Crystal Structure, Spectroscopic Characterization, and Electrochemical and Thermal Stability Properties of a Dinuclear Nickel(II)Complex

A new nickel(II) complex Ni-2(L)(2)(2,2.-bipy)(2) center dot 5.5H(2)O with methy-bicycle[2.2.1] hept5-ene-2,3-dicarboxylic acid (H2L) and 2,2.-bipyridine (2,2.-bipy) as ligands has been synthesized in the mixed solvent DMF and water (v: v = 5: 2). It crystallizes in the triclinic space group P1 with a = 10.414(2), b = 12.884(3), c = 16.176(4) angstrom, alpha = 70.715(5), beta = 80.599(5),. = 77.383(6)angstrom, V = 1989.4(8)angstrom(3), D-c = 1.531 g/cm(3), Z = 2, F(000) = 958, GOOF = 1.028, the final R = 0.0808 and wR = 0.2036. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two nickel ions are bridged by two mu(2)-eta(1):eta(0) 3-carboxylate groups of L(2-)anions. The coordination environment of Ni(II) ion is NiN2O3, giving a distorted square pyramidal geometry. The thermal stability and electrochemical properties of the complex were investigated.