(E)-1-(2,4-Dinitrophenyl)-2-(2-fluorobenzylidene)hydrazine

In the title compound, C13H9FN4O4, the dihedral angle between the mean planes of the two benzene rings of the nearly planar molecule is 6.6 (9)°. The dihedral angles between the mean planes of the benzene ring and its two attached nitro groups are 6.7 (7) and 7.2 (9)°. Crystal packing is stabilized by N—H⋯O hydrogen bonds, weak C—H⋯O and C—H⋯F intermolecular interactions and centroid–centroid π-ring stacking interactions.

In the title compound, C 13 H 9 FN 4 O 4 , the dihedral angle between the mean planes of the two benzene rings of the nearly planar molecule is 6.6 (9) . The dihedral angles between the mean planes of the benzene ring and its two attached nitro groups are 6.7 (7) and 7.2 (9) . Crystal packing is stabilized by N-HÁ Á ÁO hydrogen bonds, weak C-HÁ Á ÁO and C-HÁ Á ÁF intermolecular interactions and centroidcentroid -ring stacking interactions.
In the title compound the dihedral angle between the mean planes of the two benzene rings of a nearly planar molecule is 6.69°, (Fig. 2). The dihedral angle between the mean planes of the benzene ring and its two bonded nitro groups are 6.7 (7)°a nd 7.2 (9)°, respectively. Crystal packing is stabilized by N-H···O hydrogen bonds (Fig. 3), weak C-H···O intermolecular interactions and Cg-Cg π-ring stacking interactions (Table 2).

Experimental
A mixture of 2,4-dinitrophenylhydrazine (1.98 g) and 2-fluorobenzaldehyde (1.24 g) was dissolved in methanol and refluxed for about 6h. The precipitate formed was filtered, dried and recrystallized in ethlyacetate. X-ray quality crystals of the title compound (I), were obtained after three days by the slow evaporation of a 1:1 mixture of dimethylformamide and pyridine at room temperature. (mp: 502 -505 K).

Refinement
The parameters of all the H atoms have been constrained within the riding atom approximation. C-H bond lengths were constrained to 0.95 Å for aryl atoms, U iso (H) = 1.18-1.20U eq (C aryl ). N-H bond lengths were constrained to 0.88 Å, U iso (H) = 1.20U eq (N). Fig. 1. Molecular structure of the title compound showing the atom labeling scheme and 50% probability displacement ellipsoids.

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 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 > σ(F 2 ) is used only for calculating Rfactors(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.