CARBONYL-COMPLEXES OF MOLYBDENUM AND TUNGSTEN WITH FUNCTIONALIZED DIPHOSPHINES - X-RAY CRYSTAL-STRUCTURE OF [(W(CO)3)2(MU-P(C6H4SME-2)2CH2CH2P(C6H4SME-2)2)]

The diphosphine-bridged, binuclear complexes [{M(CO)3}2(mu-diphos)] (M = Mo or W; diphos = mtppm, mtppe or iptppe) have been prepared. Their binuclear structures are established by the X-ray structure of [{W(CO)3}2(mu-mtppe)], in which each tungsten is ligated by three carbonyl groups in a facial arrangement with P,S,S, ligation from the bridging mtppe ligand completing the octahedral geometry [average d(W-S) 2.514(9), d (W-P) 2.420(6) angstrom. The bridged complexes [{M(CO)4}2(mu-dppmpe)] and [{MBr2(CO)2}2(mu-mtppe)] and the mononuclear compounds [M(CO)4(dbtpe)] and [MoBr2(CO)2(mtppe)] are also described.