Building a molecular-level picture of the ultrafast dynamics of the charge-transfer-to-solvent (CTTS) reaction of sodide (Na¯)

Abstract

Charge-transfer-to-solvent (CTTS) reactions represent the simplest possible electron-transfer reaction. One of the reasons that such reactions have become the subject of recent interest is that transfer of a CTTS electron from an atomic anion to the solvent involves only electronic degrees of freedom, so that all the dynamics involved in the reaction are those of the solvent. Thus, CTTS reactions provide an outstanding spectroscopic window on the dynamics of the solvent during electron transfer. In this paper, we will review our recent work studying the CTTS reaction of the sodium anion, (Na− or sodide) in a series of ether solvents. By comparing the results of ultrafast spectroscopic pump/probe experiments and mixed quantum/classical molecular dynamics simulations, we work to build a molecular-level picture of how solvent motions control the dynamics of CTTS, including the distance to which the electron is ejected and the rates of both the forward and back electron-transfer reactions.