Electron spin resonance study of the autoxidation of hydrazine, hydroxylamine, and cysteine catalysed by the cobalt(II) chelate complex of 3,10,17,24-tetrasulphophthalocyanine

Abstract

The title complex [Co^II(tspc)] is an efficient catalyst for the oxidation of hydrazine, hydroxylamine, or cysteine in aqueous solution by molecular oxygen. E.s.r. measurements have been made on frozen aqueous solutions containing the complexes of [Co^II(tspc)] with dioxygen, hydrazine, and hydroxylamine as a precursor to similar measurements on aqueous solutions containing the [Co^II(tspc)] substrate complexes exposed to molecular oxygen. The oxidation of hydrazine and hydroxylamine involves the initial formation of a 1 : 1 adduct between [Co^II(tspc)] and the substrate which reacts with molecular oxygen to yield the oxidation products and [Co^II(tspc)]. In the case of cysteine the oxidation process involves an electron-transfer reaction resulting in the formation of [Co^I(tspc)]^– and cystine.