Crystal structure and Hirshfeld surface analysis of a conformationally unsymmetrical bischalcone: (1 E,4 E)-1,5-bis(4-bromophenyl)penta-1,4-dien-3-one

Abstract

In the title bischalcone, C17H12Br2O, the olefinic double bonds are almost coplanar with their attached 4-bromophenyl rings [torsion angles = -10.2 (4) and -6.2 (4)°], while the carbonyl double bond is in an s-trans conformation with with respect to one of the C=C bonds and an s-cis conformation with respect to the other [C=C - C=O = 160.7 (3) and -15.2 (4)°, respectively]. The dihedral angle between the 4-bromophenyl rings is 51.56 (2)°. In the crystal, molecules are linked into a zigzag chain propagating along [001] by weak C - H...π interactions. The conformations of related bischalcones are surveyed and a Hirshfeld surface analysis is used to investigate and quantify the intermolecular contacts.