3-Carboxymethyl-1,3-benzimidazolium-1-acetate monohydrate

The title compound, C11H10N2O4·H2O, has a zwitterionic structure, in which the benzimidazole ring system is planar, with a maximum deviation of 0.007 (3) Å. The carboxyl/carboxylate groups adopt a trans configuration. In the crystal structure, intermolecular O—H...O hydrogen bonds involving the hydroxy/oxide O atoms link the molecules into a one-dimensional chain. These chains are further linked by O—H...O hydrogen bonds involving the water molecules into a two-dimensional network. π–π contacts between the benzimidazole rings [centroid–centroid distance = 3.5716 (4) Å] lead to the formation of a three-dimensional supramolecular structure