A one-dimensional triaqua­europium(III)–1H,3H-benzimidazol-3-ium-5,6-dicarboxyl­ate–sulfate polymeric structure

In the title coordination polymer, catena-poly[[[triaqua­europium(III)]-bis­(μ-1H,3H-benzimidazol-3-ium-5,6-dicarb­oxyl­ato-κ(3) O (5),O (5′):O (6))-[triaqua­europium(III)]-di-μ-sulfato-κ(3) O:O,O′;κ(3) O,O′:O′] hexahydrate], [Eu(2)(C(9)H(5)N(2)O(4))(2)(SO(4))(2)(H(2)O)(6)]·6H(2)O}(n), the 1H,3H-benzimidazol-3-ium-5,6-dicarb­oxy­l­ate ligand is protonated at the imidazole group (H(2)bdc). The Eu(III) ion is coordinated by nine O atoms from two H(2)bdc ligands, two sulfate anions and three water mol­ecules, displaying a bicapped trigonal prismatic geometry. The carboxyl­ate groups of the H(2)bdc ligands and the sulfate anions link the Eu(III) ions, forming a chain along [010]. These chains are further connected by N—H⋯O and O—H⋯O hydrogen bonds and π–π inter­actions between the imidazole and benzene rings [centroid–centroid distances = 3.997 (4), 3.829 (4) and 3.573 (4) Å] into a three-dimensional supra­molecular network.