(E)-3-(2,6-Dichlorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one

In the title compound, C16H12Cl2O2, the dichlorophenyl and methoxyphenyl groups are linked by a prop-2-en-1-one group. The C=C double bond is trans configured. The molecule is not planar, as can be seen from the dihedral angle of 6.21 (7)° between the planes of the two rings. The crystal structure can be described by two types of crossed layers which are parallel to (110) and (10).

In the title compound, C 16 H 12 Cl 2 O 2 , the dichlorophenyl and methoxyphenyl groups are linked by a prop-2-en-1-one group. The C C double bond is trans configured. The molecule is not planar, as can be seen from the dihedral angle of 6.21 (7) between the planes of the two rings. The crystal structure can be described by two types of crossed layers which are parallel to (110) and (110).

Experimental
Chalcone may be useful for the chemotherapy of leishmanisis among others (Lawrence et al., 2001), they are also used as antibiotics (Nielsen et al., 2005). They were synthesized by a base catalyzed Claisen-Schmidt condensation of aromatic aldehydes and ketones. A natural medicine genus Angelica is known to contain large number of naturally occurring chalcones (Sarker et al., 2004). Chalcone derivatives are recognized for NLO properties and have good crystallization ability (Goto et al., 1991;Indira et al., 2002;Sarojini et al., 2006). (Fischer et al., 2007).
The molecular structure of (I), and the atomic numbering used, is illustrated in Fig. 1. A diagram of the layered crystal packing in the unit cell of (I) is shown in Fig. 2. A substituted chalcone adopts an E configuration with respect to the C=C bond of the enone unit. The molecule is not planar, as can be seen from the dihedral angle of 6.21 (7)° between the two rings.
The crystal structure can be described by two types of crossed layers, parallel to (110) and (1-10) respectively (Fig. 2).
The packing is stabilized by Van der Walls interactions and by C-H···π interactions resulting in the formation of three dimensional network (Table 1.).

Experimental
To a mixture of 2,6 dichlorobenzaldehyde (1.75 g, 0.01 mol) and 4-methoxyacetophenone (1.50 g, 0.01 mol) in ethanol 20 ml in the presence of a catalytic amount of sodium hydroxide solution (5 ml) was added slowly with stirring (6 h), the contents of the flask were poured into ice cold water (500 ml) and left to stand for 5 h. The resulting crude solid was filtered and purified by recrystallization in ethanol. Crystal suitable for x-ray analysis was grown by slow evaporation of an acetone solution at room temperature.

Refinement
All H atoms were localized in Fourier maps but introduced in calculated positions and treated as riding on their parent C atoms with C-H = 0.95-0.98Å and U iso (H) =1.2-1.5(carrier atom). Fig. 1. (Farrugia, 1997) The structure of the title compound with the atomic labeling scheme. Displacements are drawn at the 50% probability level.   (10) 0.0030 (7) 0.0014 (7) 0.0009 (7)