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

The title compound, C(14)H(12)N(4)O(6)·C(3)H(7)NO, 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 P [Image: see text] (Z = 2), whereas the structure reported here is monoclinic (P2(1) /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°).