Synthesis, structure and magnetism of a new imidazolate-bridged binuclear complex [Ni2(im)(phen)4]•(NO3)3•3H2O

In C2H5OH and H2O as solvent, Ni(NO3)(2)(.)6H(2)O, imidazole and phenanthroline (phen) acting as starting materials, the binuclear complex [Ni-2(im)(phen)(4)](.)(NO3)(3)(.)3H(2)O was synthesized. Its structure has been studied by X-ray diffraction. The complex crystallizes in triclinic, space group P-1 with a = 13.294(5) Angstrom, b = 13.723(5) Angstrom, c = 16.823(2) Angstrom, alpha = 89.67(2)degrees, 0 = 69.11(13)degrees, gamma = 63.43(3)degrees, V = 2520.8(13) Angstrom(3) and Z = 2. The structure consists of the dimeric [Ni-2(im)(phen)(4)](3+) ion with the imidazolate ion bridging the two Ni(phen)(2) moieties. The lattice contains three water molecules and three nitrate anions. Each Ni(H) ion is five-coordinate, and the coordination geometry, is distortional square pyramid. Cryomagnetic. investigations (4.5-300K) reveal an antiferromagnetic coupling between two Ni(II) ions in the complex with J = -30.43 cm(-1), g = 1.98. The UV-Vis-NIR and IR spectra of the complex were determined and assigned. (C) 2002 Elsevier Science B.V. All rights reserved.