PROTON-INDUCED REDUCTION OF WO42- UNDER SULFIDE-POLYSULFIDE ENVIRONMENT - A NEW ROUTE TO THE SYNTHESIS OF COMPLEXES CONTAINING ((W2S2)-S-V(MU-S)(2))(2-S)(2))(2+) AND (W2O2(MU-S))(6+) CORES(), (W2O2(MU)

Acidification of an alkaline solution containing tungstate, polysulfid e and tetraethylammonium chloride afforded the products (Et(4)N)(2)[W2 S2(mu-S)(2)(S-4)(2)] (1), (Et(4)N)(2)[W2O2(mu-S)(S-2)(4)] (2) and (Et( 4)N)(2)[W2O2(mu-S)(2)(S-4)(2)] (3) depending on the pH of the solution . This method is a new rational and general method of the syntheses of binuclear sulfur bridged oxo- or sulfide-compounds of tungsten Oil or (VI). The X-ray crystal structure of 1 has been determined. The struc ture consists of disordered tetra-ethylammonium cations and binuclear units of the complex anion [W2S12](2-) with the metal atoms displaying distorted square pyramidal geometry. The structural features of all t he complexes are supported or revealed by the IR, electronic and FAB m ass spectroscopic data. Cyclic voltammetric study of (I) shows two irr eversible single step metal centred reduction waves in the potential r ange -1.0 to -1.8 V.