Orbital Interaction Theory of Organic Chemistry

by Rauk, Arvi

• ISBN13: 9780471358336
• ISBN10: 0471358339
• Edition: 2nd
• Format: Hardcover
• Copyright: 2000-11-06
• Publisher: Wiley-Interscience

Summary

A practical introduction to orbital interaction theory and its applications in modern organic chemistry Orbital interaction theory is a conceptual construct that lies at the very heart of modern organic chemistry. Comprising a comprehensive set of principles for explaining chemical reactivity, orbital interaction theory originates in a rigorous theory of electronic structure that also provides the basis for the powerful computational models and techniques with which chemists seek to describe and exploit the structures and thermodynamic and kinetic stabilities of molecules. Orbital Interaction Theory of Organic Chemistry, Second Edition introduces students to the fascinating world of organic chemistry at the mechanistic level with a thoroughly self-contained, well-integrated exposition of orbital interaction theory and its applications in modern organic chemistry. Professor Rauk reviews the concepts of symmetry and orbital theory, and explains reactivity in common functional groups and reactiveintermediates in terms of orbital interaction theory. Aided by numerous examples and worked problems, he guides readers through basic chemistry concepts, such as acid and base strength, nucleophilicity, electrophilicity, and thermal stability (in terms of orbital interactions), and describes various computational models for describing those interactions. Updated and expanded, this latest edition of Orbital Interaction Theory of Organic Chemistry includes a completely new

Author Biography

ARVI RAUK, PhD, is Professor Emeritus in the Department of Chemistry at the University of Calgary in Calgary, Canada.

