4-Bromo-2-[(E)-(2-fluoro-5-nitrophenyl)iminomethyl]phenol

The molecular conformation of the title compound, C13H8BrFN2O3, is essentially planar, with maximum deviations of 0.076 (1) and −0.080 (2) Å for the O atoms of the NO2 group. The molecular conformation is stabilized by an intramolecular O—H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, pairs of molecules are linked via two pairs of C—H⋯O hydrogen bonds, forming inversion dimers that enclose R 2 2(7)R 2 2(10)R 2 2(7) ring motifs.

The molecular conformation of the title compound, C 13 H 8 BrFN 2 O 3 , is essentially planar, with maximum deviations of 0.076 (1) and À0.080 (2) Å for the O atoms of the NO 2 group. The molecular conformation is stabilized by an intramolecular O-HÁ Á ÁN hydrogen bond, forming an S(6) ring motif. In the crystal, pairs of molecules are linked via two pairs of C-HÁ Á ÁO hydrogen bonds, forming inversion dimers that enclose R 2 2 (7)R 2 2 (10)R 2 2 (7) ring motifs.

Marzouk Comment
Schiff bases have been shown to exhibit a broad range of biological activities, including antifungal, antibacterial, antimalarial, antiproliferative, anti-inflammatory, antiviral, and antipyretic properties (Przybylski et al., 2009;Kalaivani et al., 2012). Among such compounds, the fluorinated Schiff's bases were considered to possess a distingushed biological activity due to the dramatic affect of fluorine atom on the metabolism and distribution of drug molecules in the body (Blair et al., 2000). Further to our on going study on synthesis of bioactive fluorinated compounds (Mohamed et al., 2012) we herein report the synthesis and crystal structure of a new fluorinated azomethine derivative.

Experimental
A mixture of 1 mmol (156 mg) 2-fluoro-5-nitroaniline and 1 mmol (201 mg) 5-bromo-2-hydroxybenzaldehyde in 50 ml e thanol was heated at 350 K and monitored by TLC till completion after 12 h. A mass solid product was deposited once the reaction mixture was allowed to cool at room temperature. The crude product was filtered dried under vacuum and washed by ethanol. Pure yellow rods (m.p. 465 K) suitable for X-ray diffraction were obtained in an excellent yield (92%) by crystallization of crude product from ethanol.

Refinement
H atoms were positioned geometrically and refined using a riding model, with O-H = 0.84 Å, C-H = 0.95 Å, and with U iso (H) = 1.5U eq (O) for hydroxyl and U iso (H) = 1.2 U eq (C) for the other H atoms.

Figure 2
Crystal packing of (I) viewed along the a axis. The hydrogen atoms not involved in the hydrogen bonds have been omitted for clarity. Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq  (2)