Condensed–Phase Molecular Spectroscopy and Photoph ysics

ANNE MYERS KELLEY earned a BS in chemistry from the University of California, Riverside, in 1980 and a PhD in biophysical chemistry from the University of California, Berkeley, in 1984. Following postdoctoral work at the University of Pennsylvania, she held faculty positions at the University of Rochester (1987 1999) and Kansas State University (1999 2003) before becoming one of the founding faculty at the University of California, Merced, in 2003. Her primary research area has been resonance Raman spectroscopy, linear and nonlinear, but she has also worked in several other areas of spectroscopy including single-molecule and line-narrowed fluorescence, four-wave mixing, and time-resolved methods. She is a Fellow of the American Physical Society and the American Association for the Advancement of Science.

Preface xi 1 Review of Time-Independent Quantum Mechanics 1 1.1 States, Operators, and Representations 1 1.2 Eigenvalue Problems and The Schrodinger Equation 4 1.3 Expectation Values, Uncertainty Relations 6 1.4 The Particle in a Box 7 1.5 Harmonic Oscillator 9 1.6 The Hydrogen Atom and Angular Momentum 12 1.7 Approximation Methods 15 1.8 Electron Spin 18 1.9 The Born-Oppenheimer Approximation 22 1.10 Molecular Orbitals 22 1.11 Energies and Time Scales, Separation of Motions 25 Further Reading 26 Problems 27 2 Electromagnetic Radiation 31 2.1 Classical Description of Light 31 2.2 Quantum Mechanical Description of Light 35 2.3 Fourier Transform Relationships Between Time and Frequency 38 2.4 Blackbody Radiation 40 2.5 Light Sources for Spectroscopy 42 References and Further Reading 44 Problems 44 3 Radiation-Matter Interactions 47 3.1 The Time-Dependent Schrodinger Equation 47 3.2 Time-Dependent Perturbation Theory 50 3.4 Interaction of Matter with the Classical Radiation Field 54 3.5 Interaction of Matter with the Quantized Radiation Field 59 References and Further Reading 63 Problems 64 4 Absorption and Emission of Light 67 4.1 Einstein Coefficients for Absorption and Emission 67 4.2 Other Measures of Absorption Strength 69 4.3 Radiative Lifetimes 72 4.4 Oscillator Strengths 73 4.5 Local Fields 73 Further Reading 74 Problems 75 5 System-Bath Interactions 79 5.1 Phenomenological Treatment of Relaxation and Lineshapes 79 5.2 The Density Matrix 86 5.3 Density Matrix Methods in Spectroscopy 90 5.4 Exact Density Matrix Solution for a Two-Level System 95 References and Further Reading 98 Problems 98 6 Symmetry Considerations 103 6.1 Qualitative Aspects of Molecular Symmetry 103 6.2 Introductory Group Theory 104 6.3 Finding the Symmetries of Vibrational Modes of a Certain Type 109 6.4 Finding the Symmetries of All Vibrational Modes 111 Further Reading 113 Problems 113 7 Molecular Vibrations and Infrared Spectroscopy 115 7.1 Vibrational Transitions 115 7.2 Diatomic Vibrations 117 7.3 Anharmonicity 118 7.4 Polyatomic Molecular Vibrations; Normal Modes 121 7.5 Symmetry Considerations 127 7.6 Isotopic Shifts 130 7.7 Solvent Effects on Vibrational Spectra 130 References and Further Reading 135 Problems 135 8 Electronic Spectroscopy 139 8.1 Electronic Transitions 139 8.2 Spin and Orbital Selection Rules 141 8.3 Spin-Orbit Coupling 143 8.4 Vibronic Structure 143 8.5 Vibronic Coupling 148 8.6 The Jahn-Teller Effect 151 8.7 Considerations in Large Molecules 152 8.8 Solvent Effects on Electronic Spectra 154 Further Reading 159 Problems 160 9 Photophysical Processes 163 9.1 Jablonski Diagrams 163 9.2 Quantum Yields and Lifetimes 166 9.3 Fermi s Golden Rule for Radiationless Transitions 167 9.4 Internal Conversion and Intersystem Crossing 167 9.5 Intramolecular Vibrational Redistribution 173 9.6 Energy Transfer 179 9.7 Polarization and Molecular Reorientation in Solution 182 References and Further Reading 186 Problems 186 10 Light Scattering 191 10.1 Rayleigh Scattering from Particles 191 10.2 Classical Treatment of Molecular Raman and Rayleigh Scattering 193 10.3 Quantum Mechanical Treatment of Molecular Raman and Rayleigh Scattering 195 10.4 Nonresonant Raman Scattering 204 10.5 Symmetry Considerations and Depolarization Ratios in Raman Scattering 206 10.6 Resonance Raman Spectroscopy 207 References and Further Reading 211 Problems 211 11 Nonlinear and Pump-Probe Spectroscopies 215 11.1 Linear and Nonlinear Susceptibilities 215 11.2 Multiphoton Absorption 216 11.3 Pump-Probe Spectroscopy: Transient Absorption and Stimulated Emission 219 11.4 Vibrational Oscillations and Impulsive Stimulated Scattering 225 11.5 Second Harmonic and Sum Frequency Generation 227 11.6 Four-Wave Mixing 232 11.7 Photon Echoes 232 References and Further Reading 234 Problems 234 12 Electron Transfer Processes 239 12.1 Charge-Transfer Transitions 239 12.2 Marcus Theory 243 12.3 Spectroscopy of Anions and Cations 247 References and Further Reading 248 Problems 248 13 Collections of Molecules 251 13.1 Van Der Waals Molecules 251 13.2 Dimers and Aggregates 252 13.3 Localized and Delocalized Excited States 253 13.4 Conjugated Polymers 256 References 259 Problems 259 14 Metals and Plasmons 263 14.1 Dielectric Function of a Metal 263 14.2 Plasmons 266 14.3 Spectroscopy of Metal Nanoparticles 268 14.4 Surface-Enhanced Raman and Fluorescence 270 References and Further Reading 274 Problems 275 15 Crystals 277 15.1 Crystal Lattices 277 15.2 Phonons in Crystals 281 15.3 Infrared and Raman Spectra 284 15.4 Phonons in Nanocrystals 286 References and Further Reading 287 Problems 287 16 Electronic Spectroscopy of Semiconductors 291 16.1 Band Structure 291 16.2 Direct and Indirect Transitions 296 16.3 Excitons 296 16.4 Defects 298 16.5 Semiconductor Nanocrystals 298 Further Reading 302 Problems 302 Appendices A Physical Constants, Unit Systems and Conversion Factors 305 B Miscellaneous Mathematics Review 309 C Matrices and Determinants 313 D Character Tables for Some Common Point Groups 317 E Fourier Transforms 321 Index 323