The kinetics of reductive electron transfer to the methyl viologen dication (MV2+) to form a radical cation (MV+.) have been investigated in the presence of outer-sphere charge-transfer complexation. The solvent was water and the electrode substrate was platinum. It was found that the rate of electron transfer does not depend on the equilibrium constant of complexation, but rather on the rate of dissociation of the solution-phase complex. Accordingly, it has been suggested that the reaction of a CE reaction xith at least a partial dissociation of the complex, to separate the acceptor and donor components-prior to the successful electron-transfer reaction.