title: 3-Carb-oxy-quinolin-1-ium-2-carboxyl-ate monohydrate.
abstract: The title compound, C(11)H(7)NO(4)·H(2)O, contains a 3-carb-oxy-quinolin-1-ium-2-carboxyl-ate (qda) zwitterion and one water mol-ecule. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into inversion dimers, and these dimers are further connected by O-H⋯O hydrogen bonds into a three-dimensional supra-molecular architecture. In addition, π-π inter-actions occur between pyridine and benzene rings from different qda ligands [centroid-centroid distance = 3.749 (1) Å] and the dihedral angles of the -CO(2)H and -CO(2) groups to the quinoline system are 8.47 (3) and 88.16 (6)°, respectively.
authors.affiliation: School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013,  People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wang
authors.forename: Chun-Bo
authors.initials: CB
authors.lastname: Liu
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Yan
authors.forename: Shen-Tang
authors.initials: ST
authors.lastname: Wang
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang