A monoclinic polymorph with Z = 4 of (E)-2,4-dihydroxyacetophenone 2,4-dinitrophenylhydrazone N,N-dimethylformamide monosolvate

The title compound, C14H12N4O6·C3H7NO, is a monoclinic polymorph of an already published structure [Baughman et al. (2004). Acta Cryst. C60, 103–106]. In the previously reported structure, the compound crystallized in the triclinic space group Poverline{1} (Z = 2), whereas the structure reported here is monoclinic (P21/n, Z = 4). In both forms, two intramolecular hydrogen bonds result in the formation of a fairly planar hydrazone skeleton (r.m.s. deviations for all non-H atoms = 0.127 Å for the monoclinic from and 0.131 Å for the triclinic form) and each molecule is hydrogen bonded to one solvent molecule. The principal difference between the two forms lies in the different orientation of the two molecules. In the monoclinic form, the two molecules are almost coplanar [dihedral angle = 3.27 (2)°], whereas in the triclinic form the two molecules are almost mutulally perpendicular (dihedral angle = 85.3°).