catena‐Poly[[[(di‐2‐pyridylamine‐κ2N2,N2′)copper(II)]‐μ‐benzene‐1,3‐dicarboxylato‐κ3O1,O1′:O3] monohydrate], a zigzag coordination polymer with strong π–π interactions

The novel title coordination polymer, {Cu(C₈H₄O₄)(C₁₀H₉N₃)]·H₂O}_n, synthesized by the slow‐diffusion method, takes the form of one‐dimensional zigzag chains built up of Cu^II cations linked by benzene‐1,3‐dicarboxylate (ipht) anions. An exceptional characteristic of this structure is that it belongs to a small group of metal–organic polymers where ipht is coordinated as a bridging tridentate ligand with monodentate and chelate coordination of individual carboxylate groups. The Cu^II cation has a highly distorted square‐pyramidal geometry formed by three O atoms from two ipht anions and two N atoms from a di‐2‐pyridylamine (dipya) ligand. The zigzag chains, which run along the b axis, further construct a three‐dimensional metal–organic framework via strong face‐to‐face π–π interactions and hydrogen bonds. A solvent water molecule is linked to the different carboxylate groups via hydrogen bonds. Thermogravimetric and differential scanning calorimetric analyses confirm the strong hydrogen bonding.