Crystal Structure and Quadrupole Coupling of Cyanogen Bromide, BrCN

The crystal structure of BrCN has been determined from single-crystal x-ray data. BrCN belongs to space group D2h(13) — Pnmm, with two molecules in a unit cell of dimensions: a=5.80, b=6.02, c=4.12 A (all ±0.03 A). All atoms are in positions 2(a): ±(x, ¼, ¼) with parameters xbr=0.144, xC=0.45, and xN=0.65. The structure is made up of straight chains of BrCN molecules directed along the a-axis with the bromine atom of one molecule bonding weakly to the nitrogen of the next molecule in the same chain. The structure is consistent with recent measurements of quadrupole coupling for the Br and N nuclei.