1-(2-Furylmethylene)-2-(2-nitrophenyl)hydrazine

The title Schiff base compound, C11H9N3O3, was obtained from a condensation reaction of furan-2-carbaldehyde and 2-nitrophenylhydrazine. The molecule is roughly planar, the largest deviation from the mean plane defined by all non-H atoms being 0.097 (4). An in ntramolecular N—H⋯O hydrogen bond might influence the planar conformation of the molecule. In the crystal, weak C—H⋯O hydrogen bonds link the molecules, forming a chain.

The title Schiff base compound, C 11 H 9 N 3 O 3 , was obtained from a condensation reaction of furan-2-carbaldehyde and 2nitrophenylhydrazine. The molecule is roughly planar, the largest deviation from the mean plane defined by all non-H atoms being 0.097 (4). An in ntramolecular N-HÁ Á ÁO hydrogen bond might influence the planar conformation of the molecule. In the crystal, weak C-HÁ Á ÁO hydrogen bonds link the molecules, forming a chain.

Comment
The chemistry of Schiff base has attracted a great deal of interest in recent years. These compounds play an important role in the development of various proteins and enzymes (Kahwa et al., 1986;Santos et al., 2001). As part of our interest in the study of the coordination chemistry of Schiff bases, we synthesized the title compound and determined its crystal structure.
The whole molecule is roughly planar with the largest deviations from the mean plane being -0.0973 (0.0041) at O3 (Fig.  1). The phenyl and the furan rings are slightly twisted from each other making a dihedral angle of 4.8 (3)°.
The intramolecular N-H···O hydrogen bond might influence the planar conformation of the molecule. Weak intermolecular C-H···O hydrogen bonds link the molecule forming a chain parallel to the (1 0 1) plane (Table 1, Fig. 2).
Experimental 2-Nitrophenylhydrazine (1 mmol, 0.153 g) was dissolved in anhydrous ethanol (15 ml), The mixture was stirred for several minitutes at 351k, furan-2-carbaldehyde (1 mmol, 0.096 g) in ethanol (8 mm l) was added dropwise and the mixture was stirred at refluxing temperature for 2 h. The product was isolated and recrystallized from methanol, red single crystals of (I) was obtained after 3 d.

Refinement
All H atoms were positioned geometrically and refined as riding with C-H=0.93 (aromatic), N-H=0.86 Å, and U iso (H)=1.2U eq (C). Fig. 1. Molecular view of (I) with the atom labeling scheme. Displacement ellipsoids are drawn at the 30% probability level. Hydrogen are represented as small sphere of arbitrary radii. Intramolecular N-H···O hydrogen bond is shown as dashed lines.

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 > 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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )