Dimorphic forms of 3,6-dinitrodurene in a single space group
International Union of Crystallography, 2009
Acta Crystallographica Section C
Volume 65, Issue 4, pages o176–o178, April 2009
How to Cite
Galicia Aguilar, J. A. and Bernès, S. (2009), Dimorphic forms of 3,6-dinitrodurene in a single space group. Acta Crystallographica Section C, 65: o176–o178. doi: 10.1107/S0108270109008439
3,6-Dinitrodurene (1,2,4,5-tetramethyl-3,6-dinitrobenzene), C10H12N2O4, has been crystallized in two polymorphic forms which may be distinguished by their colours in the solid state. Polymorph I gives clear colourless prismatic crystals, while polymorph II crystallizes in the dark and under an inert atmosphere as irregular purple blocks. Both forms belong to the space group C2/c, with both asymmetric units containing two half-molecules. One molecule is located on an inversion centre and the other lies on a twofold axis. The polymorphism arises from different orientations of the twofold axis: in form I, this axis passes through the mid-points of two C—C bonds of the benzene ring and, as a consequence, all atoms in the asymmetric unit are in general positions. In form II, the N atoms of the nitro groups and the Cipso atoms are located on the binary axis. Comparing phases I and II, slightly different conformations are observed for the nitro substituents, while the stacking structures are very similar.