A triclinic polymorph of (E)-2-(4-iso­butyl­phen­yl)-N′-[1-(4-nitro­phen­yl)ethyl­idene]propano­hydrazide

The asymmetric unit of the triclinic polymorph of the title compound, C₂₁H₂₅N₃O₃, consists of two mol­ecules, whereas for the monoclinic polymorph Z′ = 1 [Fun et al. (2009). Acta Cryst. E65, o445]. The two mol­ecules exhibit an E configuration with respect to the C=N bond. The mol­ecules are linked into dimers by N—H...O and C—H...O hydrogen bonds forming R₂²(8) ring motifs. In addition, π–π inter­actions occur between nitro­phenyl groups [minimum centroid–centroid distance 3.940 (2) Å], stacking the molecules along the ac plane.