2-Bromo-4-chloro-6-(cyclopentyliminomethyl)phenol

All atoms of the title molecule, C12H13BrClNO, except the C and H atoms of the cyclopentane methylene groups lie on a crystallographic mirror plane. The cyclopentane ring adopts an envelope conformation and an intramolecular O—H⋯N hydrogen bond is observed. In the crystal, molecules are stacked along the b axis by π–π interactions [centroid–centroid distance = 3.6424 (11) Å].


D-HÁ
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CI2924).  (Dao et al., 2000;Sriram et al., 2006;Karthikeyan et al., 2006). Schiff bases have also been used as versatile ligands in coordination chemistry (Ali et al., 2008;Kargar et al., 2009;Yeap et al., 2009). Recently, crystal structures of a large number of Schiff base compounds have been reported Nadeem et al., 2009;Eltayeb et al., 2008). In this paper, the title new Schiff base compound ( Fig. 1) is reported.

Structure Reports Online
All atoms of the title molecule, except the C and H atoms of the four methylene groups lie on a crystallographic mirror plane. The cyclopentane ring adopts a an envelope conformation. An intramolecular O-H···N hydrogen bond (Table 1) is observed. All bond lengths are within normal values (Allen et al., 1987).
Experimental 3-Bromo-5-chlorosalicylaldehyde (0.1 mmol, 23.5 mg) and cyclopentylamine (0.1 mmol, 8.5 mg) were refluxed in a 30 ml methanol solution for 30 min to give a clear orange solution. Yellow block-shaped single crystals of the title compound were formed by slow evaporation of the solvent over several days at room temperature.

Refinement
Atom H1 was located from a difference map and its positional parameters were refined. The remaining H atoms were constrained to ideal geometries, with C-H = 0.93-0.98 Å. The U iso (H) values were set at 1.2U eq (C) and 1.5U eq (O). The U ij components of atom C10 were restrained to an approximate isotropic behaviour. Fig. 1

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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.