(E)-1-(1,3-Benzodioxol-5-yl)-3-(3-bromophenyl)prop-2-en-1-one

In the title compound, C16H11BrO3, the molecules adopt an E configuration with respect to the C=C double bond of the propenone unit. The 13 non-H atoms of the benzodioxole and propenone units are approximately coplanar (r.m.s. deviation = 0.027 Å) and the bromobenzene ring plane forms a dihedral angle of 10.8 (1)° to this plane. The structure is layered, with the molecules forming a herring-bone arrangement within each layer.

In the title compound, C 16 H 11 BrO 3 , the molecules adopt an E configuration with respect to the C C double bond of the propenone unit. The 13 non-H atoms of the benzodioxole and propenone units are approximately coplanar (r.m.s. deviation = 0.027 Å ) and the bromobenzene ring plane forms a dihedral angle of 10.8 (1) to this plane. The structure is layered, with the molecules forming a herring-bone arrangement within each layer.

Experimental
TVS thanks Mangalore University for research facilities.

S1. Comment
Chalcones have been widely used as starting materials in preparation of various molecules including fused heterocyclic compounds (Insuasty et al., 1997). Chalcones are also finding application as organic nonlinear optical (NLO) materials because of their SHG conversion efficiency. The crystal structures of some benzodioxol-and bromo-substituted chalcones have been studied (Butcher et al., 2007a,b,c). In continuation of this theme, and also owing to the general importance of these flavanoid analogues, we report herein the synthesis and crystal structure of a new chalcone, namely

S3. Refinement
H atoms were placed at calculated positions and refined using a riding model, with C-H = 0.93-0.97 Å and U iso (H) = 1.2U eq (C).  (7) 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Br1 0.489230 (17