SYNTHESIS AND CHARACTERIZATION OF HETEROBIMETALLIC COMPLEXES CONTAINING C-S CLEAVED THIOPHENES

The insertion of the 16e(-) fragments [(triphos)MH] into a C-S bond in thiophene, 2,2'-bithiophene or benzo[b] thiophene gives butadienethio late or 2-vinylthiophenolate complexes in which the sulfur atom become s a powerful nucleophile (M = Rh, Ir; triphos = MeC(CH2PPh2)(3)). This sulfur atom is attacked by unsaturated M'(CO)(5) fragments (M' = Cr, Mo, W). As a result, heterobimetallic complexes are obtained in which the CS inserted thiophene bridges the two metal centres via the sulfur atom. The strength of the M'-S bonding interaction increases in the o rder Mo less than or equal to Cr < W. All the compounds were character ized in solution by multinuclear NMR spectroscopy. (C) 1998 Elsevier S cience S.A. All rights reserved.