2-(3-Chlorophenyl)-4,5-dihydro-1H-imidazole

In the title compound, C9H9ClN2, a substituted imidazoline, the six- and five-membered rings are twisted from each other, making a dihedral angle of 17.07 (5)°. In the crystal structure, a short Cl⋯Cl [3.3540 (3) Å] interaction is observed. Neighbouring molecules are linked together by intermolecular N—H⋯N hydrogen bonds into a one-dimensional infinite chain along the [101] direction and short Cl⋯Cl contacts link the chains into a three-dimensional network. There is also a significant π-stacking interaction between the planar sections of the six- and five-membered rings.


Comment
Imidazoline derivatives are of great importance because they exhibit significant biological and pharmacological activities including antihypertensive (Blancafort, 1978), antihyperglycemic (Chan, 1993), antidepressive (Vizi, 1986), antihypercholesterolemic (Li et al., 1996) and antiinflammatory (Ueno et al., 1995) properties. These compounds are also used as catalysts and synthetic intermediates in some organic reactions (Corey & Grogan, 1999). Due to these important applications of imidazolines, here we report the crystal structure of the title compound, (I).
In the title compound ( Fig. 1), bond lengths (Allen et al., 1987) and angles are within the normal ranges and are comparable with the related structures (Stibrany et al., 2004;Kia et al., 2008). The six-and five-membered rings are not coplanar and are twisted from each other by a dihedral angle of 18.07 (5)°. The interesting feature of the crystal structure is the short Cl···Cl [3.3540 (3) Å] (Table 1) which is shorter than the sum of the van der Waals radius of this atom. In the crystal structure ( Fig. 2), neighbouring molecules are linked together by intermolecular N-H···N hydrogen bonds (Table 2) into 1-D infinite chains along the [1 0 1] direction and short Cl···Cl contacts link these chains into a 3-D network. There is also a significant π-stacking interaction between the planar sections associated with C1-C3-C4-C5-C6 and C7 of the six-and five-membered rings respectively (Table 1).

Experimental
The synthetic method was based on the previous work (Stibrany et al., 2004), except that 10 mmol of 3-chloro-2-cyanobenzene and 40 mmol of ethylenediamine were used. Single crystals suitable for X-ray diffraction were obtained by evaporation of an acetonitrile solution at room temperature.

Refinement
The H atom bound to N1 was located in a difference Fourier map and refined freely. Other H atoms were positioned geometrically and refined in a riding model approximation, with C-H = 0.93-0.97 Å, and with U iso (H) = 1.2U eq (C). Fig. 1. The molecular structure of (I) with atom labels and 50% probability ellipsoids for non-H atoms.

Special details
Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment. 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.