3,4-Bis(4-nitrophenyl)-1,2,5-oxadiazole 2-oxide

Abstract

The title compound, C14H8N4O6, a new 1,2,5-oxadiazole N-oxide derivative, was formed by dimerization of 4-nitrobenzaldehyde oxime. The compound crystallizes with two independent molecules per asymmetric unit. The N-oxide O atom is disordered over two sites in each molecule; site occupancy factors are 0.57/0.43 and 0.5/0.5. The mean planes through the two benzene rings are inclined to the planar 1,2,3-oxadiazole ring by 25.03 (11) and 41.64 (11)° in one molecule, and 22.58 (11) and 42.66 (11)° in the other molecule, the smaller angle being for the ring on the oxide side of the oxadiazole ring in each case. In the crystal structure, the individual molecules form centrosymmetric dimers linked via C—H...O hydrogen bonds. The dimers of one molecule are then linked to those of the other molecule via C—H...O hydrogen bonds, forming a three-dimensional network.