SYNTHESIS AND CHARACTERIZATION OF TERNARY L-HISTIDINE COMPLEXES - CRYSTAL-STRUCTURE OF (2,2'-DIPYRIDYL)-(L-HISTIDINATO-N,N',O)COPPER(II) PERCHLORATE 1.5-HYDRATE

A series of ternary complexes of copper(II), cobalt(II) and zinc(II) w ith L-histidine, 1,10-phenanthroline, 2,2'-dipyridyl or imidazole havi ng perchlorate or acetate as counterions were synthesized and characte rized by conventional methods and for [Cu(bipy)(L-hist)]ClO4.1.5H(2)O and X-ray crystal structure was determined. The crystals belong to the monoclinic space group C2 with a = 18.843(3), b = 10.582(2), c = 11.0 20(2)Angstrom, beta = 115.20(10)degrees, Z = 4, R = 0.0535. The struct ure is consistent of [Cu(bipy)(L-hist)](+) cations, perchlorate ions a nd water molecules. The geometry around copper is trigonal bipyramidal with one N,N',O tridentate L-histidine molecule and one 2,2'-dipyridy l ligand, the apical sites are occupied by the alpha-amino nitrogen [C u-N(71) 1.995(8)Angstrom] and by N(11) of 2,2'-dipyridyl [Cu-N(11) 1.9 83(7)Angstrom], the equatorial plane is formed by the N(3) imidazole d elta-nitrogen [Cu-N(3) 2.140(6)Angstrom], O(82) carboxylic oxygen [Cu- O(82) 2.009(5)Angstrom] and N(22) [Cu-N(22) 2.010(7)Angstrom].