Tetrazole studies. Part II. Crystal structure of 5-bromotetrazole

Abstract

The structure of the title compound has been established by X-ray crystallography from diffractometer data. Crystals are monoclinic, space group P2₁/m, cell dimensions a= 4·935(5), b= 6·279(5), c= 7·446(5), β= 116·8(±0·2). 316 Statistically reliable reflections were refined to R 0·045. Within the limits of experimental error the molecule appears to possess m-symmetry. Ring bond distances are: C–N 1·290 and 1·351, N–N 1·283–1·347 Å. The ring hydrogen could not be located, nor were hydrogen positions indicated by short N ⋯ N intermolecular contacts or approximately tetrahedral angles at the corresponding nitrogens. Ring distances clearly indicate the tetrazole ring to be a resonance hybrid. The planar molecules form sheets stacked along the b axis with a perpendicular spacing of ½b(3·14 Å). Data were also refined in space group P2₁ to R 0·044 and the resulting model did not vary significantly from that obtained using space group P2₁/m.