Crystal structures of 2,6-dibromo-4-methylbenzo- nitrile and 2,6-dibromo-4-methylphenyl isocyanide

Noland. W. E.; Shudy, J. E.; Rieger. J. L.;Tu. H. Z.;Tritch. K. J. ActaCryst. E. 2017, E73, 1913–1916


In the title crystals, C8H5Br2N, which are isomorphous, the steric bulk of the methyl group causes neighboring molecules to become mutually inclined. This prevents the formation of planar or nearly planar sheets, which were observed in the trichloro and tribromo analogs. Instead of CN/NC....Br contacts, tetrameric Br....Br contacts are observed. These contacts form tetragonally puckered sheets parallel to (001). The CN/NC and methyl groups are grouped at the peaks and troughs. Both molecules lie across crystallographic mirror planes; thus, the methyl H atoms are disordered over two sets of sites with equal occupancy.