Crystal structure of 3-(2-hy-droxy-eth-yl)-2-methyl-sulfanyl-6-nitro-3 H-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 mol-ecules and chloride anions. Aromatic π-π stacking inter-actions 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: benzimidazole derivative; crystal structure; hydrogen bonding; π–π inter­actions.

Figure 1

The mol­ecular structure of (I), showing the atomic labelling scheme and displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitrary radius.

Figure 2

The crystal packing of (I), showing the supra­molecular aggregation resulting from the three-dimensional hydrogen-bonded network. Dashed lines indicate hydrogen bonds. H atoms not involved in hydrogen bonding have been omitted for clarity.

Figure 3

The mol­ecular packing of (I), showing the pattern formed by the water mol­ecules hydrogen bonded to the chloride anions.

Figure 4

A view of the crystal packing, showing π–π stacking inter­actions (dashed lines). The brown dots are the centroids of the rings. H atoms have been omitted for clarity.