The crystal and molecular structures of some platinum phosphine complexes and tervalent antimony salts.

The X-ray analysis of inorganic compounds from two unrelated fields are reported in this thesis. The first study is concerned with the stereochemistry adopted by compounds whose valence shells contain seven electron pairs; in the specific case studied there were six bonding and one non-bonding electron pairs. The structure of the complex anion [Sb (C2O4)3]s-, as revealed from an X-ray analysis of its potassium and ammonium salts, is severely distorted, with all six Sb-0 bonds directed towards one side of the antimony atom. This distortion is presumably due to the presence of a stereochemically active lone pair of electrons, which may be allocated to a vacant axial site in the coordination sphere. The second group of compounds studied are all platinum-phosphine complexes. The complex bis (triphenylphosphine) platinum (o) trifluoro- acetonitrile may be prepared by the reaction of trifliioroacetonitrite with bis (triphenylphosphine) platinum (o) trajis-stilbene. The structure determination of this compound revealed the presence of a 'IT bonded nitrile group. The geometry of the unsaturated ligand has undergone considerable distortion upon coordination to the metal. If trifluoroacetonitrile is reacted with tetrakis triphenyl- phosphine platinum (o) under aqueous conditions a series of products may be obtained. The structure of one of these products, assigned the stoichiometiy P?3Pt(CF3CN)3H2 has been determined. The complex does not contain a trimerised trifluoroacetonitrile unit, and models based upon the stoichiometry P?3Pt(CF3CN)3NHn are suggested. The crystal structure determination of a reported carbonyl fluoride complex of platinum (P?3)2Pt(CO)2F2 has been undertaken. The analysis revealed that the compound is bis (triphenylphosphine) platinum (O) dicarbonyl, (P?3)2Pt(CO)2, but the individual atoms of the carbonyl groups were poorly defined and associated Tfith high temperature factors.