John K. Howie

Oxidation-deduction chemistry of oxo- and sulphldo-bridged binuclear molybdenum(V) complexes in aprotic media☆

Abstract The electrochemistry of a series of oxo- and sulphido-bridged binuclear molybdenum(V) complexes in dimethyl sulphoxide, acetonitrile and dimethylformamide has been studied by use of cyclic voltammetry and controlled potential electrolysis. The solution properties of these complexes and their electrolysis products have also been investigated by UV-visible spectrophotometry. Redox mechanisms are proposed on the basis of the electrochemical data and analysis of the electrolysis products. Comparisons are made between the redox properties of oxo- and sulphido-bridged molybdenum complexes. Dioxo-bridged complexes in general are reduced by a two-electron process, while monoxo- and sulphido-bridged compounds are reduced by successive one-electron processes. The results, which indicate the conditions that stabilise mixed oxidation state dimers, may provide insight into the chemistry of biological molybdenum.