FORMATION OF A MU-4-METHANEDITHIOLATE BY TRANSFER OF 2 H-ATOMS FROM RE TO A CS2 MOLECULE - SYNTHESIS AND CRYSTAL-STRUCTURE OF [(RE2(MU-H)(CO)8)2(MU-4-S2CH2)]

The reaction of the unsaturated dinuclear molecule [Re2(mu-H)2(CO)8] with CS2 affords in good yield the complex [{Re2(mu-H)(CO)8}2(mu4-S2CH2)], containing a methanedithiolate H2CS2 fragment originated by the transfer of two hydrides, presumably one from each metal complex, to CS2. The molecule has been characterized spectroscopically and by single-crystal X-ray diffraction analysis. The crystals are monoclinic, space group P2(1)/c, with a = 13.559(1), b = 12.502(1), c = 16.718(1) angstrom, beta = 99.26(1)-degrees. The structure was refined on the basis of 2689 significant reflections to a final R value of 0.026. The molecule consists of two Re2(mu-H)(CO)8 units linked by a methanedithiolate ligand. Each sulfur atom bridges two Re atoms belonging to the same dinuclear moiety. The overall idealized symmetry of the molecule is C2. The average Re-Re and Re-S bond lengths are 3.089 and 2.475 angstrom, respectively.