A STATISTICAL STUDY OF THE POTENTIAL DEPENDENCE OF A TRANSFER-COEFFICIENT SUPPORTS THE MARCUS THEORY

Cyclic voltammograms for the reduction of 2-methyl-2-nitropropane at a mercury electrode in acetonitrile solvent have been analyzed carefull y by the ''global'' method. The dependence of the logarithm of the het erogeneous rate constant on the potential is only mildly parabolic, bu t statistical analysis shows that the curvature is nonetheless genuine and cannot be explained by random errors. The sign of the curvature i s that predicted by the Marcus theory and the magnitude of the effect is also compatible with theory. No trend with scan rate is observed in any of the measured kinetic, thermodynamic or transport parameters.