Date Published: May 01, 2009
Publisher: International Union of Crystallography
Author(s): Tuncer Hökelek, Hakan Dal, Barış Tercan, Özgür Aybirdi, Hacali Necefoğlu.
The title NiII complex, [Ni(C8H8NO2)2(C6H6N2O)2(H2O)2], is centrosymmetric with the Ni atom on an inversion center. The molecule contains two 4-methylaminobenzoate (MAB) and two nicotinamide (NA) ligands and two coordinated water molecules, all ligands being monodentate. The four O atoms in the equatorial plane around the Ni atom form a slightly distorted square-planar arrangement, while the slightly distorted octahedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxylate group and the adjacent benzene ring is 2.09 (14)°, while the pyridine and benzene rings are oriented at a dihedral angle of 66.15 (4)°. In the crystal structure, intermolecular O—H⋯O and N—H⋯O hydrogen bonds link the molecules into a three-dimensional network.
For general background to transition metal complexes with biochemically active ligands, see: Antolini et al. (1982 ▶); Bigoli et al. (1972 ▶); Nadzhafov et al. (1981 ▶); Shnulin et al. (1981 ▶); Krishnamachari (1974 ▶). For related structures, see: Hökelek et al. (1995 ▶, 1997 ▶, 2007 ▶, 2008 ▶); Hökelek & Necefoğlu (1996 ▶, 1997 ▶, 2007 ▶).