Poly[tetraaqua(5-hydroxypyridin-1-ium-3-carboxylato-kappa O-3)tris(mu-oxalato-kappa O-4(1), O-2 : O-1 ', O-2 ') dieuropium(III)]

In the title compound, [Eu2(C6H5NO 3)2(C2O4)3(H 2O)4]n, the EuIII atom is bonded to one O atom from a monodentate 5-hydroxypyridin-1-ium-3-carboxylate ligand, six O atoms from three oxalate ligands and two water molecules, exhibiting a highly distorted tricapped trigonal geometry. Three independent oxalate ligands, each lying on an inversion center, bridge the EuIII atoms, forming a brickwall-like layer parallel to (001), which is stabilized by intralayer O - H⋯O hydrogen bonds. The layers are further linked through interlayer O - H⋯O and N - H⋯O hydrogen bonds and π-π interactions between the pyridine rings [centroid-centroid distance = 3.5741 (14) Å] into a three-dimensional supramolecular network.