MONONUCLEAR AND BINUCLEAR COPPER(II) COMPLEXES OF BENZENE-1,2-DIOXYACETIC ACID (BDOAH(2)) - X-RAY CRYSTAL-STRUCTURES OF [CU(BDOA)(C6H5NH2)(2)]2C6H5NH2 AND [CU(BDOA)(BIPY)(4)] BDOA-CENTER-DOT-8.66H(2)O (C6H5NH2-ANILINE, BIPY=2,2'-BIPYRIDINE)

The copper(II) complex [Cu(bdoa)(H2O)(2)] (1; bdoaH(2) = benzene-1,2-d ioxyacetic acid) reacts with aniline in an ethanol-water mixture to gi ve [Cu(bdoa) (C6H5NH2)(2)]2C6H5NH2 (2) The X-ray crystal structure of 2 shows the asymmetric unit to contain two mononuclear [Cu(bdoa)(C6H5N H2)(2)] units and a solvate aniline molecule. Each copper(II) atom has essentially square planar coordination and is bonded to the nitrogen atoms of two trans aniline molecules and a single oxygen atom from eac h of the two carboxylate moieties of the bdoa(2-) ligand. The ether ox ygen atoms of the bdoa(2-) bond only weakly. to the metal, and one of the metals also interacts weakly with the solvate aniline. Compound 1 reacts with 2,2'-bipyridine (bipy) to form the binuclear copper(II) co mplex [Cu-2(bdoa)(bipy)(4)]bdoa . 8.66H(2)O (3). The X-ray crystal str ucture of 3 shows a discrete [Cu-2(bdoa)(bipy)(4)](2+) dication, an un complexed bdoa(2-) dianion and water molecules linked by O-H ... O hyd rogen bonding. The dication has two-fold crystallographic symmetry, an d the coordination of the unique copper atom is N4O2 distorted octahed ral. Only one of the carboxylate oxygens is strongly bonded and the ot her forms a weak interaction with the metal. Spectral, magnetic, condu ctivity, voltammetry and thermogravimetric data for the complexes are given.