Crystal structures of 2,6-di-bromo-4-methyl-benzo-nitrile and 2,6-di-bromo-4-methyl-phenyl isocyanide

Wayland E Noland; Jessica E Shudy; Janel L Rieger; Zoe H Tu; Kenneth J Tritch

doi:10.1107/S2056989017016395

Crystal structures of 2,6-di-bromo-4-methyl-benzo-nitrile and 2,6-di-bromo-4-methyl-phenyl isocyanide

Acta Crystallogr E Crystallogr Commun. 2017 Nov 21;73(Pt 12):1913-1916. doi: 10.1107/S2056989017016395. eCollection 2017 Dec 1.

Authors

Wayland E Noland¹, Jessica E Shudy¹, Janel L Rieger¹, Zoe H Tu¹, Kenneth J Tritch¹

Affiliation

¹ Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455, USA.

Abstract

In the title crystals, C₈H₅Br₂N, which are isomorphous, the steric bulk of the methyl group causes neighboring mol-ecules to become mutually inclined. This prevents the formation of planar or nearly planar sheets, which were observed in the tri-chloro and tri-bromo analogs. Instead of CN/NC⋯Br contacts, tetra-meric Br⋯Br contacts are observed. These contacts form tetra-gonally puckered sheets parallel to (001). The CN/NC and methyl groups are grouped at the peaks and troughs. Both mol-ecules lie across crystallographic mirror planes; thus, the methyl H atoms are disordered over two sets of sites with equal occupancy. The title nitrile is a redetermination. The refinement converged at R[F² > 2σ(F²)] = 0.020, whereas the original determination [Gleason & Britton, (1976 ▸). Cryst. Struct. Commun.5, 229-232] had R = 0.112.

Keywords: Br⋯Br contacts; crystal structure; isocyanide; nitrile.