Benzimidazolium 3,5-dicarb­oxy­benzoate trihydrate

Cocrystallization of benzimidazole with benzene 1,3,5-tricarb­oxy­lic acid in slightly basic medium afforded the title compound, C(7)H(7)N(2) (+)·C(9)H(5)O(6) (−)·3H(2)O, in which one of the imidazole N atom is protonated and one carb­oxy­lic group of aromatic acid is deprotonated. In the crystal structure, inter­molecular N—H⋯O hydrogen-bonding connects the two organic components into dimers, which are further linked into a three-dimensional network by O—H⋯O and N—H⋯O inter­actions between the water mol­ecules and the dimers.