Reports: ND651191-ND6: Reorganization Energy for Electron Transfer Reactions in Ionic Fluids

Xueyu Song, Iowa State University

Electron transfer process in ionic fluid is studied under linear response approximation with a molecule Debye-Hückel theory. The reorganization energy which serves as a central concept in Marcus' theory, could be derived from the free energy profile for reactant or product. As a consequence of linear response, the free energy profile is a quadratic function of a reaction coordinate such as the vertical energy gap. Furthermore, it is noted that the fluctuation and mean value of the vertical energy gap are related to each other by the fluctuation-dissipation relation, and hence both of them could be used to evaluate the reorganization energy. Our molecule Debye-Hückel theory could be used to calculate the mean value of the vertical energy gap, from which the reorganization energy is calculated.

Out theory is applied to electron transfer process in a simple molten salt system as well as in room temperature ionic liquids, where the reorganization energy from molecule dynamics simulations could be well reproduced by our theory prediction,  which demonstrates the accuracy of our theory.

A manuscript based this work is in the process of submitting to Journal of Chemical Physics.