Table of Contents

Preface	xiii
Symmetry and Stereochemistry	1	(19)
Purpose	1	(1)
Definition of a Group	2	(1)
Molecular Point Groups	2	(1)
Schoenflies Notation	2	(1)
Interrelations of Symmetry Elements	3	(1)
Type Classification	3	(3)
Isomerism and Measurements	6	(2)
Stereoisomerism of Molecules	8	(1)
Stereotopic Relationships of Groups in Molecules	9	(1)
Asymmetric Synthesis and Stereochemistry	10	(2)
NMR and Stereochemistry	12	(2)
Symmetry and Structural Parameters	14	(1)
Note on Hybridization	15	(1)
Symmetry and Orbitals	16	(3)
Atomic Orbitals	16	(1)
Molecular and Group Orbitals	17	(2)
In what Combination?	19	(1)
Molecular Orbital Theory	20	(14)
Introduction	20	(1)
Electronic Schrodinger Equations (A.1)	21	(2)
Fock Equations (A.42)	23	(1)
The Basis Set (STO-3G, 6-31G*, and All That)	24	(1)
Orbital Energies and Orbitals	25	(2)
Representation of MOs	27	(2)
Total Energies and the Hartree-Fock Limit	29	(1)
Successes and Failures of Hartree-Fock Theory	29	(1)
Beyond Hartree-Fock	30	(1)
Density Functional Theory	31	(1)
Geometry Optimization	31	(1)
Normal Coordinates and Harmonic Frequency Analysis	32	(1)
Zero Point Vibrational Energies	33	(1)
Orbital Interaction Theory	34	(38)
Relationship to Hartree-Fock Equations	34	(1)
Huckel Approximation	34	(1)
Orbital Energies and Total Electronic Energy	34	(1)
Case Study of a Two-Orbital Interaction	35	(9)
εA = εB, SεAB = 0	38	(1)
εA = εB, SεAB > 0, SAB « 1	39	(1)
εA > εB, SAB = 0	40	(2)
εA > εB, SAB > 0	42	(2)
Effect of Overlap	44	(1)
Energetic Effect of Overlap	44	(1)
Orbital Effect of Overlap	44	(1)
First Look at Bonding	45	(1)
Relationship to Perturbation Theory	45	(1)
Generalizations for Intermolecular Interactions	46	(1)
Energy and Charge Distribution Changes from Orbital Interaction	47	(5)
Four-Electron, Two-Orbital Interaction	47	(1)
Three-Electron, Two-Orbital Interaction	48	(1)
Two-Electron, Two-Orbital Interaction	49	(2)
One-Electron, Two-Orbital Interaction	51	(1)
Zero-Electron, Two-Orbital Interaction	51	(1)
Interactions between Molecules: Many Electrons, Many Orbitals	52	(3)
General Principles Governing the Magnitude of hAB and SAB	52	(1)
Interactions of MOs	52	(3)
Electrostatic Effects	55	(1)
Group Orbitals	56	(5)
Zero-Coordinated Atoms	56	(1)
Monocoordinated Atoms	57	(1)
Dicoordinated Atoms	58	(1)
Tricoordinated Atoms	59	(1)
Tetracoordinated Atoms	59	(2)
Assumptions for Applications of Qualitative MO Theory	61	(1)
Example: Carbonyl Group	62	(1)
Construction of Interaction Diagram	62	(3)
Interpretation of Interaction Diagram	65	(1)
Chemical Reactivity	66	(3)
Why Does It Work and When Might it Not?	69	(3)
Sigma Bonds and Orbital Interaction Theory	72	(14)
C-X σ Bonds: X = C, N, O, F and X = F, Cl, Br, I	72	(2)
σ Bonds: Homolytic versus Heterolytic Cleavage	74	(3)
Heterolytic Cleavage of σ Bonds Involving C or H	74	(1)
Homolytic Cleavage of σ Bonds Involving C or H	75	(1)
Homonuclear σ Bonds C-C, N-N, O-O, F-F, Cl-Cl, Br-Br, and I-I	76	(1)
Interactions of σ Bonds	77	(4)
σ Bonds as Electron Donors or Acceptors	81	(1)
σ Bonds as Electron Acceptors	81	(2)
As a σ Acceptor	81	(1)
As a π Acceptor	82	(1)
σ Bonds as Electron Donors	83	(1)
As a σ Donor	83	(1)
As a π Donor	84	(1)
Bonding in Cyclopropane	84	(2)
Simple Huckel Molecular Orbital Theory	86	(12)
Simple Huckel Assumptions	86	(5)
Charge and Bond Order in SHMO Theory: (SAB = 0, One Orbital per Atom)	91	(1)
Electron Population and Net Charge of Center A	91	(1)
Bond Order between Centers A and B	92	(1)
Factors Governing Energies of MOs: SHMO Theory	92	(1)
Reference Energy and Energy Scale	92	(1)
Heteroatoms in SHMO Theory	93	(3)
Effect of Coordination Number on α and β	93	(3)
Hybridization at C in Terms of α and β	96	(1)
Gross Classification of Molecules on the Basis of MO Energies	96	(2)
Reactions and Properties of π Bonds	98	(7)
Reactions of Olefins (Alkenes)	98	(1)
Effect of X: Substituents	99	(2)
Effect of Z Substituents	101	(1)
Effect of ``C'' Substituents	101	(1)
Effect of Distortion of Molecular Skeleton	102	(1)
Alkynes	103	(1)
π Bonds to and between Higher Row Elements	103	(1)
π Bonds to Silicon, Phosphorus, and Sulfur	103	(2)
Reactive Intermediates	105	(16)
Reactive Intermediates [CH3]+, [CH3]-, [CH3., and [:CH2]	105	(11)
Carbocations	105	(1)
Intermolecular Reactions of Carbocations	106	(1)
Intramolecular Reactions of Carbocations	107	(1)
Silyl Cations	108	(1)
Carbanions	108	(2)
Carbon Free Radicals	110	(4)
Carbenes	114	(2)
Nitrenes and Nitrenium Ions	116	(5)
Nitrenes	116	(2)
Nitrenium Ions	118	(3)
Carbonyl Compounds	121	(8)
Reactions of Carbonyl Compounds	121	(6)
Electrophilic Attack on a Carbonyl Group	121	(1)
Basicity and Nucleophilicity of the Oxygen Atom	122	(2)
Nucleophilic Attack on a Carbonyl Group	124	(2)
Amide Group	126	(1)
Thermodynamic Stability of Substituted Carbonyl Groups	127	(2)
Nucleophilic Substitution Reactions	129	(8)
Nucleophilic Substitution at Saturated Carbon	129	(8)
Unimolecular Nucleophilic Substitution SN1	129	(1)
Bimolecular Nucleophilic Substitution SN2	130	(4)
Another Description of the SN2 Reaction: VBCM Model	134	(3)
Bonds to Hydrogen	137	(13)
Hydrogen Bonds and Proton Abstraction Reactions	137	(8)
Hydrogen Bonds	137	(2)
Symmetrical and Bifurcated Hydrogen Bonds	139	(2)
Proton Abstraction Reactions	141	(2)
E2 Elimination Reaction	143	(1)
ElcB Mechanism Reaction	144	(1)
E1 Elimination Reaction	144	(1)
Reaction with Electrophiles: Hydride Abstraction and Hydride Bridging	145	(2)
Activation by π Donors (X: and ``C'' Substituents)	145	(1)
Hydride Abstraction	145	(2)
Hydride Bridges	147	(1)
Reaction with Free Radicals: Hydrogen Atom Abstraction and One- or Three-Electron Bonding	147	(1)
Hydrogen-Bridged Radicals	147	(1)
Hydrogen Atom Transfer	148	(2)
Aromatic Compounds	150	(11)
Reactions of Aromatic Compounds	150	(2)
Cyclic π Systems by Simple Huckel MO Theory	150	(1)
Aromaticity in σ-Bonded Arrays?	151	(1)
Reactions of Substituted Benzenes	152	(1)
Electrophilic Substitutions	152	(5)
Effect of Substituents on Substrate Reactivity	153	(1)
Electrophilic Attack on X: -Substituted Benzenes	153	(1)
Electrophilic Attack on Z-Substituted Benzenes	154	(1)
Electrophilic Attack on ``C''-Substituted Benzenes	155	(1)
Electrophilic Attack on N Aromatics: Pyrrole and Pyridine	155	(2)
Nucleophilic Substitutions	157	(2)
Effect of Substituents on Substrate Reactivity	158	(1)
Nucleophilic Attack on Z-Substituted Benzenes	158	(1)
Nucleophilic Attack on N Aromatics: Pyrrole and Pyridine	158	(1)
Nucleophilic Substitution by Proton Abstraction	159	(2)
Pericyclic Reactions	161	(14)
General Considerations	161	(1)
Cycloadditions and Cycloreversions	162	(3)
Stereochemical Considerations	162	(3)
Electrocyclic Reactions	165	(1)
Stereochemical Considerations	165	(1)
Cheletropic Reactions	165	(1)
Stereochemical Considerations	165	(1)
Sigmatropic Rearrangements	166	(1)
Stereochemical Considerations	166	(1)
Component Analysis (Allowed or Forbidden?)	167	(4)
Rule for Component Analysis	168	(1)
Diels-Alder Reaction	169	(1)
Cope Rearrangement	170	(1)
1, 3-Dipolar Cycloaddition Reactions	171	(4)
Organometallic Compounds	175	(21)
Transition Metals	175	(1)
Ligands in Transition Metal Complexes	176	(1)
Orbitals in Transition Metal Bonding	176	(2)
Orbital Energies	178	(1)
Valence Orbitals of Reactive Metal Complexes	179	(3)
Six Valence Orbitals of Tricoordinated Metal	182	(1)
Five Valence Orbitals of Tetracoordinated Metal	182	(3)
Four Valence Orbitals of Pentacoordinated Structure	185	(1)
Transition Metals and C-H or H-H Sigma Bonds	186	(1)
More About C Ligands in Transition Metal Complexes	186	(1)
Chelating Ligands	187	(1)
Organic π-Bonded Molecules as Ligands	187	(1)
Transition Metal Bonding to Alkenes: Zeise's Salt	187	(4)
Agostic Interaction	191	(1)
Ziegler-Natta Polymerization	192	(2)
Oxidative Addition to H-H and C-H Bonds	194	(2)
Orbital and State Correlation Diagrams	196	(13)
General Principles	196	(1)
Woodward-Hoffman Orbital Correlation Diagrams	197	(6)
Cycloaddition Reactions	197	(1)
Electrocyclic Reactions	198	(3)
Cheletropic Reactions	201	(1)
Photochemistry from Orbital Correlation Diagrams	201	(2)
Limitations of Orbital Correlation Diagrams	203	(1)
State Correlation Diagrams	203	(6)
Electronic States from MOs	205	(1)
Rules for Correlation of Electronic States	206	(1)
Example: Carbene Addition to an Olefin	206	(3)
Photochemistry	209	(9)
Photoexcitation	209	(1)
Jablonski Diagram	210	(1)
Fate of Excited Molecule in Solution	211	(1)
Dauben-Salem--Turro Analysis	212	(1)
Norrish Type II Reaction of Carbonyl Compounds	213	(2)
Norrish Type I Cleavage Reaction of Carbonyl Compounds	215	(3)
APPENDIX A: DERIVATION OF HARTREE-FOCK THEORY	218	(29)
Electronic Hamiltonian Operator	218	(2)
Electronic Schrodinger Equation	220	(1)
Expectation Values	221	(1)
Many-Electron Wave Function	221	(1)
Electronic Hartree-Fock Energy	222	(4)
Variation of EHF	226	(3)
LCAO Solution of Fock Equations	229	(2)
Integrals	231	(1)
The Basis Set (STO-3G, 6-31G*, and All That)	232	(1)
Interpretation of Solutions of HF Equations	233	(1)
Orbital Energies and Total Electronic Energy	233	(1)
Restricted Hartree-Fock Theory	234	(2)
Mulliken Population Analysis	236	(1)
Dipole Moments	236	(1)
Total Energies	237	(1)
Configuration Energies	237	(2)
Post-Hartree-Fock Methods	239	(1)
Configuration Interaction Theory	239	(2)
Excited States from CI Calculations	241	(1)
Many-Body Perturbation Theory	241	(1)
Rayleigh-Schrodinger Perturbation Theory	241	(3)
Møller-Plesset Perturbation Theory	244	(1)
Density Functional Theory	245	(2)
APPENDIX B: EXERCISES	247	(66)
Chapter 1	247	(2)
Chapter 2 and Appendix A	249	(3)
Chapter 3	252	(10)
Chapter 4	262	(2)
Chapter 5	264	(8)
Chapter 6	272	(1)
Chapter 7	273	(5)
Chapter 8	278	(3)
Chapter 9	281	(1)
Chapter 10	281	(3)
Chapter 11	284	(4)
Chapter 12	288	(4)
Chapter 13	292	(4)
Chapter 14	296	(2)
Chapter 15	298	(3)
Miscellaneous	301	(12)
References and Notes	313	(12)
Index	325