2-[(4-Bromophenylimino)methyl]-4,6-diiodophenol

The title compound, C13H8BrI2NO, was prepared by the reaction of 3,5-diiodosalicylaldehyde with 4-bromophenylamine in ethanol. There is an intramolecular O—H⋯N hydrogen bond in the molecule, which generates an S(6) ring. The dihedral angle between the benzene rings is 2.6 (3)°.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: QM2053). Schiff bases have been extensively studied for their biological activities (Chohan et al., 2012;Yan et al., 2011;Zhang et al., 2011). In addition, Schiff bases are versatile ligands for the preparation of metal complexes (You et al., 2008;Xu et al., 2009;Chen et al., 2010;Cui et al., 2011). In the present paper, the new title compound is reported.
The molecule of the compound exists in a trans configuration with respect to the methylidene unit ( Fig. 1). There is an intramolecular O1-H1···N1 hydrogen bond in the molecule ( Table 1). The dihedral angle between the C1-C6 and C8-C13 benzene rings is 2.6 (3)°. The bond distances are within the normal range (Allen et al., 1987).
The mixture was stirred at room temperature for 30 min to give a yellow solution. Yellow block-shaped single crystals were obtained by slow evaporation of the solution in air.

Refinement
H-atoms were positioned geometrically and refined using a riding model, with C-H = 0.93-0.97 Å, O-H = 0.82 Å, and with U iso (H) set to 1.2U eq (C) and 1.5U eq (O).

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 R-factors(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.