Introduction to Magnetic Resonance

Title Page
Acknowledgments
Preface
Contents
Short Bibliography
Table of Atomic and Magnetic Constants
1. Principles of Magnetic Resonance
	1.1 Introduction
	1.2 The NMR Experiment
	1.3 The ESR Experiment
	1.4 Thermal Equilibrium and Spin Relaxation
	1.5 The Resonance Line Shape
	1.6 Magnetic Interactions
	Problems
	Suggestions for Further Reading
2. Magnetic Resonance Spectra of the Hydrogen and Helium Atoms
	2.1 Introduction
	2.2 The Magnetic Hamiltonian
	2.3 Perturbation Theory
	2.4 The Basic Spin Functions and Zero-Order Energies
	2.5 The First-Order Hyperfine Energies
	2.6 The Second-Order Hyperfine Interaction
	2.7 The First Order ESR Spectrum
	2.8 The Second-Order ESR Spectrum - Forbidden Transitions
	2.9 The Zero-Field Levels of Hydrogen
	2.10 The NMR Spectrum of the Helium Atom
	2.11 Chemical Shielding
	2.12 Corrections to the g Factor
	2.13 Anisotropic Effects
	Problems
	Suggestions for Further Reading
3. Nuclear Resonance in Solids
	3.1 Introduction
	3.2 The Dipolar Coupling Tensor
	3.3 The NMR Spectrum of Two Coupled Protons
	3.4 The Second Moment of an NMR Absorption Line
	3.5 Structural Studies by the Method of Moments
	3.6 Nuclear Quadrupole Resonance
	Problems
	Suggestions for Further Reading
4. The Analysis of NMR Spectra in Liquids
	4.1 Introduction
	4.2 The Chemical Shift
	4.3 The Spin-Spin Coupling
	4.4 The Analysis of Complex Spectra
		4.4.1 Classification of Spectra
		4.4.2 The Analysis of an AB Spectrum
		4.4.3 The Analysis of an A2B2 Spectrum
		4.4.4 Splitting from Magnetically Equivalent Nuclei
	4.5 Practical Considerations
	Problems
	Suggestions for Further Reading
5. Interpretation of Chemical Shifts and Spin-Spin Couplings
	5.1 Introduction
	5.2 Origins of the Chemical Shift
		5.2.1 Molecular Electronic Currents
		5.2.2 Ramsey’s Formula
	5.3 Proton Chemical Shifts
	5.4 Shifts from Other Nuclei
		5.4.1 Fluorine 19F
		5.4.2 Carbon 13C
		5.4.3 Nitrogen 14N and 15N
		5.4.4 Other Nuclei
		5.4.5 Solvent Effects
	5.5 The Origin of Nuclear Spin-Spin Coupling
	5.6 Proton Spin-Spin Coupling
	5.7 Molecular Structure Studies by NMR
	Problems
	Suggestions for Further Reading
6. ESR Spectra of Organic Radicals in Solution
	6.1 The Spin Hamiltonian: Hyperfine Splitting
	6.2 Sets of Equivalent Protons
	6.3 Hyperfine Patterns from Other Nuclei
	6.4 Mechanism of the Hyperfine Coupling
		6.4.1 The Unpaired Spin Density
		6.4.2 Indirect Coupling Through a C-H Bond
		6.4.3 McConnell’s Relation
		6.4.4 Hyperconjugation
	6.5 Spin Distributions in Alternant Hydrocarbon Ions
		6.5.1 Delocalized Molecular Orbitals
		6.5.2 Substituted Benzene Anions
		6.5.3 The Pairing of Electronic States
	6.6 Negative Spin Densities in Odd Alternant Radicals
	6.7 Hyperfine Splitting from 13C and 14N Nuclei
		6.7.1 Carbon 13
		6.7.2 Nitrogen 14
	6.8 Applications of ESR to Solution Chemistry
	Problems
	Suggestions for Further Reading
7. ESR of Trapped Organic Radicals in Solids
	7.1 Introduction
	7.2 The Spin Hamiltonian
	7.3 The First-Order ESR Spectrum
	7.4 Second-Order Effects
	7.5 Experimental Determination of the Hyperfine Tensor
	7.6 The Sign of the Electron-Nuclear Dipolar Coupling
	7.7 α-Proton Coupling Tensor
	7.8 Delocalized π-Electron Radicals
	7.9 Hyperfine Coupling from β Protons
	7.10 Hyperfine Tensors of Other Nuclei
		7.10.1 Carbon 13
		7.10.2 Nitrogen 14
		7.10.3 19F Splittings
	7.11 Randomly Oriented Solids
	Problems
	Suggestions for Further Reading
8. ESR of Organic Molecules in Triplet States
	8.1 Introduction
	8.2 Electron Spin-Spin Interaction
	8.3 The Triplet Energy Levels
	8.4 Transitions with Δms = 2
	8.5 Hyperfine Structure
	8.6 Further Studies of Excited Triplet States
	8.7 Organic Molecules with Triplet Ground States
		8.7.1 Methylene and Nitrene Derivatives
		8.7.2 Triplets with One Localized Electron
