Crystal and molecular structure of the N-oxide of 3,4-(p-chlorobenzoyl)-1,2,5-oxadiazole

Abstract

The N-oxide of 3,4-(p-chlorobenzoyl)-1,2,5-oxadiazole, one of the two isomers obtained by reaction of p-chloroacetophenone with nitric acid, crystallizes in the monoclinic system, space group P2₁/c, with Z= 4 in a unit cell with dimensions a₀= 10·632, b₀= 23·823, c₀= 6·175 Å, β= 95° 20′. A crystal structure analysis has been made using three-dimensional data collected with an automatic diffractometer. The molecule, as a whole, is not planar, whereas each of the three moieties is. The shortest intermolecular contacts are between the extranuclear oxygen atom of one molecule and the atoms of the furoxan ring of a neighbouring molecule.