title: 4-Meth-oxy-quinolinium-2-carboxyl-ate dihydrate.
abstract: The title hydrated quinoline derivative, C(11)H(9)NO(3)·2H(2)O, crystallizes as a zwitterion in which the quinoline N atom is protonated. The quinoline ring is essentially planar, with a maximum deviation of 0.017 (2) Å. An intra-molecular N-H⋯O hydrogen bond between the protonated N atom and the O atom of the carboxyl-ate group in the zwitterion forms an S(5) ring motif. In the crystal, the zwitterions are connected into inversion dimers via pairs of N-H⋯O and C-H⋯O hydrogen bonds with R(2) (2)(4) and R(1) (2)(6) motifs. The water mol-ecules are connected via O-H⋯O hydrogen bonds, forming supra-molecular chains along the c axis. Furthermore, the chains and the dimers are connected via O-H⋯O hydrogen bonds, forming ladder-like supra-molecular ribbons along the c axis.
authors.affiliation: X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors.forename: Madhukar
authors.initials: M
authors.lastname: Hemamalini
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun