Electrochemical study of dinuclear organometallic complexes containing a metal-metal bond

Electrochemical and ESR techniques were used to determine electrochemical oxidation and reduction schemes for Mn2(CO)10, [Mo(CO)3Cp]2, [W(CO)3Cp]2 and their associated monoanions and monocations. The mechanisms were similar for all three metal systems. The dimers are oxidized and reduced via an ECE mechanism, the metal-metal a bond being broken after the first electron exchange. The monoanions are oxidized to the radical monomer which may either dimerize to give back the dimer or be oxidized by a second electron to give the monocation. A similar competition between dimerization and electron transfer was observed during reduction of the monocations which passed through a radical species. [...]