ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY, cilt.60, 2004 (SCI-Expanded)
The title mononuclear complex, [Ni(C5H2N2O4)(C3H4N2)(2)- (H2O)(2)] or [Ni(HOr)(im)(2)(H2O)(2)] (im is imidazole and H(3)Or is orotic acid, or 2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid), has been synthesized and the crystal structure determination is reported. The Ni-II ion in the complex has a distorted octahedral coordination geometry comprised of one deprotonated pyrimidine N atom and the adjacent carboxylate O atom of the orotate ligand, two tertiary imidazole N atoms and two aqua ligands. An extensive three-dimensional network of OW-H...O and N-H...O hydrogen bonds, and pi-pi and pi-ring interactions are responsible for crystal stabilization.