Synthesis, structure, and properties of sulfido-bridged dinuclear tungsten(V) complex of dithiolene, (Pr4N)(2)[W-2(mu-S)(2){S2C2(CO2Et)(2)}(4)]

The reaction of tetrathiotungstate (WS42-) with diethyl acetylenedicarboxyl ate, EtO2CC=CCO2Et, in the presence of dinuclear Pt(III) complex [Pt2Cl2(5- mpyt)(4)] (5-mpyt = 5-methylpyridine-2-thiolato) as an oxidant gave a sulfi de-bridged dinuclear tungsten(V) complex of dithiolene, (Pr4N)(2)[W-2(mu-S) (2){S2C2(CO2Et)(2)}(4)] (1). The absence of an appropriate oxidant in the r eaction system afforded tris(dithiolene) complex (Pr4N)(2)[W{S2C2(CO2Et)(2) }(3)] (2). The complex 1 was characterized structurally and spectroscopical ly. The complex anion in 1 has an edge-shared bioctahedral structure with t wo bridging sulfide ions, W-W distance being 2.9425(7) Angstrom. The fluxio nality of the dithiolene ligand was observed by H-1-NMR even at - 50 degree s C for 1. (C) 2000 Elsevier Science S.A. All rights reserved.