Crystal structure of poly[di-chlorido-(μ-2,5-di-carb-oxy-benzene-1,4-di-carboxyl-ato-κ2O1:O4)bis-[μ-4'-(pyridin-3-yl)-4,2':6',4''-terpyridine-κ2N1:N4']dizinc].

In the title polymeric ZnII complex, [Zn2(C10H4O8)Cl2(C20H14N4)2]n, the ZnII cations are bridged by both 2,5-di­carb­oxy­benzene-1,4-di­carboxyl­ate dianions and 4′-(pyridin-3-yl)-4,2′:6′,4′′-terpyridine ligands, forming ladder-like polymeric chains propagating along [1-10]. The Cl− anion further coordinates the ZnII cation to complete a distorted tetra­hedral environment. In the 4′-(pyridin-3-yl)-4,2′:6′,4′′-terpyridine ligand, the three sideward pyridine rings are twisted with respect to the central pyridine ring by 39.27 (12), 14.89 (13) and 3.36 (13)°, respectively. In the crystal, classical O—H⋯N hydrogen bonds and weak C—H⋯O and C—H⋯Cl hydrogen bonds link the chains into a three-dimensional supra­molecular architecture. π–π stacking is observed between the pyridine and benzene rings of neighbouring polymeric chains, with a centroid-to-centroid distance of 3.7280 (14) A.