ELECTROCHEMICAL, SPECTROSCOPIC AND THEORETICAL-STUDIES OF A SERIES OF1,1'-FERROCENE DICHALCOGENIDO-COMPLEXES OF RHODIUM AND IRIDIUM

The electrochemical behaviour of a series of heterodimetallic 2-metall a-1,3-dichalcogena-[3]ferrocenophanes of general formula Cp(L)M[(EC(5 )-H-4)(2)Fe] (E = S, Se or Te; M = Rh, L = PMe(3); M = Ir, L = PMe(3), PPh(3) or C=N(t)Bu) has been investigated. These complexes undergo tw o successive oxidation steps. In spite of the fact that both metal cen tres are potentially able to lose electrons, EPR spectra and theoretic al considerations suggest that the bridging chalcogen atoms, which are centres of high electron density, also contribute significantly to th e electron-removal processes.