Diaqua-bis-(4-formyl-benzoato-O ¹)bis-(nicotinamide-kN ¹)cobalt(II)

In the title complex, [Co(C₈H₅O₃) ₂(C₆H₆N₂O)₂(H ₂O)₂], the Co^II cation is located on an inversion center and is coordinated by two 4-formyl-benzoate (FB) anions, two nicotinamide (NA) ligands and two water mol-ecules. The four O atoms in the equatorial plane around the Co^II cation form a slightly distorted square-planar arrangement, while the slightly distorted octa-hedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl-ate group and the adjacent benzene ring is 23.91 (9)°, while the pyridine and benzene rings are oriented at a dihedral angle of 88.84 (4)°. The coordinating water mol-ecule links with the carboxyl-ate group via an intra-molecular O-H⋯O hydrogen bond. In the crystal, N-H⋯O, O-H⋯O and weak C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional supra-molecular network. π-π stacking between the parallel benzene rings of adjacent mol-ecules [centroid-centroid distance = 3.8505 (8) Å] may further stabilize the structure. A weak C-H⋯π inter-action also occurs in the crystal.