title: Crystal structure of 4-(di-methyl-amino)-pyridinium 4-amino-benzoate dihydrate.
abstract: In the title hydrated mol-ecular salt, C7H11N2 (+)·C7H6NO2 (-)·2H2O, the cation is protonated at the pyridine N atom and the dihedral angle between the benzene ring and the CO2 (-) group in the anion is 8.5 (2)°. In the crystal, the cation forms an N-H⋯O hydrogen bond to the anion and the anion forms two N-H⋯O hydrogen bonds to adjacent water mol-ecules. Both water mol-ecules form two O-H⋯O hydrogen bonds to carboxyl-ate O atoms. In combination, these hydrogen bonds generate a three-dimensional network and two weak C-H⋯π inter-actions are also observed.
authors.affiliation: Department of Physics, Presidency College, Chennai 600 005, India.
authors.forename: A
authors.initials: A
authors.lastname: Thirunavukkarasu
authors.affiliation: Department of Physics, Presidency College, Chennai 600 005, India.
authors.forename: A
authors.initials: A
authors.lastname: Silambarasan
authors.affiliation: Department of Physics, Presidency College, Chennai 600 005, India.
authors.forename: R Mohan
authors.initials: RM
authors.lastname: Kumar
authors.affiliation: Directorate of Collegiate Education, Govt. of Tamil Nadu, Chennai 600 006, India.
authors.forename: P R
authors.initials: PR
authors.lastname: Umarani
authors.affiliation: Department of Physics, CPCL Polytechnic College, Chennai 600 068, India.
authors.forename: G
authors.initials: G
authors.lastname: Chakkaravarthi
keywords: 4-(di­methyl­amino)­pyridinium; 4-amino­benzoate; crystal structure; hydrate; hydrogen bonding