2-(4-Hy­droxy­phen­yl)-1H-benzimidazol-3-ium chloride monohydrate

The title mol­ecular salt, C₁₃H₁₁N₂O⁺·Cl⁻·H₂O, crystallizes as a monohydrate. In the cation, the phenol and benzimidazole rings are almost coplanar, making a dihedral angle of 3.18 (4)°. The chloride anion and benzimidazole cation are linked by two N⁺—H...Cl⁻ hydrogen bonds, forming chains propagating along [010]. These chains are linked through O—H...Cl hydrogen bonds involving the water mol­ecule and the chloride anion, which form a diamond core, giving rise to the formation of two-dimensional networks lying parallel to (10-2). Two π–π inter­actions involving the imidazolium ring with the benzene and phenol rings [centroid–centroid distances = 3.859 (3) and 3.602 (3) Å, respectively], contribute to this second dimension. A strong O—H...O hydrogen bond involving the water mol­ecule and the phenol substituent on the benzimidazole unit links the networks, forming a three-dimensional structure.