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 diffe rent aprotic solvents at mercury and platinum ultramicroelectrodes. Th e observed electron transfer rate constants have been corrected for th e double-layer effect. The solvent dependences of the electron transfe r rate constants and activation enthalpy are interpreted within the co ntext 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 invest igated.