Crystal structure and DFT study of (E)-2-chloro-4-{[2-(2,4-di-nitro-phen-yl)hydrazin-1-yl-idene]meth-yl}phenol aceto-nitrile hemisolvate.

The title Schiff base compound, C13H9ClN4O5·0.5CH3CN, crystallizes as an aceto-nitrile hemisolvate; the solvent mol-ecule being located on a twofold rotation axis. The mol-ecule is nearly planar, with a dihedral angle between the two benzene rings of 3.7 (2)°. The configuration about the C=N bond is E, and there is an intra-molecular N-H⋯Onitro hydrogen bond present forming an S(6) ring motif. In the crystal, mol-ecules are linked by O-H⋯O and N-H⋯O hydrogen bonds, forming layers lying parallel to (10). The layers are linked by C-H⋯Cl hydrogen bonds, forming a supra-molecular framework. Within the framework there are offset π-π stacking inter-actions [inter-centroid distance = 3.833 (2) Å] present involving inversion-related mol-ecules. The DFT study shows that the HOMO and LUMO are localized in the plane extending from the phenol ring to the 2,4-di-nitro-benzene ring, and the HOMO-LUMO gap is found to be 0.13061 a.u.