1-Benzyl-3-[(trimethylsilyl)methyl]benzimidazolium chloride monohydrate

The title compound, C18H23N2Si+·Cl−·H2O, was synthesized from 1-[(trimethylsilyl)methyl]benzimidazole and benzyl chloride in dimethylformamide. The benzimidazole ring system is approximately planar, with a maximum deviation of 0.022 (2) Å, and makes an angle of 74.80 (12)° with the phenyl ring. The crystal packing is stabilized by O—H⋯Cl, C—H⋯Cl, C—H⋯O and C—H⋯π interactions between symmetry-related molecules together with π–π stacking interactions between the imidazolium and benzene rings [centroid–centroid distance = 3.5690 (15) Å] and between the benzene rings [centroid–centroid distance = 3.7223 (14) Å].


Comment
Although there are different antibacterial and antifungal drugs used in the treatment of bacterial and fungal infections, some of them have undesirable side effects. In addition, some of them become less effective due to the development of resistance to these drugs (Williams et al., 2002). Therefore, many clinically effective antibacterial and antifungal drugs have become less effective due to the development of resistance to these drugs. Since, benzimidazole compounds have been found to have a broad range of pharmacological activity, many research groups as well as our group have been interested in these type of heterocyclic compounds (Singh et al., 2000;Huang et al. 2006;Turner & Denny, 1996;Lukevics et al., 2001;Galal et al. 2009;Çetinkaya et al., 1996;Küçükbay et al., 1995Küçükbay et al., , 1997Küçükbay et al., , 2003Küçükbay et al., , 2004Küçükbay et al., , 2010Yılmaz & Küçükbay, 2009;Tavman et al., 2005). In recent years, considerable attention has been given to the synthesis of alkylsilyl substituted benzimidazole derivatives because of their properties in cancer therapy. For example, 1-(3-trimethylsilylpropyl)benzimidazole inhibits carcinoma S-180 tumour growth in dose 1 mg.kg -1 by 62% (on ICR mice) (Lukevics et al., 2001). These properties of silylsubstituted benzimidazole compounds, triggered us to synthesis novel trimethylsilyl substituted benzimidazole compounds. The objectives of this study were to synthesize and elucidate the crystal structure of the title compound, 1-benzyl-3-trimethylsilylmethylbenzimidazolium chloride monohydrate, (I).

Experimental
A mixture of 1-trimethylsilylmethylbenzimidazole (1.02 g, 5 mmol) and benzyl chloride (0.60 cm 3 , 5 mmol) in dimethylformamide (5 ml) was refluxed for 3 h. The mixture was then cooled and the volatiles were removed in vacuo. supplementary materials sup-2 Refinement All H atoms attached to C atoms were fixed geometrically and treated as riding with C-H = 0.93 Å (aromatic), 0.96 Å (methyl) and 0.97 Å (methylene) with U iso (H) = 1.2U eq (C) or 1.5U eq (methyl). H atoms of water molecule were located in difference Fourier maps and included in the subsequent refinement using restraints (O-H= 0.83 (1)Å and H···H= 1.40 (2)Å) with U iso (H) = 1.5U eq (O).In the last cycles of refinement, they were treated as riding on the O atoms.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted Rfactors wR and all goodnesses of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.
Cg1 is the centroid of the N1, C6, C1, N2, C7 ring and Cg2 is the centroid of C1 to C6 ring. Offset is the angle between the centroidto-centroid and plane-to-plane vectors. Centroid-centroid plane-plane offset