Theoretical investigations of vibrational energy relaxation in solution

A rigorous theoretical treatment of vibrational energy relaxation in solution has been developed based on a general theory of dynamics of chemical reactions in solution.; Algorithms which permit the construction of a physically realistic generalized Langevin equation of motion for the energy relaxation dynamics of a specified normal mode coordinate immersed at infinite dilution in monatomic and molecular solvent are developed. These algorithms permit the construction, from equilibrium solute-solvent pair correlation functions, of the liquid state frequency of the normal mode, {dollar}omegasb{lcub}l{rcub}{dollar}, and of the Gaussian model approximation to the autocorrelation function {dollar}langletilde{lcub}cal F{rcub}(t)tilde{lcub}cal F{rcub}ranglesb{lcub}o{rcub}{dollar} of the fluctuating force exerted by the solvent on the solute normal mode.; From these quantities, one may compute the vibration energy relaxation time {dollar}Tsb1{dollar} of the solute normal mode and assess the relative importance of the various energy dissipation pathways, solute vibration {dollar}leftrightarrow{dollar} solvent, solute vibration {dollar}leftrightarrow{dollar} solute translation {dollar}leftrightarrow{dollar} solvent, and solute vibration {dollar}leftrightarrow{dollar} solute translation, solute rotation {dollar}leftrightarrow{dollar} solvent.; Numerical studies are presented for the prototype case of a diatomic solute in a monatomic solvent along with studies of more chemically interesting systems in molecular solvents. The study of VER in neat {dollar}Osb2{dollar} is presented.