Synthesis and structure of alpha,beta-dibromo-beta-nitrostyrenes

A procedure was developed for preparing a new type of halonitroethenes, 1,2 -dibromo-1-nitro-2-phenyl- and -2-(p-chlorophenyl)ethenes; the energies and geometries of their molecules were calculated. The bond lengths, bond angl es, and torsion angles in the former molecule were determined by single cry stal X-ray diffraction. The molecule has the E configuration; the benzene r ing is turned relative to the plane formed by the double bond and the bromi ne atoms and randomly occupies two preferable positions.