Crystal structure of (E)-N′-benzylidene-1-methyl-4-nitro-1H-pyrrole-2-carbohydrazide

In the title compound, C13H12N4O3, the dihedral angle between the planes of the pyrrole and benzene rings is 7.47 (1)°. In the crystal, molecules are arranged in sheets lying parallel to (101). Neighbouring sheets are linked by N—H⋯O hydrogen bonds, weak π–π [centroid–centroid distance between the pyrrole rings = 3.765 (11) Å] and C—H⋯π interactions, forming a three-dimensional structure.


D-HÁ
Hydrazones and analogous compounds have attracted attention from researchers due to their well known chelating capability and structural flexibility (Krishnamoorthy, et al., 2012;Raja, et al., 2012). In our lab, a series of asymmetric Nheterocyclic substituted hydrazones and their metal complexes were obtained and characterized (Wang et al., 2011). The interactions of these compounds with CT-DNA and pBR322 DNA has been explored (Wang et al., 2014). The present work is an extension of our earlier studies.
In the title compound ( Fig. 1) the phenyl and pyrrolyl ring are linked by an acyl-hydrazone moiety. The dihedral angle between the phenyl and pyrrolyl rings is 7.47 (1)°.
As shown in Figure 2, molecules of the title compound form sheet parallel to the (101) plane.
The neighbouring sheets are linked by N-H···O hydrogen bonds, weak π···π interactions between pyrrolyl rings and C-H···π interactions ( Figure 3). These interactions result in the formation of a three-dimensional network (Fig. 4).

S3. Refinement
H atoms were placed in geometrically idealized positions, with N-H=0.86 Å, C aromatic -H=0.93, C methyl -H 0.96 Å, and with  The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are represented as small spheres of arbitrary radius.

Figure 2
Molecules of the title compound forming planes parallel to the (101)  The intermolecular N-H···O hydrogen bonds (black dotted lines), π···π and C-H···π interactions (pink dotted lines) between adjacent sheets (H atoms not involved in hydrogen bonds have been omitted for clarity, all distances in Å).

Figure 4
Packing of the title compound viewed along the b axis.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 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.