Note: Intro -- ELECTRON PARAMAGNETIC RESONANCE -- CONTENTS -- PREFACE -- ACKNOWLEDGMENTS -- 1 BASIC PRINCIPLES OF PARAMAGNETIC RESONANCE -- 1.1 Introduction -- 1.2 Historical Perspective -- 1.3 A Simple EPR Spectrometer -- 1.4 Scope of the EPR Technique -- 1.5 Energy Flow in Paramagnetic Systems -- 1.6 Quantization of Angular Momenta -- 1.7 Relation Between Magnetic Moments and Angular Momenta -- 1.8 Magnetic Field Quantities and Units -- 1.9 Bulk Magnetic Properties -- 1.10 Magnetic Energies and States -- 1.11 Interaction of Magnetic Dipoles with Electromagnetic Radiation -- 1.12 Characteristics of the Spin Systems -- 1.12.1 The g Factor -- 1.12.2 Characteristics of Dipolar Interactions -- 1.13 Parallel-Field EPR -- 1.14 Time-Resolved EPR -- 1.15 Computerology -- 1.16 EPR Imaging -- References -- Notes -- Further Reading -- Problems -- 2 MAGNETIC INTERACTION BETWEEN PARTICLES -- 2.1 Introduction -- 2.2 Theoretical Considerations of the Hyperfine Interaction -- 2.3 Angular-Momentum and Energy Operators -- 2.3.1 Spin Operators and Hamiltonians -- 2.3.2 Electronic and Nuclear Zeeman Interactions -- 2.3.3 Spin Hamiltonian Including Isotropic Hyperfine Interaction -- 2.4 Energy Levels of a System with One Unpaired Electron and One Nucleus with I = ½ -- 2.5 Energy Levels of a System with S = ½ and I = 1 -- 2.6 Signs of Isotropic Hyperfine Coupling Constants -- 2.7 Dipolar Interactions Between Electrons -- References -- Notes -- Further Reading -- Problems -- 3 ISOTROPIC HYPERFINE EFFECTS IN EPR SPECTRA -- 3.1 Introduction -- 3.2 Hyperfine Splitting from Protons -- 3.2.1 Single Set of Equivalent Protons -- 3.2.2 Multiple Sets of Equivalent Protons -- 3.3 Hyperfine Splittings from Other Nuclei with I = ½ -- 3.4 Hyperfine Splittings from Nuclei with I > -- ½ -- 3.5 Useful Rules for the Interpretation of EPR Spectra. , 3.6 Higher-Order Contributions to Hyperfine Splittings -- 3.7 Deviations from the Simple Multinomial Scheme -- 3.8 Other Problems Encountered in EPR Spectra of Free Radicals -- 3.9 Some Interesting π-Type Free Radicals -- References -- Notes -- Further Reading -- Problems -- 4 ZEEMAN ENERGY (g) ANISOTROPY -- 4.1 Introduction -- 4.2 Systems with High Local Symmetry -- 4.3 Systems with Rhombic Local Symmetry -- 4.4 Construction of the g Matrix -- 4.5 Symmetry-Related Sites -- 4.6 EPR Line Intensities -- 4.7 Statistically Randomly Oriented Solids -- 4.8 Spin-Orbit Coupling and Quantum-Mechanical Modeling of g -- 4.9 Comparative Overview -- References -- Notes -- Further Reading -- Problems -- 5 HYPERFINE (A) ANISOTROPY -- 5.1 Introduction -- 5.2 Origin of the Anisotropic Part of the Hyperfine Interaction -- 5.3 Determination and Interpretation of the Hyperfine Matrix -- 5.3.1 The Anisotropic Breit-Rabi Case -- 5.3.2 The Case of Dominant Electron Zeeman Energy -- 5.3.2.1 General Case -- 5.3.2.2 The Case of B ≈ B(hf) -- 5.3.2.3 The Case of B » B(hf) -- 5.4 Combined g and Hyperfine Anisotropy -- 5.5 Multiple Hyperfine Matrices -- 5.6 Systems With I > -- ½ -- 5.7 Hyperfine Powder Lineshapes -- References -- Notes -- Further Reading -- Problems -- 6 SYSTEMS