A new one‐dimensional Cd II coordination polymer incorporating 2,2′‐(1,2‐phenylene)bis(1 H ‐imidazole‐4,5‐dicarboxylate)

Imidazole‐4,5‐dicarboxylic acid (H 3 IDC) and its derivatives are widely used in the preparation of new coordination polymers owing to their versatile bridging coordination modes and potential hydrogen‐bonding donors and acceptors. A new one‐dimensional coordination polymer, namely catena ‐poly[[diaquacadmium(II)]‐μ 3 ‐2,2′‐(1,2‐phenylene)bis(1 H ‐imidazole‐4,5‐dicarboxylato)], [Cd(C 16 H 6 N 4 O 8 ) 0.5 (H 2 O) 2 ] n or [Cd(H 2 Phbidc) 1/2 (H 2 O) 2 ] n , has been synthesized by the reaction of Cd(OAc) 2 ·2H 2 O (OAc is acetate) with 2,2′‐(1,2‐phenylene)bis(1 H ‐imidazole‐4,5‐dicarboxylic acid) (H 6 Phbidc) under solvothermal conditions. In the polymer, one type of Cd ion (Cd1) is six‐coordinated by two N atoms and two O atoms from one H 2 Phbidc 4− ligand and by two O atoms from two water molecules, forming a significantly distorted octahedral CdN 2 O 4 coordination geometry. In contrast, the other type of Cd ion (Cd2) is six‐coordinated by two N atoms and two O atoms from two symmetry‐related H 2 Phbidc 4− ligands and by two O atoms from two symmetry‐related water molecules, leading to a more regular octahedral coordination geometry. The Cd1 and Cd2 ions are linked by H 2 Phbidc 4− ligands into a one‐dimensional chain which runs parallel to the b axis. In the crystal, the one‐dimensional chains are connected through hydrogen bonds, generating a two‐dimensional layered structure parallel to the ab plane. Adjacent layers are further linked by hydrogen bonds, forming a three‐dimensional structure in the solid state.