title: 2-Ethyl-1H-imidazole-4-carboxyl-ate monohydrate.
abstract: In the title compound, C(7)H(8)N(2)O(4)·H(2)O, the imidazole N atom is protonated and one of the carboxyl-ate groups is deprontonated, forming a zwitterion. The two carboxyl groups are are approximately coplanar with the imidazole ring [O-C-C-C torsion angles = -176.8 (2) and 2.9 (4)° for one group and -4.6 (3) and 176.4 (2)° for the other] and have an intra-molecular O-H⋯O hydrogen bond between them. The water mol-ecule is linked to the organic mol-ecules via an N-H⋯O hydrogen bonds. Inter-molecular O-H⋯O and N-H⋯O hydrogen bonds are found in the crystal structure.
authors.forename: Shi-Jie
authors.initials: SJ
authors.lastname: Li
authors.forename: Juan-Hua
authors.initials: JH
authors.lastname: Liu
authors.forename: Wen-Dong
authors.initials: WD
authors.lastname: Song
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Li
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Miao