Topochemistry. Part XXXIV. Crystal and molecular structure of p′-bromochalcone

Abstract

The crystal structure of p′-bromochalcone has been solved from partial three-dimensional photographic data by the heavy-atom technique, and refined by a least-squares programme to R′ 0·03 and R 0·08. Crystals are monoclinic, space group P2₁/c with Z= 8 in a unit cell of dimensions: a= 15·10(1), b= 5·90(1), c= 31·13(2)Å, β= 108·6(1)°.

Bond lengths and angles in the two molecules of the asymmetric unit, which agree within their estimated standard deviations of 0·02 Å and 1·0°, are similar to those observed in other chalcones. Both molecules are non-planar, the angles between the planes of the two phenyl groups being 50°.

The molecules pack in stacks along [010] with the bromine atoms spiralling along the 2₁ axes.