Novel nucleophilic reactivity of disulfido ligands coordinated parallel to M-M (M = Rh, Ir) bonds

Reaction of trans-(MCp)(2)(mu-CH(2))(2)Cl(2)] (M = Rh, Ir; Cp = eta(5)-C(5)Me(5)) with Li(2)S(2) afforded the disulfido complexes (MCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] which were easily oxidized by O(2) to give the oxygenated complexes (MCp)(2)(mu-CH(2))(2)(mu-SSO(2)-S:S')]. Although (RhCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] gave a complicated mixture when reacted with CH(2)Cl(2) or CHCl(3), (IrCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] reacted with both CH(2)Cl(2) and CHCl(3) to give the dithioformato complex (IrCp)(2)(mu-CH(2))(2)(mu-S(2)CH-S:S')]Cl and the cyclotetrasulfido complex ((IrCp)(2)(mu-CH(2))(2))(2)(mu-S(4)-S:S':S":S"')]Cl(2). The oxygenated complexes (RhCp)(2)(mu-CH(2))(2)(mu-SSO(2)-S:S')] reacted with hydrocarbyl halides to afford bridging hydrocarbyl thiolato complexes accompanied by the generation of SO(2) gas. These complexes have been characterized by NMR spectroscopy, ESI-MS, and X-ray diffraction.