2-[(E)-(4-Bromophenyl)iminomethyl]-4-chlorophenol

In the title compound, C13H9BrClNO, the dihedral angle between the substituted benzene rings is 44.25 (11)°. There are strong intramolecular O—H⋯N hydrogen bonds, which generate S(6) rings, and also intermolecular Cl⋯Cl [3.431 (3) Å] and Br⋯ Br [3.846 (1) Å] contacts. The crystal packing a C—H⋯O and C—H⋯π interactions.


Comment
Schiff bases are condensed by primary amines and carbonyl compounds, containing strong electronegative with atoms O and N, thus it is easy to coordinate with the metal ions to form stable complexes (Akmal et al., 2007;Rehmana et al., 2008). It is reported that metal complexes of Schiff base derivatives have a variety of important biological activities, such as anti-bacterial, anti-cancer, anti-tumor, hypoglycemic and so on (Vanco et al., 2008;Li et al., 2007;Ritter et al., 2009).
Our reports indicated that copper and vanadium complexes of Schiff bases are potential inhitors over protein tyrosine phosphatases Lu et al., 2011;Ma et al., 2011;Yuan et al., 2009Yuan et al., , 2010.
We report here the synthesis and characterization a potentially bidentate Schiff base derivative, (I), and prepared from the condensation reaction of an equimolar proportion of 5-chloro-salicylaldehyde and 4-bromo-aniline in absolute ethanol. The molecular structure is depicted in Fig. 1. X-ray structural analysis confirmed that in the title compound, (I), the dihedral angle between the substituted benzene rings is nearly 44.25 (11)°, similar to the compound 4- (Ardakani et al., 2011). In the crystal, there are strong intramolecular O-H···N hydrogen bonds with a distance of 2.593 (5) Å between donor and acceptor, which generate S(6) ring and intermolecular Cl1···Cl1 i [3.430 (2) Å, i -x, -y, -z] as well as Br1···Br1 ii [3.846 (1) Å, ii 2 -x, -y, -z] contacts. The crystal packing is further stabilized by intermolecular C-H···O and C-H···π interactions (Table 1).

Experimental
A 0.1566 g (1.0 mmol) 5-chloro-salicylaldehyde in 15 ml of absolute ethanol was heated until thoroughly dissolved and 0.1720 g (1.0 mmol) of 4-bromo-aniline in 5 ml of absolute ethanol was added dropwise with a constant stirring. The reaction mixture was heated under refluxing for 3 h. After cooling slowly, the orange powder was separated out. Orangered crystal was obtained from filter after two weeks.

Refinement
H atoms attached to C and O of (I) were placed in geometrically idealized positions with Csp 2 -H = 0.93 Å and O-H = 0.84 Å and constrained to refine with U iso (H) = 1.2U eq (C) and U iso (H) = 1.5U eq (O).

Figure 2
The packing diagram of the title compound, showing the intermolecular O-H···N and intermolecular Cl···Cl, Br···Br and C-H···O interactions (dotted lines). 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.