An overview of continuum models for nonequilibrium solvation: Popular theories and new challenge

Abstract

The effect of solvent on the electron transfer (ET) and spectral shifts has been the focus of experimental and theoretical studies and a key quantity in these studies is the solvent reorganization energy. There are a number of theoretical models toward the evaluation of nonequilibrium solvation free energy that were proposed decades ago and have been applied widely. In the past decade, however, we revisited the original theoretical derivations and identified a serious defect in the popular nonequilibrium solvation models which causes the significant overestimation of solvent reorganization energy and hence predicts a much lowed rate constant for ET in some cases. A rigorous derivation by means of contrained equilibrium principle of thermodynamics was subsequently conducted for the study of nonequilibrium solvation. In this review, the author outlined the intimate interplays among the representative models and analyzed what the possible problem could be. The key idea presented in our recent papers was highlighted. The constrained equilibrium principle in classical thermodynamics and its application to the nonequilibrium solvation were detailed, and a few argumentative examples in literature were taken for the validation of our theory. © 2015 Wiley Periodicals, Inc.