xz yz xy o X X X X Rh(I) X X X Square Planar Complexes X X Rh(I) X X z2 x2-y2 d8 X Bonds lengthen on z-axis x2-y2 X X X Rh(I) X X o xz yz xy xy z2 xz yz Transition Metal Chemistry Multiple Oxidation States Coordination Chemistry/Stereochemistry Crystal Field Splitting: Optical and Magnetic Properties Ligand Field Splitting: Spectrochemical Series Distortion to Tetragonal, Square Planar Ligand Field Stabilization Energy Hard and Soft Acids and Bases Chelate Effect Stereochemical Control of Binding Affinity Water Exchange Electron Exchange Ligand Field Stabilization Energy High Spin Octahedral Complexes z2 x2-y2 Non-spherical symmetry xz yz xy dn d1, d6 d2, d7 d3, d8 d4, d9 d0, d5, d10 3/5 o o 2/5 o Extra electron density d H2O H2O H2O M H2O H2O H2O o 2/5 4/5 6/5 3/5 0 Ligand Field Stabilization Energy M2+(g) + H2O 3000 [M(H2O)6]2+ Hydration Energy (kJ/mol) 2500 Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Hard and Soft Acids and Bases M +L ML Complexes (b) Weakest Complexes (a) Ligands Strongest R3N R2O FR3P R2S ClR3As R2Se BrWeakest R3Sb R2Te I- Strongest Type a (hard): Li+, Na+, K+, Cs+, Mg2+, Ca2+, Ti3+, Fe3+, Co3+, Al3+ Type b (soft): Hg22+, Hg2+, Pt2+, Pt4+, Ag+, Cu+, low valent Ms Binding Constants for Multiple Ligands K Cd2+ [Cd(NH3)]2+ [Cd(NH3)2]2+ [Cd(NH3)3]2+ Cd2+ + NH3 + NH3 + NH3 + NH3 + 4 NH3 [Cd(NH3)]2+ [Cd(NH3)2]2+ [Cd(NH3)3]2+ [Cd(NH3)4]2+ [Cd(NH3)4]2+ 102.05 102.10 101.44 100.93 107.12 Decrease mostly statistical: as ligand count increases more changes to lose L as opposed to gaining L Chelate Effect Ni2+ + 6 NH3 K = 108.6 NH3 NH3 NH3 Ni 2+ NH3 NH3 NH3 NH2 NH2 Ni2+ + 3 H2NCH2CH2NH3 K = 1018.3 NH2 Ni 2+ NH2 NH2 H2 N Chelate Effect Useful chelating ligands: en, sepulchrate, edta, O CH2-C O - O C-CH2 : NCH2CH2N : -O OC-CH2 CH2-C O O edta M2+ O N M 2+ N O M(edta)2O NH NH M(sep) 2+ O M2+ NH M 2+ NH O NH NH NH NH NH NH NH NH Ionic Radii and Charge Densities for the Alkali Metal Cations Ion Li+ Na+ K+ Rb+ Cs+ Ionic radius/ 0.66 0.95 1.33 1.48 1.69 Charge Density/C -3 12.1x10-20 4.46x10-20 1.62x10-20 1.18x10-20 0.79x10-20 So how do we use hard ligands to bind Na+ or K+ vs Li+? Chelate Effect Useful chelates: crown ethers (host/guest chemistry) M+ 18-crown 6 Fits Cs+ nicely (used to separate Cs in radioactive waste) Crown Ethers Fits Na+ and K+ nicely 15-crown 5 (C10H20O5) Crown Ethers 12-crown 4 + Li+ 1987 Nobel Prize in Chemistry Donald Cram Charles J. Pedersen Jean-Marie Lehn "for their development and use of molecules with structure-specific interactions of high selectivity" Crown Ethers Useful chelates: crown ethers (host/guest chemistry) Also used to bring along pertechnetate anion into non-aqueous solvents Biological Host-Guest Complexes Transports K+ through lipid membranes K+-Valinomycin Complex Top View Side View Biological Ionophores Li+ Valinomycin Monactin Enniatin B Nigericin Monensin <0.7 <0.3 1.28 3.6 Na+ 0.67 2.60 2.42 4.7 6.5 K+ 4.90 4.38 2.92 5.6 5.0 Rb+ 5.26 4.38 2.74 5.0 4.3 Cs+ 4.42 3.30 2.34 3.6 Water Exchange Rates M(H2O)n+ + H2O k (s-1) Class I: 108 Na+, K+, Rb+, Cs+, Ca2+, Sr2+, Ba2+ Cr2+, Cu2+ Mg2+, Be2+, Mn2+, Fe2+, Co2+, Ni2+ Be2+, Al3+, Ga3+, V2+ Cr3+, Co3+, Rh3+, Ir3+, Pt2+ M(H2O)n+ + H2O Class II: 104-108 Class III: 1-104 Class IV: 10-6-10-3 k decreases as ion size decreases k decreases as charge increases d6 = Co3+, Rh3+, Ir3+, d3 = Cr3+ Nobel Prize in Chemistry, 1967 Manfred Eigen "for their studies of extremely fast chemical reactions, effected by disturbing the equlibrium by means of very short pulses of energy" Electron Exchange Simplest chemical reaction, yet enormous rate differences [Co (NH3)6]3+ + ek = 10-6 M-1 s-1 [Co (NH3)6]2+ [Ru(NH3)6]3+ + e- [Ru(NH3)6]2+ k = 104 M-1 s-1 Nobel Prizes in Chemistry (and nice guys finish first) 1983 1992 Henry Taube "for his work on the mechanisms of electron transfer reactions, especially in metal complexes" Rudy Marcus "for his contributions to the theory of electron transfer reactions in chemical systems" Nuclei do all the work, then the electrons move Electron Exchange z2 x2-y2 [Co (NH3)6]3+ + ez2 x2-y2 [Co (NH3)6]2+ xz yz xy z2 x2-y2 xz yz xy z2 x2-y2 [Ru(NH3)6]3+ xz yz xy + e- [Ru(NH3)6]2+ xz yz xy Electron Exchange NH3 Ru3+ NH3 NH3 z2 x2-y2 [Ru(NH3)6]3+ xz yz xy + eNH3 NH3 NH3 Ru2+ NH3 NH3 NH3 NH3 NH3 NH3 z2 x2-y2 [Ru(NH3)6]2+ xz yz xy Electron Exchange NH3 NH3 NH3 Co3+ NH3 NH3 NH3 NH3 NH3 Co2+ NH3 NH3 z2 x2-y2 + eNH3 NH3 z2 x2-y2 [Co (NH3)6]3+ [Co (NH3)6]2+ xz yz xy xz yz xy Electron Exchange NH3 NH3 NH3 Co NH3 + NH3 NH3 Co NH3 NH3 2+ 3+ NH3 NH3 NH3 NH3 NH3 Co3+ NH3 NH3 NH3 + NH3 NH3 NH3 Co2+ NH3 NH3 NH3 NH3 NH3 Electron Exchange z2 x2-y2 z2 x2-y2 [Co (NH3)6]*2+ xz yz xy z2 x2-y2 + e- [Co (NH3)6]*3+ xz yz xy z2 x2-y2 [Co (NH3)6]3+ [Co (NH3)6]2+ xz yz xy xz yz xy Electron Exchange z2 x2-y2 z2 x2-y2 [Co (NH3)6]*2+ xz yz xy z2 x2-y2 + e- [Co (NH3)6]*3+ xz yz xy z2 x2-y2 [Co (NH3)6]3+ [Co (NH3)6]2+ xz yz xy xz yz xy Transition Metal Chemistry Multiple Oxidation States Coordination Chemistry/Stereochemistry Crystal Field Splitting: Optical and Magnetic Properties Ligand Field Splitting: Spectrochemical Series Distortion to Tetragonal, Square Planar Ligand Field Stabilization Energy Hard and Soft Acids and Bases Chelate Effect Stereochemical Control of Binding Affinity Water Exchange Electron Exchange

