Diaquabis(4-formylbenzoato-κO1)bis(nicotinamide-κN1)nickel(II)

In the title complex, [Ni(C8H5O3)2(C6H6N2O)2(H2O)2], the NiII cation is located on an inversion center and is coordinated by two 4-formylbenzoate (FB) anions, two nicotinamide (NA) ligands and two water molecules. The four O atoms in the equatorial plane around the NiII cation 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 23.67 (8)°, while the pyridine and benzene rings are oriented at an angle of 89.04 (4)°. The coordinating water molecule links with the carboxylate group via an O—H...O hydrogen bond. In the crystal, N—H...O, O—H...O and weak C—H...O hydrogen bonds link the molecules into a three-dimensional supramolecular network. π–π contacts between benzene rings [centroid–centroid distance = 3.8414 (7) ] may further stabilize the structure. A weak C—H...π interaction also occurs.