Poly[[triaqua-(μ(3)-4-oxidopyridine-2,6-dicarboxyl-ato)europium(III)] monohydrate].

In the title coordination polymer, {[Eu(C(7)H(2)NO(5))(H(2)O)(3)]·H(2)O}(n), the Eu(III) atom is eight-coordinated by a tridentate 4-oxidopyridine-2,6-dicarboxyl-ate (hpc) trianion, two monodentate hpc anions and three water mol-ecules, forming a distorted bicapped trigonal-prismatic coordination geometry. The hpc ligands bridge adjacent Eu(III) ions, forming infinite double chains. Adjacent chains are further connected by hpc ligands into sheets. O-H⋯O hydrogen bonds then generate a three-dimensional supra-molecular framework.