Find millions of documents on Course Hero - Study Guides, Lecture Notes, Reference Materials, Practice Exams and more. Course Hero has millions of course specific materials providing students with the best way to expand their education.

Below is a small sample set of documents:

VSEPR

Caltech - CH - 1a

VSEPRReading: Gray: (4-5) OGN: (3.6) and (3.7)Bonding in Complex Molecules TaxolValence Shell Electron Pair Repulsion Theory (VSEPR) Predicts the shapes of molecules Works very well for octets and for expanded octets (2nd and 3rd row elements

LS1b08 Practice_Exam1

Harvard - LIFE SCIEN - 1b

ID#_Name_TF Name _ > Please put your name at the top of each page <Life Sciences 1b 2008 Practice Exam 1Keep exam closed until told to begin You will have exactly 1 hour and 20 minutes for the exam. If you finish early, quietly bring your ex

LS1b08 Practice_Exam1_KEY

Harvard - LIFE SCIEN - 1b

ID#_Name_Answer Key_TF Name _ > Please put your name at the top of each page <Life Sciences 1b 2008 Practice Exam 1Keep exam closed until told to begin You will have exactly 1 hour and 20 minutes for the exam. If you finish early, quietly br

LS1b08_Pre-Exam_Quiz_KEY

Harvard - LIFE SCIEN - 1b

Pre-Exam Quiz (10 points)Name TF Grade/10Fill in the correct answer in the space provided: Grading notes: No partial credit. Only the answer in the space provided is graded. Equivalent unreduced or partially reduced equations earn full credit.

LS1b08 Exam1_KEY

Harvard - LIFE SCIEN - 1b

ID#_Name_Answer Key_TF Name _ > Please put your name at the top of each page <Life Sciences 1b 2008 Exam 1Keep exam closed until told to begin You will have exactly 1 hour and 20 minutes for the exam. If you finish early, quietly bring your

CambodiansPlunderGravesofMassMurders

University of Louisville - MUH - 204

WILLIAMS01 - GREAT WESTERN TRANSFORMATION

University of Louisville - HUM - 304

Why are the Highlands High-Part 2