Crystal structure of 4-(di-methyl-amino)-pyridinium 4-amino-benzoate dihydrate.

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.