Poly[diaqua-bis-[μ-1-hy-droxy-2-(imidazol-3-ium-1-yl)ethane-1,1-diyldiphospho-nato]tricopper(II)].

In the title coordination polymer, [Cu3(C5H7N2O7P2)2(H2O)2]n, one CuII atom is five-coordinated by five O atoms from three 1-hy­droxy-2-(imidazol-3-ium-1-yl)ethane-1,1-diyldiphospho­nate (L) ligands in a distorted square-pyramidal geometry. The other CuII atom, lying on an inversion center, is six-coordinated in a distorted octa­hedral geometry by four O atoms from two L ligands and two O atoms from two water mol­ecules. The five-coordinated CuII atoms are linked by phospho­nate O atoms of the L ligands, forming a polymeric chain. These chains are further linked by the six-coordinated Cu atoms into a layer parallel to (\overline{1}01). N—H⋯O and O—H⋯O hydrogen bonds connect the layers into a three-dimensional supra­molecular structure.