SYNTHESIS AND CHARACTERIZATION OF MONOTERTIARY PHOSPHINO COMPLEXES OFNIOBIUM(III) AND TANTALUM(III) CHLORIDE

Dinuclear diamagnetic niobium (III) and tantalum(III) complexes of the type M2Cl6P2 (where M = Nb, Ta; P = monotertiary phosphine) have been synthesised by the ligand exchange reactions of [M2Cl6(SMe2)(3)] (M = Nb or Ta) with monotertiary phosphines viz. diphenyl (p-tolyl)phosphi ne (DPpTP), diphenylpropylphosphine (DPP), tri-p-tolylphosphine (TpTP) , diphenylvinylphosphine (DPVP), ethyldiphenylphospine (EDPP) and trip ropylphosphine (TPP). All these complexes have been characterised by e lemental analyses, IR, H-1 NMR, P-31 NMR, C-13 NMR spectroscopy and ma gnetic moment data.