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

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(?-PhS(CH2)nSPh)2} [M = W (1), Mo (2); n = 3 (a), 4 (b), 5 (c), 6 (d)] have been prepared and characterized.