Radical reductions of Cu(II)-penicillamine complexes: Evidence for a Cu(II)-disulphide anion intermediate

Abstract

In basic solution Cu(II) ions form planar complexes of stoichiometry Cu(II)•L2 with penicillamine molecules, where both the nitrogen and sulphur atoms of the thiol [(NH2)CH(CO2−)C(CH3)2S−] are involved in the coordination. The rates of reduction of this complex by the formate radical and the thiyl radical of penicillamine have been measured by pulse radiolysisThe rate constant for reaction [14] has been found to be 1.2 ± 0.2 × 108M−1 s−1[Formula: see text]For the thiyl radical, which is not inherently reducing, reduction must involve the [Formula: see text] anion complex.