Dinuclear Tungsten and Molybdenum Tetracarbonyl Complexes Doubly-Bridged by Bis(phenylthio) alkane Bidentate Ligands

A new series of dinuclear group 6 metal tetracarbonyl complexes containing two bis(phenylthio) alkane ligands symmetrically bridging two M(CO)(4) moieties of the type cis{[ M(CO)(4)](2)(mu-PhS(CH2) nSPh)(2)} [M = W (1), Mo (2); n = 3 (a), 4 (b), 5 (c), 6 (d)] have been prepared by the reaction of the labile complex M(CO)(4)(py)(2) and bis(phenylthio) alkanes (1: 1 molar ratio) in 1,2-dichloroethane solution under mild reaction conditions. The tungsten complexes are air stable as solids and in chlorinated hydrocarbon solution. In contrast, the Mo analogues are air sensitive as solids and should be stored under inert atmosphere.