SYNTHETIC AND STRUCTURAL STUDIES ON ORGANOMOLYBDENUM-BISMUTH HALIDE-COMPLEXES

The reactions between either BiBr2Ph and Na/K[Mo(CO)307-C5H5)], [BiPh{ Mo(CO)3(eta-C5H5)}2] and BiBr2Ph, or BiBr, and BiPh3 and [Bi{Mo(CO)3(e ta-C5H5)}3] afford the complex [BiBrPh{Mo(CO)3(eta-C5H5}}] 1 which has been characterised by X-ray crystallography. Complex 1 comprises a bi smuth centre bonded to a bromine atom, a phenyl group and a Mo(CO)3(et a-C5H5) fragment together with a longer secondary intermolecular inter action between a bromine from an adjacent molecule which results in a one-dimensional polymeric structure. Addition of a source of bromide a nion to 1 affords the anionic complex [BiBr2Ph{MO(CO)3(eta-C5H5)}]- 3- although prolonged reaction results in the complex [BiBr2{Mo(CO)3(eta -C5H5)}2]- 5- which was characterised by X-ray crystallography as its [Ph4P]+ salt. Complex 5- comprises a mononuclear bismuth centre bonded to two bromine atoms and two Mo(CO)3(eta-C5H5) fragments in a geometr y which lies between equatorially vacant trigonal bipyramidal and tetr ahedral. The complex [PPN]2[Bi2Cl6{Mo(CO)3(eta-C5H5)]2] 8 has also bee n synthesised and characterised by X-ray crystallography. A dimeric di anion is observed which can be viewed as two edge-shared square-based pyramids with chlorine atoms in the basal planes and Mo(CO)3(eta-C5H5) fragments in the apical positions on opposite sides of the Bi2Cl6 pla ne.