Redetermination of 2-methyl-4-nitropyridineN-oxide

Abstract

An improved crystal structure of the title compound, C6H6N2O3, is reported. The structure, previously solved [Liet al.(1987).Jiegou Huaxue (Chin. J. Struct. Chem.),6, 20–24] in the orthorhombic space groupPca21and refined toR= 0.067, has been solved in the orthorhombic space groupPbcmwith data of enhanced quality, giving an improved structure (R= 0.0485). The molecule adopts a planar conformation with all atoms lying on a mirror plane. The crystal structure is composed of molecular sheets extending parallel to theabplane and connectedviaC—H...O contacts involving ring H atoms and O atoms of theN-oxide and nitro groups, while van der Waals forces consolidate the stacking of the layers.