Nature of the transient species in the one-electron oxidation of diethyl dithiocarbamate as studied by pulse radiolysis

Abstract

One-electron oxidation of the diethyl dithiocarbamate (DDC) anion by oxidising radicals such as ˙OH, N3˙, Br2˙–etc. has been studied employing the pulse radiolysis technique. The transient species absorbing in the visible region (λmax 570 nm) has been identified as the dimer anion radical formed by the interaction of the initial neutral radical (Et2NCS2˙) with the parent anion. This species was found to be rather unreactive towards other solutes and decayed, with second-order kinetics, to give disulfiram. The reaction of disulfiram with hydrated electrons (e–aq) gave rise to the same transient spectrum as obtained in the case of one-electron oxidation of DDC. The reaction of e–aq with DDC at pH 9 gave a transient spectrum with λmax 340 nm which has been attributed to a carbon-centred radical dianion (Et2NCS2˙2–).