Low-temperature redetermination of benzofurazan 1-oxide

In the six-membered ring of the low-temperature crystal structure of benzofurazan 1-oxide, C(6)H(4)N(2)O(2), the two C atoms adjacent to the N atoms are linked by a delocalized aromatic bond [1.402 (2) Å]; each is connected to its neighbour by a longer, more localized, bond [1.420 (2), 1.430 (2) Å]. However, the next two bonds in the ring approximate double bonds [1.357 (2), 1.366 (2) Å]. As such, the six-membered ring is better described as a cyclo-hexa-diene system, in contrast to the description in the room-temperature structure reported by Britton & Olson (1979 ▶) [Acta Cryst. B35, 3076-3078].