Thermal and photochemical reactions of organocobaloximes with diphenyl disulphide and diphenyl diselenide

Abstract

Alkyl- and benzyl-bis(dimethylglyoximato)pyridinecobalt(III) complexes react with diphenyl disulphide or diphenyl diselenide, thermally and photochemically, to give good yields of alkyl or benzyl phenyl sulphides or selenides. Chiral alkylcobalt(III) complexes react to give racemic alkyl phenyl sulphides or selenides. Allyl- and propadienyl-bis(dimethylglyoximato)pyridinecobalt(III) complexes react similarly to give the thermodynamically more stable allyl, propadienyl, or propynyl phenyl sulphides or selenides. These reactions are interpreted in terms of free radical processes in which organic radicals formed as a result of thermal, photochemical, or chemically induced homolysis of the organocobalt complex, attack the diphenyl dichalcogenide to give the product organo phenyl chalcogenide. No evidence could be obtained for the direct attack of phenylthyl or phenylselenyl radicals on the organic ligand of the organocobalt complexes, though this process cannot be exluded in the case of allyl-cobalt complexes.