title: 3-(4-Carb-oxy-5-carboxyl-ato-1H-imidazol-2-yl)pyridin-1-ium monohydrate.
abstract: In the zwitterionic mol-ecule of the title compound, C(10)H(7)N(3)O(4)·H(2)O, one carboxyl group is deprotonated and the pyridine N atom is protonated. The pyridinium and imidazole rings form a dihedral angle of 5.23 (1)°. An intramolecular O-H⋯O hydrogen bond occurs. In the crystal, inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds link the zwitterions and water mol-ecules into sheets parallel to (102).
authors.forename: Guang-Jun
authors.initials: GJ
authors.lastname: Liu
authors.forename: Guang-Wang
authors.initials: GW
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Gao