SIMULATION OF ELECTRON-TRANSFER IN POLAR-SOLVENTS - EFFECTS OF NONEQUILIBRIUM INITIAL-STATE PREPARATION

An approximation method recently developed for computing the time evol ution of electronic state populations in nonadiabatically coupled syst ems prepared in nonequilibrium nuclear configurations is applied to a model of a complex chemical system. A master equation formalism is use d to describe an intramolecular electron transfer reaction in a polar fluid which is initiated by injection of an electron onto the donor si te of the electron transfer complex. Time-dependent rate constants are obtained from molecular dynamics simulations based on electrostatic i nteractions between the solvent dipoles and the charge distribution on the electron transfer complex. (Appropriate Lennard-Jones potentials are also included to represent the finite size of the atoms involved.) From these rate constants electronic state populations may easily be obtained, The molecular dynamics data is also utilized in an attempt t o construct an effective harmonic oscillator environment which can sat isfactorily mimic the properties of the actual condensed phase medium. Some difficulties in constructing such an effective oscillator bath i n cases typified by the electron injection scenario are pointed out. ( C) 1996 American Institute of Physics.