Calculation of rate constant of dimerization of an electrochemically generated species

The rate constant for the Dimerization process of an electrochemically generated species (methyl viologen radical cation MV/sup +./), have been determined by linear scan/ cyclic voltammetry technique. Methyl viologen radical cation MV/sup +/, an unstable radical cation, is known to undergo Dimerization process in aqueous solution. Nicholson and Shain theory and equation for E/sub r/C/sub i/ with the appropriate approximation was used for the evaluation of dimerization kinetic parameter(s). The bimolecular rate constant for the dimerization process of methyl viologen radical cation, was found to be 4.3 (+-1.0) x 10/sup 4/ M/sup -1/s/sup -1/ for the E/sub r/C/sub i/ formalism. The results are consistent with the values reported earlier in the literature. (author)