		8.7.3 π-Electron Triplets
	8.8 Triplet Excitons
	8.9 Radical-Ion Clusters in Solution
	Problems
	Suggestions for Further Reading
9. Theory of the g Tensor and the ESR Spectra of Inorganic Radicals
	9.1 Determination of the g Tensor in Crystals
	9.2 Theory of the g Tensor and the Effective Spin Hamiltonian
	9.3 A Simple Example
	9.4 The g Tensor in Molecules
	9.5 The CO2- Radical
		9.5.1 Experimental Results
		9.5.2 Molecular Orbitals
		9.5.3 Interpretation of the T and g tensors
	9.6 Other Inorganic Radicals
	Problems
	Suggestions for Further Reading
10. ESR of Transition Metal Ions and Complexes
	10.1 Introduction
	10.2 Energy Levels of the d Electrons
		10.2.1 The d Orbitals of a Free Ion
		10.2.2 The Ligand Field Splitting
		10.2.3 Regular and Distorted Complexes
	10.3 General Freatures of the ESR Spectra
	10.4 Kramers’ Theorem
	10.5 The g Tensor in Ions with S=1/2
		10.5.1 The Ti3+ Ion in a Tetrahedral Complex
		10.5.2 The Ti3+ Ion in an Octahedral Complex
	10.6 The Zero-Field Splitting of Triplet States
		10.6.1 The Origin of the Splittings
		10.6.2 Zero-Field Splitting in the V3+ Ion
		10.6.3 The Spin Hamilton
		10.6.4 ESR Measurements of D
	10.7 Ions with Spin S Greater Than One
		10.7.1 Quartet States
		10.7.2 Quintet and Sextet States
		10.7.3 Summary
	10.8 Hyperfine Splitting from the Metal Nucleus
	10.9 Covalent Bonding and Ligand Hyperfine Structure
	10.10 Electron Exchange Coupling
	10.11 The Rare-Earth Ions
	10.12 Spin-Lattice Relaxation
	Problems
	Suggestions for Further Reading
11. Spin Relaxation
	11.1 Introduction
	11.2 Bloch’s Equations
	11.3 The Lorentz Line Shape
	11.4 The Origin of Magnetic Relaxation
	11.5 Nuclear Spin Relaxation in the Water Molecule
		11.5.1 Perturbation Theory
		11.5.2 The Power Spectrum of a Random Force
		11.5.3 The Effect of a Local Field
		11.5.4 Rotational Brownian Motion
		11.5.5 The Calculation of T1 and T2
		11.5.6 Short and Long Correlation Times
	11.6 Other Nuclear Relaxation Mechanisms
		11.6.1 Introduction
		11.6.2 Anisotropic Chemical Shift
		11.6.3 Nuclear Spin-Rotational Coupling
		11.6.4 Electric Quadrupole Couplings
		11.6.5 Unpaired Electron Spins
	11.7 Spin Relaxation of Radicals in Solution
		11.7.1 Relaxation Mechanisms
		11.7.2 Anisotropic g Tensor and Hyperfine Tensor
		11.7.3 Electron Spin Exchange
		11.7.4 Zero-Field Splittings
	Problems
	Suggestions for Further Reading
12. The Study of Molecular Rate Processes
	12.1 The Time Scale of Magnetic Resonance Experiments
	12.2 The Line Shape for a Jumping Spin
	12.3 Chemical Exchange Effects in NMR Spectra
		12.3.1 Hindered Internal Rotation
		12.3.2 Spin Coupled to a Relaxing Nucleus
		12.3.3 Proton Exchange Reactions
	12.4 Rate Effects in ESR Spectra
		12.4.1 Modulation of the Hyperfine Coupling
		12.4.2 Ion-Pairing in Solution
		12.4.3 Electron Transfer Reactions
		12.4.4 Time-Dependent Changes in the Direction of Spin Quantization
	Problems
	Suggestions for Further Reading
13. Nuclear Resonance in Paramagnetic Systems - Double Resonance
	13.1 Introduction
	13.2 The Knight Shift
	13.3 Unpaired Electron Distributions by NMR
	13.4 Relaxation by Paramagnetic Ions in Solution
	13.5 Electron Nuclear Double Resonance
		13.5.1 The Overhauser Effect
		13.5.2 The Solid-State Effect
		13.5.3 ENDOR
	13.6 Spin Decoupling in NMR
	Problems
	Suggestions for Further Reading
Appendixes
	Appendix A. Matrix Elements and Eigenvalues
	Appendix B. Time-Independent Perturbation Theory
	Appendix C. Spin Angular Momentum
	Appendix D. Tensors and Vectors
	Appendix E. Time-Dependent Perturbation Theory
	Appendix F. Calculation of T1 and T2 for a Spin of 1/2
	Appendix G. The Power Spectrum of a Random Function
	Appendix H. The Diffusion Equation for Brownian Motion
	Appendix I. Tensor Averages in a Rotating Molecule
Index