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

In the title complex, [Zn(C₈H₅O₃) ₂(C₆H₆N₂O)₂(H ₂O)₂], the Zn^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 Zn^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 24.13 (8)°, while the pyridine ring and the benzene ring are oriented at a dihedral angle of 88.52 (4)°. The coordinating water mol-ecule links with the carboxyl-ate group via an O-H⋯O hydrogen bond. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds, and a weak C-H⋯π inter-action link the mol-ecules into a two-dimensional network parallel to (010). These networks are linked via C-H⋯O and π-π inter-actions between inversion-related benzene rings [centroid-centroid distance = 3.8483 (7) Å], forming a three-dimensional supra-molecular structure.