Acta Cryst. (2013). E69, o152
[ doi:10.1107/S1600536812051288 ]
Abstract: The title compound, C12H7N5O8, was previously described in space group P21/n with Z = 4 [Wu et al. (2007). Acta Cryst. E63, o4194]. The current monoclinic P21/c polymorph was obtained from a mixed solution of dichloromethane and hexane. The dihedral angle between the benzene rings is 44.16 (5)°, smaller than in the previously reported polymorph [56.3 (2)°]. As a result of the steric hinderance of the nitro groups, hydrogen bonding is limited intramolecularly. The dihedral angles between the phenyl rings and their attached nitro groups are 18.97 (6) and 17.71 (5)° at the 2-position, and 18.52 (6) and 32.41 (6)° at the 4-position.
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