title: Zwitterionic 4-carb-oxy-2-(1-methyl-pyridin-1-ium-4-yl)-1H-imidazole-5-carboxyl-ate.
abstract: In the title zwitterionic mol-ecule, C(11)H(9)N(3)O(4), the imidazole and pyridine rings form a dihedral angle of 2.60 (2)°. An intra-molecular O-H⋯O hydrogen bond occurs. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into inversion dimers. Weak inter-molecular C-H⋯O inter-actions further consolidate the crystal packing.
authors.forename: Dao-Sen
authors.initials: DS
authors.lastname: Liu
authors.forename: Jun-Guo
authors.initials: JG
authors.lastname: Fang