Poly[[tetraaqua(μ7‐pyridine‐2,3,5,6‐tetracarboxylato)dicadmium(II)] monohydrate]

The title compound, {Cd₂(C₉HNO₈)(H₂O)₄]·H₂O}_n, consists of two crystallographically independent Cd^II cations, one tetrabasic pyridine‐2,3,5,6‐tetracarboxylate (pdtc) anion, four coordinated water molecules and one solvent water molecule. The Cd^II cations have distorted square‐antiprismatic (one pyridine N, six carboxylate O and one water O atom) and octahedral (three carboxylate O and three water O atoms) coordination environments. Each pdtc ligand employs its pyridine and carboxylate groups to chelate and bridge seven Cd^II cations. The square‐antiprismatic coordinated Cd^II cations are linked by pdtc ligands into a lamellar framework structure, while the octahedral coordinated Cd^II cations are bridged by the μ₂‐carboxylate O atoms and the pdtc ligands into a chain network that further joins neighbouring lamellae into a three‐dimensional porous network. The cavities are filled with solvent water molecules that are linked to the host through complex hydrogen bonding.