CHARGE-TRANSFER COMPLEXES OF THE VIOLOGENS - EFFECTS OF COMPLEXATION AND THE RATE OF ELECTRON-TRANSFER TO METHYL VIOLOGEN

The kinetics of reductive electron transfer to the methyl viologen dic ation (MV2+) to form a radical cation (MV+.) have been investigated in the presence of outer-sphere charge-transfer complexation. The solven t was water and the electrode substrate was platinum. It was found tha t the rate of electron transfer does not depend on the equilibrium con stant of complexation, but rather on the rate of dissociation of the s olution-phase complex. Accordingly, it has been suggested that the rea ction of a CE reaction xith at least a partial dissociation of the com plex, to separate the acceptor and donor components-prior to the succe ssful electron-transfer reaction. (C) 1997 Elsevier Science Ltd.