The Oxidation of Dithiocarbamate Anion by Substitution Inert Metal Complexes

Abstract

The kinetics of oxidation of dithiocarbamate anions to thiuram disulfides in aqueous acetone by {Fe(CN)₆}³- and 11 other substitution inert metal complexes have been investigated. Outer-sphere electron transfer, resulting in the formation of dithiocarbamate thio radicals, is the rate determining step. A Marcus cross reaction treatment allows an estimate for the redox potential for the dithiocarbamate radical/anion couple. For diethyldithiocarbamate, E º(edtc/edtc-) = 425 ± 33 mV v.s.c.e. and the outer-sphere electron self-exchange rate constant is log k_ex = 7.0 ± 0.3. A comparison with thiophenolate oxidation is also given.