Crystal structure of 3-(2-hydroxyethyl)-2-methylsulfanyl-6-nitro-3H-benzimidazol-1-ium chloride monohydrate

Abstract

In the cation of the title hydrated molecular salt, C10H12N3O3S+·Cl−·H2O, the benzimidazolium ring system is almost planar (r.m.s. deviation = 0.006 Å) and the nitro group is inclined at an angle of 4.86 (9)° to this plane. In the crystal, C—H...O hydrogen bonds form centrosymmetric R22(20) dimers and these are further aggregated through N—H...O and O—H...Cl hydrogen bonds involving the water molecules and chloride anions. Aromatic π–π stacking interactions are also found between two parallel benzene rings or the benzene and imidazolium rings, with centroid–centroid distances of 3.5246 (9) and 3.7756 (9) Å, respectively. Analysis of the bond lengths and comparison with related compounds show that the nitro substituent is not involved in conjugation with the adjacent π-system and hence has no effect on the charge distribution of the heterocyclic ring.

Keywords

• crystal structure
• benzimidazole derivative
• hydrogen bonding
• π–π interactions