2-[3-(1H-Benzimidazol-2-yl)prop­yl]-1H-benzimidazol-3-ium 3,4,5-tri­hydroxy­benzoate–1,3-bis­(1H-benzimidazol-2-yl)propane–ethyl acetate (2/1/2.94): co-crystallization between a salt, a neutral mol­ecule and a solvent

The chemical formula of the title compound, 2C(17)H(17)N(4) (+)·2C(7)H(5)O(5) (−)·C(17)H(16)N(4)·2.94C(4)H(8)O(2), was established by X-ray diffraction of a single-crystal obtained by reacting 1,3-bis­(benzimidazol-2-yl)propane (L) and gallic acid (HGal) in ethyl acetate. The mol­ecular structure can be described as a salt (HL)(+)(Gal)(−) co-crystallized with a mol­ecule L, with a stoichiometric relation of 2:1. Moreover, large voids in the crystal are filled with ethyl acetate, the amount of which was estimated by using a solvent mask during structure refinement, affording the chemical formula (HL (+)·Gal(−))(2)·L·(C(4)H(8)O(2))(2.94). The arrangement of components in the crystal is driven by O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds rather than by π–π or C—H⋯π inter­actions. In the crystal, mol­ecules and ions shape the boundary of cylindrical tunnels parallel to [100] via R (rings) and D (discrete) supra­molecular motifs. These voids, which account for about 28% of the unit-cell volume, contain disordered solvent mol­ecules.