Four nitrobenzaldehyde isonicotinoylhydrazones at 120 K: four different supramolecular structures in two and three dimensions

The molecules of 2-nitrobenzaldehyde isonicotinoylhydrazone, C13H10N4O3, (I), are linked into a three-dimensional framework by a combination of one N - H center dot center dot center dot N and three C-H center dot center dot center dot O hydrogen bonds. In the isomeric compound 3-nitrobenzaldehyde isonicotinoylhydrazone, (II), the molecules are linked into complex sheets by a combination of three hydrogen bonds, one each of the N - H center dot center dot center dot N, C - H center dot center dot center dot N and C - H center dot center dot center dot O types. The molecules of the third isomer, namely 4-nitrobenzaldehyde isonicotinoylhydrazone, (III), are linked into bilayers by a combination of one N - H center dot center dot center dot N, one C-H center dot center dot center dot N and two C - H center dot center dot center dot O hydrogen bonds. 2,4-Dinitrobenzaldehyde isonicotinoylhydrazone, (IV), crystallizes as a stoichiometric monohydrate, C(13)H(9)N(5)O(5)center dot H2O, and the molecular components are linked into a three-dimensional framework by a combination of O - H center dot center dot center dot O, O - H center dot center dot center dot N, N-H center dot center dot center dot O and three independent C - H center dot center dot center dot O hydrogen bonds.