(2E)-1-(2-Bromophenyl)-3-(4-chlorophenyl)prop-2-en-1-one

In the title compound, C15H10BrClO, the dihedral angle between the mean planes of the benzene rings in the ortho-bromo- and para-chloro-substituted rings is 70.5 (6)°. The dihedral angles between the mean plane of the prop-2-en-1-one group and the mean planes of the benzene rings in the 4-chlorophenyl and 2-bromophenyl rings are 14.9 (3) and 63.3 (8)°, respectively. In the crystal, inversion dimers linked by pairs of weak C—H⋯O interactions are observed as well as aromatic π–π stacking interactions.

In the title compound, C 15 H 10 BrClO, the dihedral angle between the mean planes of the benzene rings in the orthobromo-and para-chloro-substituted rings is 70.5 (6) . The dihedral angles between the mean plane of the prop-2-en-1one group and the mean planes of the benzene rings in the 4chlorophenyl and 2-bromophenyl rings are 14.9 (3) and 63.3 (8) , respectively. In the crystal, inversion dimers linked by pairs of weak C-HÁ Á ÁO interactions are observed as well as aromaticstacking interactions.
occurring chalcones are polyhydroxylated in the aryl rings. The radical quenching properties of the phenol groups present in many chalcones have raised interest in using the compounds or chalcone rich plant extracts as drugs or food preservatives (Dhar, 1981). Chalcones have been reported to possess many useful properties, including anti-inflammatory, antimicrobial, antifungal, antioxidant, cytotoxic, anticancer activities (Dimmock et al., 1999). Many chalcones have been described for their high antimalarial activity, probably as a result of Michael addition of nucleophilic species to the double bond of the enone (Troeberg et al., 2000). Chalcones are finding applications as organic non-linear optical materials (NLO) due to their good SHG conversion efficiencies (Sarojini et al., 2006). Hence, in continuation with our synthesis and crystal structure determinations of similar compounds (Jasinski et al., 2009;Jasinski et al., 2010) and also owing to the importance of these flavanoid analogs, this new bromo-chloro substituted chalcone, C 15 H 10 BrClO, is synthesized and its crystal structure is reported.

Experimental
A 50% KOH solution was added to a mixture of 2-bromo acetophenone (0.01 mol, 1.99 g) and 4-chloro benzaldehyde (0.01 mol, 1.40 g) in 25 ml of ethanol (Fig. 1). The mixture was stirred for an hour at room temperature and the precipitate was collected by filtration and purified by recrystallization from ethanol. The single-crystal was grown from ethyl acetate by slow evaporation and the yield of the compound was 58% (m.p.368-370 K). Analytical data: Composition (%) found (Calculated): C: 55.97 (56.02); H: 3.09(3.13).

Refinement
The H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C-H distances = 0.95Å and with U iso (H) = 1.18-1.22 U eq (C). Fig. 1. Reaction Scheme for the title compound.    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.

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