Oxidative Synthesis, Optical Resolution, and Characterization of Mixed Sulfenato and Sulfinato Cobalt(III) Complexes

Twelve new mixed sulfenato and sulfinato cobalt(III) complexes were prepared via successive H2O2 oxidation of [Co(SCH2CH2NH2)3], [Co{SCH2CH(COOCH3)NH2}3], and related complexes. These oxidation products, [Co(sulfenato-N,S)n(sulfinato-N,S)3−n] (n=3, 2, 1, and 0), were optically resolved by means of column chromatography or preferential crystallization of a diastereomeric molecular compound with d-tartaric acid. The mixed sulfenato and sulfinato complexes show characteristic variation of absorption spectra with the change of “n” in [Co(sulfenato-N,S)n(sulfinato-N,S)3−n] (n=3, 2, 1, and 0). It is concluded that the (R) configuration of the sulfenato group is more stable than the (S) one in the fac(S)-Λ-[Co(sulfenato-N,S)n(sulfinato-N,S)3−n].