A tubular one-dimensional polymer constructed from alternating clusters of europium(III)-water and copper(I) chloride bridged by 4-(pyridin-4-yl)benzoate

A new 3d-4f heterometallic polymer, poly[[aqua-[mu]₃-chlorido-[[mu]₃-4-(pyridin-4-yl)benzoato]tris­[[mu]₂-4-(pyridin-4-yl)benzoato]dicopper(I)erbium(III)] dihydrate], {[Cu₂Er(C₁₂H₈NO₂)₄Cl(H₂O)]·2H₂O}_n, was synthesized by the hydro­thermal reaction of Er₂O₃, CuCl₂·2H₂O and 4-(pyridin-4-yl)benzoic acid in the presence of HClO₄. The asymmetric unit contains one Er³⁺ cation, two Cu⁺ cations, one Cl^- anion, four deprotonated 4-(pyridin-4-yl)benzoate ligands, one coordinated aqua ligand and two solvent water mol­ecules. This tubular one-dimensional polymer is constructed from alternating clusters of europium(III)-water and copper(I) chloride bridged by 4-(pyridin-4-yl)benzoate ligands. Extensive hydrogen-bonding inter­actions involving both the coordinated and the solvent water mol­ecules provide further stabilization to the structure.