Oxidation of mercury electrodes in the presence of phenyl-mercury, -lead and -bismuth organometallic compounds in dichloromethane

Oxidation processes observed at mercury electrodes in the presence of Ph₂Hg, Ph₃Bi, Ph₃BiCl₂, Ph₄Pb, Ph₃PbCl, Ph₃PbOAc (OAc = acetate), Ph₂PbCl₂ and PhPb(OAc)₃ have been examined. The data obtained, in conjunction with other reports available in the literature, suggest that the majority of organometallic species exhibit oxidation processes at mercury electrodes which involve oxidation of the mercury electrode and alkyl or aryl exchange. In the case of R₄M (M = Pb, Sn), R₃Bi, R₂Cd (R = aryl or alkyl group), pathways involving transfer of the R group to the electrode and formation of cationic and radical intermediates are proposed. In the case of R₂Hg, mercury rich cationic organomercury complexes are produced. If a halide or acetate group is present and the central metal is not mercury, then formation of a mixed metal-mercury organometallic complex and HgX₂ appears to be the favoured pathway. As in the case of the reduction studies at mercury electrodes, products formed after the charge transfer process tend to be reactive and may interact with the electrolyte, electrode and solvent.