Solvent effects in simple fast electron transfer reactions
The kinetics of the one-electron reduction of p-dicyanobenzene and the oxidation of nickelocene have been studied by ac voltammetry in different aprotic solvents at mercury and platinum ultramicroelectrodes. The observed electron transfer rate constants have been corrected for the double-layer effect. The solvent dependences of the electron transfer rate constants and activation enthalpy are interpreted within the context of contemporary theory. The charge transfer process was found to be perfectly adiabatic for both studied systems. Solvent dynamic and Gibbs activation energy effects on the rate constants were also investigated.