2-[3-(1H-Benzimidazol-2-yl)prop-yl]-1H-benzimidazol-3-ium 3,5-dicarb-oxy-benzoate-benzene-1,3,5-tricarb-oxy-lic acid-water (1/1/1)

The title compound, C₁₇H₁₇N₄ ⁺·C₉H₅O₆ ^-·C₉H₆O₆·H ₂O, contains a protonated 2,2′-(1,3-propanedi-yl)bis-(1H- benzimidazole) cation, a deprotonated benzene-1,3,5-tricarb-oxy-lic acid anion, a neutral benzene-1,3,5-tricarb-oxy-lic acid mol-ecule and a water mol-ecule, which are linked together through N - H⋯O, O - H⋯O and weak C - H⋯O hydrogen bonds into almost double sheets parallel to (4 ). These hydrogen-bonded sheets are packed in the crystal with the formation of centrosymmetric voids of 25.5 ų, which are filled by the water mol-ecules.