A novel two‐dimensional framework based on unprecedented cadmium(II) chains

The bent ligand 4‐(1H‐1,2,4‐triazol‐1‐yl)methyl]benzoic acid (HL) has been used to create the novel two‐dimensional coordination polymer polyμ₂‐aqua‐μ₂‐chlorido‐{μ₂‐4‐(1H‐1,2,4‐triazol‐1‐yl)methyl]benzoato}cadmium(II)], Cd(C₁₀H₈N₃O₂)Cl(H₂O)]_n, under hydrothermal reaction of HL with cadmium chloride. The crystallographically unique Cd atom is seven‐coordinated in an approximately pentagonal–bipyramidal environment of two carboxylate O atoms, two water O atoms, two Cl atoms and one triazole N atom. A notable feature is the presence of zigzag ...Cd...Cd... inorganic chains, in which neighboring Cd^II ions are doubly bridged by pairs of μ₂‐Cl atoms and μ₂‐H₂O ligands in an alternating fashion. To the authors' knowledge, this is the first example containing this bridging mode in a cadmium(II) framework. The chains are connected to one another through the bridging L⁻ ligand into a two‐dimensional undulating network. All of the two‐dimensional nets stack exactly together in an …AA… stacking sequence along the crystallographic b axis. Neighboring layers are further linked into a three‐dimensional framework via interlayer hydrogen‐bonding interactions.