In the title crystals, C 8 H 5 Br 2 N, 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/NCBr contacts, tetrameric BrBr 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. The title nitrile is a redetermination. The refinement converged at R[F 2 > 2σ(F 2)] = 0.020, whereas the original determination [Gleason & Britton, (1976). Cryst. Struct. Commun. 5, 229-232] had R = 0.112.
|Original language||English (US)|
|Number of pages||4|
|Journal||Acta Crystallographica Section E: Crystallographic Communications|
|State||Published - 2017|
Bibliographical noteFunding Information:
The authors thank Victor G. Young, Jr. (X-Ray Crystallographic Laboratory, University of Minnesota) for assistance with the crystallographic determination, the Wayland E. Noland Research Fellowship Fund at the University of Minnesota Foundation for generous financial support of this project, and Doyle Britton (deceased July 7, 2015) for providing the basis of this project. This work was taken in large part from the PhD thesis of KJT (Tritch, 2017).
- BrBr contacts
- crystal structure