mer-Diaquabis(1H-imidazole-κN3)-(orotato-κ2N3, O4)nickel(II)

The title mononuclear complex, [Ni(C5H2N2O4)(C3H4N2)2-(H2O)2] or [Ni(HOr)(im)2(H2O)2] (im is imidazole and H3Or is orotic acid, or 2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4carboxylic acid), has been synthesized and the crystal structure determination is reported. The NiII 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.