Radiationless Transitions

Radiationless Transitions is a critical discussion of research studies on the theory and experiments in radiationless transitions.
This book is composed of nine chapters, and begins with discussions on the theory and experiment of photophysical processes of single vibronic levels and/or single rovibronic levels. The subsequent chapters deal with the spectroscopic investigations of intramolecular vibrational relaxation; the dynamics of molecular excitation by light; and the photophysical processes of small molecules in condensed phase. The discussions then shift to the high pressure effects on molecular luminescence and the internal conversion involving localized excitations, presenting one qualitative and one quantitative example, as well as the intersystem crossing with localized excitations. A chapter explores the energy transfer processes that occur after a molecule in solution is excited by light, with an emphasis on solid solutions in which the large amplitude molecular motion is largely quenched. This chapter also looks into the liquid solutions in which the molecules can translate and rotate under the influence of fluctuating forces from the liquid. The concluding chapter focuses on ultrafast processes.
Researchers in the fields of physics, chemistry, and biology will benefit from this book.

Contenu

List of Contributors
Preface
1 Experimental Measurement of Electronic Relaxation of Isolated Small Polyatomic Molecules from Selected States
I. Introduction
II. Theoretical Background
III. Experimental Studies on Small Triatomic and Tetra-Atomic Molecules
IV. Experimental Studies on Six-Atom and Larger Molecules
References
2 Rotational Fine Structure in Radiationless Transitions
I. Introduction
II. The Excited State Rotational Distribution
III. Isolated Molecule Conditions and Collisional Energy Redistribution
IV. Experimental Evidence for a Rotational Effect in Nonradiative Processes
V. Rotational State Matrix Elements and Selection Rules
VI. The Rate Constant for Nonradiative Transitions
VII. Energy Matching in Isolated Molecules
VIII. Vibrational Effects in Nonradiative Transitions
IX. The Decay of a Multilevel System
X. Model Calculations
XI. Conclusion
References
3 On Rotational Effects in Radiationless Processes in Polyatomic Molecules
I. Introduction
II. The Diatomic Molecule Case
III. The Polyatomic Molecule Case
IV. Modeling the Effect of Intermanifold Coriolis Coupling
V. Rotational Effects in Spin-Orbit Coupling
VI. Angular Momentum Conservation in Polyatomic Fragmentation Reactions
VII. Concluding Remarks
Appendix: Tensor and Angular Momentum Algebra
References
4 Vibrational Relaxation of Isolated Molecules
I. Introduction
II. Theoretical Models
III. Experimental Studies
IV Concluding Remarks
Appendix
References
5 Dynamic Aspects of Molecular Excitation by Light
I. Introduction
II. Basic Premises
III. Selective Excitation
IV Spectral Analysis of Coupling Schemes
V. Summary: Perspectives and Predictions
References
6 Spectroscopic and Time Resolved Studies of Small Molecule Relaxation in the Condensed Phase
I. Introduction
II. Spectra and the Physical Interpretation of Molecular Lineshapes
III. Large Amplitude Vibrational and Electronic Motion
IV. Electronic Solvation and Adiabatic Potential Changes
V. Radiationless Transitions Observed by Polarization and Fluorescence Line Narrowing
VI. Direct Vibrational Relaxation
VII. Vibrational Relaxation through Real Intermediate States
VIII. Atomic Relaxation
IX. Vibrational Relaxation in Triatomics
X. Vibrational Energy Transfer
XI. Observation of Missing States
References
7 High Pressure Studies of Luminescence Efficiency
I. Introduction
II. Internal Conversion
III. Intersystem Crossing
IV. Delocalized Excitation-Doped ZnS
V. Energy Transfer
VI. Viscosity Effects on Luminescence Efficiency
References
8 Relaxation of Electronically Excited Molecular States in Condensed Media
I. Introduction
II. Dynamical Effects in Condensed Phases
III. Experimental Methods
IV. Vibrational Relaxation in Optically Excited States
V. Electronic Relaxation
VI. Summary and Prospects
References
9 Some Considerations of Theory and Experiment in Ultrafast Processes
I. Introduction
II. Time Evolution of a Relaxing System
III. Spectral Line Shapes
IV. Vibrational Relaxation
V. Migration of Particles
VI. Memory Function
Appendix I
Appendix II
References
Index