The distance dependence of electron transfer reactions: rate maxima and rapid rates at large reactant separations

Abstract

It has been found that the dependences of the electronic coupling element and of the solvent reorganization energy on distance have important implications for intramolecular electron transfers and for the forward and back reaction rates and cage-escape yields in light-induced electron-transfer processes. An equation is presented for the net second order rate constant for bimolecular transfer. A derived difference in the optimum distance for the forward and back reactions is pointed out to have important implications for the formulation of steady-state quenching schemes and for the interpretation of cage-escape yields.