ELECTROCHEMICAL S-C BOND-CLEAVAGE IN DIMOLYBDENUM THIOLATE THIOETHER-BRIDGED AND BIS(THIOETHER)-BRIDGED COMPLEXES/

The electrochemical behavior of complexes possessing bridging thioethe r ligands, [Mo(2)Cp(2)(CO)(2)(CO)(2)(mu-SMe)(mu-SMe(2))](+) and [Mo(2) Cp(2)(CO)(2)(mu-SMe(2))(2)](2+), is reported. Controlled-potential red uction of the dicarbonyl complexes leads to cleavage of the S-C bond(s ) of the bridging thioether(s). The different electrochemical and chem ical steps producing [Mo(2)Cp(2)(CO)(2)-(mu-SMe)(2)] are presented. Th e reactions of the dicarbonyl complexes with cyanide and isocyanide pr oceed via the substitution of these ligands for CO. In the case of [Mo (2)Cp(2)(CO)(2)(mu-SMe(2))(2)](2+), the reactions with 1 and 2 equiv. isocyanide produce the singly- and disubstituted derivatives, respecti vely. The electrochemical reduction of the cyanide analogs [Mo(2)Cp(2) (CO)(CN)(mu-SMe)(mu-SMe(2))] and [Mo(2)Cp(2)(CO)(CN)(mu-SMe(2))(2)](+) also results in the cleavage of S-C bond(s). These reactions are fast er, and occur at less negative potentials, for the cyanide complexes t han for their dicarbonyl precursors, which shows that S-C bond cleavag e in these types of complexes is promoted by an increase of the electr on density on the Mo2S2 core.