Abstract: | Coordination polymers constructed from metal ions and organic ligands have attracted considerable attention owing to their diverse structural topologies and potential applications. Ligands containing carboxylate groups are among the most extensively studied because of their versatile coordination modes. Reactions of benzene‐1,4‐dicarboxylic acid (H2BDC) and pyridine (py) with ZnII or CoII yielded two new coordination polymers, namely, poly[(μ4‐benzene‐1,4‐dicarboxylato‐κ4O:O′:O′′:O′′′)(pyridine‐κN)zinc(II)], [Zn(C8H4O2)(C5H5N)]n, (I), and catena‐poly[aqua(μ3‐benzene‐1,4‐dicarboxylato‐κ3O:O′:O′′)bis(pyridine‐κN)cobalt(II)], [Co(C8H4O2)(C5H5N)2(H2O)]n, (II). In compound (I), the ZnII cation is five‐coordinated by four carboxylate O atoms from four BDC2− ligands and one pyridine N atom in a distorted square‐pyramidal coordination geometry. Four carboxylate groups bridge two ZnII ions to form centrosymmetric paddle‐wheel‐like Zn2(μ2‐COO)4 units, which are linked by the benzene rings of the BDC2− ligands to generate a two‐dimensional layered structure. The two‐dimensional layer is extended into a three‐dimensional supramolecular structure with the help of π–π stacking interactions between the aromatic rings. Compound (II) has a one‐dimensional double‐chain structure based on Co2(μ2‐COO)2 units. The CoII cations are bridged by BDC2− ligands and are octahedrally coordinated by three carboxylate O atoms from three BDC2− ligands, one water O atom and two pyridine N atoms. Interchain O—H…O hydrogen‐bonding interactions link these chains to form a three‐dimensional supramolecular architecture. |