N′-[(E)-2-Chloro-5-nitrobenzylidene]-2-nitrobenzohydrazide

In the title compound, C14H9ClN4O5, the molecule exists in a trans geometry with respect to the methylidene unit. The dihedral angle between the two substituted benzene rings is 62.7 (2)°. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) loops.

In the title compound, C 14 H 9 ClN 4 O 5 , the molecule exists in a trans geometry with respect to the methylidene unit. The dihedral angle between the two substituted benzene rings is 62.7 (2) . In the crystal, inversion dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds generate R 2 2 (8) loops.   Table 1 Hydrogen-bond geometry (Å , ).
In the title compound ( Fig. 1), the hydrazone molecule exists in a trans geometry with respect to the methylidene unit.
Experimental 2-Chloro-5-nitrobenzaldehyde (1.0 mmol, 185 mg) and 2-nitrobenzohydrazide (1.0 mmol, 181 mg) were mixed in 50 mL methanol. The mixture was stirred at ambient temperature for 2 h and filtered. Colorless blocks of (I) were formed by slow evaporation of the filtrate for 5 d.

Refinement
The amino hydrogen atom was located in an electronic density map and refined isotropically, with the N-H distance restrained to 0.90 (1)Å. Other hydrogen atoms were placed in calculated positions, with C-H = 0.93 Å, and refined as riding with U iso (H) = 1.2U eq (C). The structure contains solvent accessible VOIDS of 70 Å 3 , which might accord a disordered water molecule. Fig. 1. Molecular structure of (I) with 30% probability displacement ellipsoids. supplementary materials sup-2

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds supplementary materials sup-3 in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.