A second polymorph of 3,4-bis(6-bromopyridin-3-yl)-1,2,5-thiadiazole

Abstract

The title compound, C12H6Br2N4S, a second polymorph in the triclinic space group P-1, is presented. As in the earlier reported monoclinic polymorph in the space group C2/c [Becker et al. (2016). Chem. Eur. J. In the press], the thiadiazole ring is planar with an r.m.s. deviation of 0.004 Å. The five-membered ring is tilted with respect to the two pyridyl substituents by 23.16 (7) and 49.47 (9)°. In the crystal, molecules are linked by a weak non-bonding Br...N interaction [3.056 (3) Å]. Furthermore, a column of molecules is established along the b axis by π–π stacking interactions between the pyridine rings [centroid–centroid distances = 3.7014 (16) and 3.5934 (15) Å]. Additionally, a short intermolecular Br...Br contact [3.3791 (6) Å] and Br...π-aryl contacts [3.6815 (11)–3.7659 (12) Å] towards the thiadiazole and pyridine rings are found.

Keywords

• crystal structure
• heterocycle
• thiadiazole
• polymorph