Poly[[aqua(μ5-1H-benzimidazole-5,6-dicarboxylato)(μ4-1H-benzimidazole-5,6-dicarboxylato)dibarium] 4.5-hydrate]

Abstract

The polymeric title compound, {[Ba2(C9H4N2O4)2(H2O)]·4.5H2O}n, adopts a layer structure parallel to (001) in which adjacent BaII atoms are connected by two benzimidazole-5,6-dicarboxylate dianions, one functioning in a μ4-bridging mode and the other in a μ5-bridging mode. The Ba atom having water in its coordination environment as well as the Ba atom without water exist in a nine-coordinate polyhedron of O atoms; the geometry is difficult to derive. Lattice water molecules occupy the space between layers and interact with the layers through O—H...O, O—H...N and N—H...O hydrogen bonds. ne of the five lattice water molecules is equally disordered around an inversion centre and shows half-occupancy.