Dimorphic forms of 3,6-dinitrodurene in a single space group.
3,6-Dinitrodurene (1,2,4,5-tetramethyl-3,6-dinitrobenzene), C(10)H(12)N(2)O(4), 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 C(ipso) 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.
Facultad de Ingeniería Química, BUAP, 14 sur y San Claudio, Ciudad Universitaria, 72000 Puebla, Pue., Mexico.
José Alberto
JA
Galicia Aguilar
Sylvain
S
Bernès