Diaquabis(4-formylbenzoato-kappa O-1)bis-(nicotinamide-kappa N-1)cobalt(II)

In the title complex, [Co(C8H5O3)(2)(C6H6N2O)(2)(H2O)(2)], the Co II 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 Co II 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 23.91 (9)degrees, while the pyridine and benzene rings are oriented at a dihedral angle of 88.84 (4)degrees The coordinating water molecule links with the carboxylate group via an intramolecular O-H center dot center dot center dot O hydrogen bond. In the crystal, N-H center dot center dot center dot O, O-H center dot center dot center dot O and weak C-H center dot center dot center dot O hydrogen bonds link the molecules into a three-dimensional supramolecular network. pi-pi stacking between the parallel benzene rings of adjacent molecules [centroid-centroid distance = 3.8505 (8) angstrom] may further stabilize the structure. A weak C-H center dot center dot center dot pi interaction also occurs in the crystal.