WITH MORE THAN ONE UNPAIRED ELECTRON -- 6.1 Introduction -- 6.2 Spin Hamiltonian for Two Interacting Electrons -- 6.2.1 Electron-Exchange Interaction -- 6.2.2 Electron-Electron Dipole Interaction -- 6.3 Systems with S = 1 (Triplet States) -- 6.3.1 Spin Energies and Eigenfunctions -- 6.3.2 'ΔM(S) = ±2' Transitions -- 6.3.3 Randomly Oriented Triplet Systems -- 6.3.4 Photo-excited Triplet-State Entities -- 6.3.5 Thermally Accessible Triplet Entities -- 6.3.6 Ground-State Triplet Entities -- 6.3.6.1 Carbenes and Nitrenes -- 6.3.6.2 Dianions of Symmetric Aromatic Hydrocarbons. , 6.3.6.3 Inorganic Triplet Species -- 6.4 Interacting Radical Pairs -- 6.5 Biradicals -- 6.6 Systems with S > -- 1 -- 6.7 High-Spin and High-Field Energy Terms -- 6.8 The Spin Hamiltonian: A Summing up -- 6.9 Modeling the Spin-Hamiltonian Parameters -- References -- Notes -- Further Reading -- Problems -- 7 PARAMAGNETIC SPECIES IN THE GAS PHASE -- 7.1 Introduction -- 7.2 Monatomic Gas-Phase Species -- 7.3 Diatomic Gas-Phase Species -- 7.4 Triatomic and Polyatomic Gas-Phase Molecules -- 7.5 Laser Electron Paramagnetic Resonance -- 7.6 Other Techniques -- 7.7 Reaction Kinetics -- 7.8 Astro-EPR -- References -- Notes -- Further Reading -- Problems -- 8 TRANSITION-GROUP IONS -- 8.1 Introduction -- 8.2 The Electronic Ground States of d-Electron Species -- 8.3 The EPR Parameters of d-Electron Species -- 8.4 Tanabe-Sugano Diagrams and Energy-Level Crossings -- 8.5 Covalency Effects -- 8.6 A Ferroelectric System -- 8.7 Some f-Electron Systems -- References -- Notes -- Further Reading -- Problems -- 9 THE INTERPRETATION OF EPR PARAMETERS -- 9.1 Introduction -- 9.2 π-Type Organic Radicals -- 9.2.1 Anions and Cations of Benzene and Some of its Derivatives -- 9.2.2 Anions and Cations of Polyacenes -- 9.2.3 g Factors of π Radicals -- 9.2.4 Origin of Proton Hyperfine Splittings -- 9.2.5 Sign of the Proton Hyperfine Splitting Constant -- 9.2.6 Methyl Proton Hyperfine Splittings and Hyperconjugation -- 9.2.7 Hyperfine Splitting from Nuclei Other than Protons -- 9.2.8 One-Dimensional Chain Paramagnets -- 9.3 σ-Type Organic Radicals -- 9.4 Triplet States and Biradicals -- 9.5 Inorganic Radicals -- 9.6 Electrically Conducting Systems -- 9.6.1 Metals -- 9.6.2 Metals Dissolved in Ammonia and Amine Solutions -- 9.6.3 Semiconductors -- 9.6.4 Graphitic Compounds -- 9.7 Techniques for Structural Estimates from EPR Data -- 9.7.1 The Newman Superposition Model. , 9.7.2 The Pseudo-cube Method -- 9.7.3 Distances from Parameter D -- 9.7.4 Eatons' Interspin-Distance Formula -- 9.7.5 Summary -- References -- Notes -- Further Reading -- Problems -- Appendix 9A Hückel Molecular-Orbital Calculations -- HMO References -- HMO Problems -- 10 RELAXATION TIMES, LINEWIDTHS AND SPIN KINETIC PHENOMENA -- 10.1 Introduction -- 10.2 Spin Relaxation: General Aspects -- 10.2.1 Spin Temperature and Boltzmann Distribution -- 10.2.2 Spin Dynamics -- 10.2.3 Mechanisms for τ(1) -- 10.3 Spin Relaxation: Bloch Model -- 10.3.1 Magnetization in a Static Magnetic Field -- 10.3.2 Addition of an Oscillating Magnetic Field -- 10.3.3 Rotating Frame -- 10.3.4 Steady-State Solutions of Bloch Equations -- 10.4 Linewidths -- 10.4.1 Homogeneous Broadening -- 10.4.2 Inhomogeneous Broadening -- 10.5 Dynamic Lineshape Effects -- 10.5.1 Generalized Bloch Equations -- 10.5.2 Other Theoretical Models -- 10.5.3 Examples of Line-Broadening Mechanisms -- 10.5.3.1 Electron-Spin Exchange -- 10.5.3.2 Electron Transfer -- 10.5.3.3 Proton Transfer -- 10.5.3.4 Fluxional Motion -- 10.5.4 Linewidth Variation: Dynamic Hyperfine Contributions -- 10.5.4.1 Single Nucleus -- 10.5.4.2 Multiple Nuclei -- 10.5.5 Molecular Tumbling Effects -- 10.5.5.1 Dipolar Effects -- 10.5.5.2 Spin-Rotation Interaction -- 10.5.6 General Example -- 10.6 Longitudinal Detection -- 10.7 Saturation-Transfer EPR -- 10.8 Time Dependence of the EPR Signal Amplitude -- 10.8.1 Concentration Changes -- 10.8.2 Chemically Induced Dynamic Electron Polarization -- 10.9 Dynamic Nuclear Polarization -- 10.10 Bio-Oxygen -- 10.11 Summary -- References -- Notes -- Further Reading -- Problems -- 11 NONCONTINUOUS EXCITATION OF SPINS -- 11.1 Introduction -- 11.2 The Idealized B(1) Switch-on -- 11.3 The Single B(1) Pulse -- 11.4 Fourier-Transform EPR and FID Analysis -- 11.5 Multiple Pulses. , 11.6 Electron Spin-Echo Envelope Modulation -- 11.7 Advanced Techniques -- 11.8 Spin Coherence and Correlation -- References -- Notes -- Further Reading -- Problems -- 12 DOUBLE-RESONANCE TECHNIQUES -- 12.1 Introduction -- 12.2 A Continuous-Wave ENDOR Experiment -- 12.3 Energy Levels and ENDOR Transitions -- 12.4 Relaxation Processes in Steady-State ENDOR(5) -- 12.5 CW ENDOR: Single-Crystal Examples -- 12.5.1 The F Centers in the Alkali Halides -- 12.5.2 Metal-Ion Tetraphenylporphyrins -- 12.6 CW ENDOR in Powders and Non-Crystalline Solids -- 12.7 CW ENDOR in Liquid Solutions -- 12.8 Pulse Double-Resonance Experiments -- 12.9 Electron-Electron Double Resonance (ELDOR) -- 12.10 Optically Detected Magnetic Resonance -- 12.11 Fluorescence-Detected Magnetic Resonance -- References -- Notes -- Further Reading -- Problems -- 13 OTHER TOPICS -- 13.1 Apologia -- 13.2 Biological Systems -- 13.3 Clusters -- 13.4 Charcoal, Coal, Graphite and Soot -- 13.5 Colloids -- 13.6 Electrochemical EPR -- 13.7 EPR Imaging -- 13.8 Ferromagnets, Antiferromagnets and Superparamagnets -- 13.9 Glasses -- 13.10 Geologic/Mineralogic Systems and Selected Gems -- 13.10.1 Amethyst -- 13.10.2 Beryl and Chrysoberyl -- 13.10.3 Diamond -- 13.10.4 Emerald -- 13.10.5 Opal -- 13.10.6 Rock Crystal (α-Quartz) -- 13.10.7 Ruby -- 13.10.8 Sapphire -- 13.10.9 Topaz -- 13.10.10 Tourmaline -- 13.10.11 Turquoise -- 13.10.12 Zircon -- 13.11 Liquid Crystals -- 13.12 "Point" Defects -- 13.12.1 Insulators -- 13.12.1.1 Alkali Halides -- 13.12.1.2 Oxides -- 13.12.2 Semiconductors -- 13.13 Polymers -- 13.14 Radiation Dosage and Dating -- 13.15 Spin Labels -- 13.16 Spin Traps -- 13.17 Trapped Atoms and Molecules -- APPENDIX A MATHEMATICAL OPERATIONS -- A.1 Complex Numbers -- A.2 Operator Algebra -- A.2.1 Properties of Operators -- A.2.2 Eigenvalues and Eigenfunctions -- A.3 Determinants. , A.4 Vectors: Scalar, Vector, and Outer Products.