A MOLECULAR-MODEL FOR AN ELECTRON-TRANSFER REACTION AT THE WATER 1,2-DICHLOROETHANE INTERFACE

The structure, energetics and dynamics involved in a model electron transfer reaction at the interface between water and 1,2-dichloroethane are investigated by molecular dynamics computer simulation. The molecular model provides information about the spatial localization of the redox pair and its orientation at the interface, which is generally missing from other treatments of the problem. Although each center is mainly solvated by one of the liquids, due to surface roughness, significant contributions from both Liquids to the electrostatic potential fluctuations at each site are observed. The solvent free energy curves for the reaction are computed by an umbrella sampling procedure and are shown to be in very good agreement with the linear response approximation. Solvent relaxation following photochemically induced ''vertical'' electron transfer is shown to contain components from both liquids on different time scales.