A study of solvent dynamical effects on nonadiabatic electron transfer reaction rates

Abstract

Abstract We have studied rates of nonadiabatic electron transfer reactions (charge separation as well as charge recombination) by considering a one dimensional reaction coordinate and obtaining its equilibrium distribution through basis set expansion, in the form of the Marcus result multiplied by a polynomial in the reaction coordinate. A Smoluchowski equation is proposed for motion along this reaction coordinate and the first and second order rate constants are obtained for charge recombination and charge separation reactions respectively, using model harmonic and anharmonic free energy curves. Although solvent fluctuations have a negligible effect on charge recombination reactions (unless the medium is highly viscous), they have a significant effect on charge separation reactions, except in the barrierless regime.