DICARBONYL DITHIO LIGAND COMPLEXES OF TUNGSTEN(II)

Reaction of LWI(CO)(n) [L = hydrotris(3,5-dimethylpyrazol-1-yl)borate, n = 2, 3] with NH4[S2PR2] [R = OEt, OPri, (-)-mentholate (R), Ph] in acetonitrile or THF results in the formation of the dithio ligand com plexes LW(S2PR2-S)(CO)(2). The yellow-orange, diamagnetic complexes ex hibit IR spectra featuring two nu(CO) bands at ca. 1950 and 1840 cm(-1 ) and H-1-NMR spectra consistent with fluxional behavior in solution. Crystallographic characterisation of LW{S2P(OPri)(2)-S}(CO)(2) reveale d a six-coordinate, distorted octahedral complex composed of a tungste n center coordinated by a monodentate dithiophosphate ligand, two cis carbonyl ligands, and a facial, tridentate L ligand. Unlike analogous complexes bearing strictly monodentate sulfur donor ligands, the LW(S2 PR2)(CO)(2) complexes undergo reactions with oxygen atom donors to pro duce (carbonyl)oxo complexes of the type LWO(S2PR2-S)(CO). (C) 1998 El sevier Science S.A. All rights reserved.