SYNTHESIS, CHARACTERIZATION AND STRUCTURAL STUDIES OF MONONUCLEAR ANDPOLYNUCLEAR COMPLEXES OF ZINC(II) WITH 1,10-PHENANTHROLINE, 2,2'-BIPYRIDINE AND 4,4'-BIPYRIDINE

Three complexes of the formula [Zn(2,2'-bipy)(CCl3CO2)(2)(H2O)] (1). [ Zn (1,10-phen)(CCl3CO2)(2)(H2O)] (1a) and mu-4,4'-bipy)(4,4-bipy)(2)(C Cl3CO2)(2)(H2O)(4)](n) (2) have been synthesized and characterized by elemental analysis, IR spectra, thermal analysis and single-crystal X- ray diffraction for 1 and 2 and X-ray powder pattern for 1a. The metal coordination in complex 1 is distorted trigonal bipyramidal with N(1) , O(2) and O(5) defining the basal plane, O(3) and N(2) being in apica l positions. The X-ray crystal structure of 2 reveals that the local c oordination round the Zn-II ion is a distorted octahedron, in which Zn (H2O)(4) coordination planes are bridged by 4,4'-bipyridine to form an infinite chain structure. Two 4,4'-bipyridine molecules and two trich loroacetate anions exist in the lattice linked by intermolecular hydro gen bonds to coordinated water molecule. Complexes 1 and 1a have a sim ilar pattern of bonding and showed identical TGA curve and almost simi lar X-ray powder diffractograms. (C) 1997 Elsevier Science Ltd.