title: 4-Methyl-pyridinium 2-carb-oxy-4,5-dichloro-benzoate monohydrate.
abstract: In the structure of the 1:1 proton-transfer compound of 4-methyl-pyridine (γ-picoline) with 4,5-dichloro-phthalic acid, C(6)H(8)N(+)·C(8)H(3)Cl(2)O(4) (-)·H(2)O, determined at 200 K, the 4,5-dichloro-phthalate anions are bridged by the water mol-ecule through O-H⋯O(carbox-yl) hydrogen bonds, giving zigzag chains which extend along the c-axis direction. The 4-methyl-pyridinium cations are linked to the chains through single N-H⋯O(water) hydrogen bonds and occupy the voids within the chains in the one-dimensional structure. The anions have the common 'planar' conformation with a short intra-molecular O-H⋯O(carbox-yl) hydrogen bond.
authors.affiliation: Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Graham
authors.initials: G
authors.lastname: Smith
authors.forename: Urs D
authors.initials: UD
authors.lastname: Wermuth