ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, vol.66, 2010 (SCI-Expanded)
The title Ni-II complex, [Ni(C8H7O2)(2)(C6H6N2O)(2)(H2O)(2)], is centrosymmetric with the Ni atom located on an inversion center. The molecule contains two 4-methylbenzoate (PMB) 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 26.15 (10)degrees, while the pyridine and benzene rings are oriented at a dihedral angle of 87.81 (4)degrees. In the crystal structure, intermolecular O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds link the molecules into a three-dimensional network. The pi-pi contact between the benzene rings [centroid-centroid distance = 3.896 (1) angstrom] may further stabilize the crystal structure. A weak C-H center dot center dot center dot pi interaction involving the pyridine ring also occurs.