5-Nitro-1-nonyl-1H-benzimidazol-2(3H)-one

In the title molecule, C16H23N3O3, the dihedral angle between the benzimidazole and nitro group planes is 5.34 (9)° and the dihedral angle between the benzimidazole and aliphatic chain mean planes is 73.23 (5)°. The C—C—C—C torsion angles (about 176°) of the nonyl group indicate an all-antiperiplanar conformation. In the crystal, adjacent molecules are linked by pairs of N—H⋯O hydrogen bonds into inversion dimers. These molecules are further connected through C—H⋯O interactions, building tapes parallel to (22).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: GK2342).

Comment
Benzimidazoles are useful intermediates/subunits for the development of molecules of pharmaceutical or biological interest (Gbadamassi et al., 1988). Benzimidazolone and its derivatives are also an important class of bioactive molecules in the field of drugs and pharmaceuticals (Derand et al., 2003). They found potential applications in diverse therapeutic areas including, anti-hypertensives and anti-virals (Badarau et al., 2009;Singh et al., 2000). The structural studies of benzimidazolone, linked to an isopropenyl and nonyl group respectively, have been published by Saber et al. (2010)and Ouzidan et al. (2011).
In the crystal, adjacent molecules are linked by pairs of N-H···O hydrogen bonds into inversion dimers. These molecules are further connected through C-H···O hydrogen bonds into a tape parallel to the (-1 2 2) plane, as schown in Fig. 2 and Table 1.
The residue was separated by chromatography on a column of silica gel with ethyl acetate/hexane (1/2) as eluent. Colorless needle-shaped crystals were isolated when the solvent was allowed to evaporate [(m.p. 392-394 K (ethanol)].

Special details
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness 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 threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) 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.