COMPLEXES OF DISTIBINOMETHANE LIGANDS - PART-2 - CHROMIUM, MOLYBDENUMAND TUNGSTEN CARBONYL DERIVATIVES OF DISTIBINOMETHANE LIGANDS

Substituted Group 6 carbonyl complexes of the distibinomethane ligands Ph2SbCH2SbPh2 (dpsm) and Me2SbCH2SbMe2 (dmsm) of types [M(CO)(5)(eta( 1)-dpsm)] (M = Cr, Mo or W), [(OC)(5)M(mu-dpsm)M(CO)(5)] (M not equal Mo), [(OC)(5)M(mu-dmsm)M(Co)(5)], [(OC)(4)M(mu-dpsm)(2)M(CO)(4)], [(OC )(4)M(mu-dmsm)(2)M(CO)(4)] and fac-[M(CO)(3)(eta(1)-dpsm)(3)] have bee n isolated and characterised by chemical analysis, IR, NMR (H-1, C-13- {H-1}, Mo-95) spectroscopy and FAB mass spectrometry. The crystal stru ctures of [W(CO)(5)(dpsm)], [{W(CO)(5)}(2)(dpsm)], [{W(CO)(4)(dpsm)}(2 )] and [{W(CO)(4)(dmsm)(2)}] have been determined. Complexes of eta(1) -dmsm have been observed but are too unstable to isolate in a pure sta te. Both the ligands function as monodentate or bridging bidentates in the complexes characterised, but no examples with chelated distibinom ethanes have been prepared. Comparisons are drawn with complexes of re lated diphosphine ligands.