catena-Poly[[(4-formylbenzoato-κO 1)(isonicotinamide-κN 1)zinc(II)]-μ-4-formylbenzoato-κ2 O 1:O 1′]

In the title compound, [Zn(C8H5O3)2(C6H6N2O)]n, the ZnII ion is tetrahedrally coordinated by two formylbenzoate (FB) and one isonicotinamide (INA) ligands while symmetry-related FB ligands bridge adjacent ZnII ions, forming polymeric chains along the b axis. The carboxylate groups in the two FB ions are twisted away from the attached benzene ring by 9.07 (2) and 26.2 (2)°. The two benzene rings of the FB ions are oriented at a dihedral angle of 81.30 (5)°. In the crystal, adjacent polymeric chains interact via N—H⋯O and C—H⋯O hydrogen bonds, π–π contacts between the formylbenzoate rings [centroid–centroid distance = 3.7736 (8) Å] and weak C—H⋯π interactions, forming a three-dimensional network.