Methyl 2-methoxy-4-{[2-(4-nitrophenyl)hydrazinylidene]methyl}benzoate

The molecule of the title Schiff base compound, C16H15N3O5, obtained from a condensation reaction of 4-acetoxy-3-methoxybenzaldehyde and 4-nitrophenylhydrazine, adopts an E geometry with respect to the C=N double bond. The molecule is roughly planar, with the two benzene rings twisted slightly with respect to each other by a dihedral angle of 6.90 (9)°. In the crystal, intermolecular N—H⋯O hydrogen bonds link centrosymmetrically related pairs of molecules, forming dimers of R 2 2(22) graph-set motif. The dimers are further connected through slipped π–π interactions between symmetry-related benzene rings [centroid–centroid distance of 3.646 (1) Å, offset angle of 15.4°].

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2604).

Comment
As some phenylhydrazone derivatives show potential application in biochemistry (Okabe et al.,1993), phenylhydrazone has recently attracted our attention. In this paper, we report the synthesis and crystal structure of the title compound.
The molecule adopts an E geometry with respect to the C=N double bond (Fig. 1). The methoxybenzene and the nitrobenzene rings are roughly planar, with however the two benzene rings slightly twisted with respect to each other by a dihedral angle of 6.90 (9)°. The geometry within the hydrazone moiety agrees with related compound found in the literature (Szczesna & Urbanczyk-Lipkowska, 2002;Zhen & Han, 2005;Kuleshova et al., 2003;Baughman et al., 2004. Intermolecular N-H···O hydrogen bonds link the molecule two by two to form dimer (Table 1, Fig. 2) with R 2 2 (22) graph set motif (Etter et al., 1990); Bernstein et al., 1994). The dimers are connected through slippest π-π interactions involving the symmetry related (1-x, -y, -z) C1-C6 and C8-C13 benzene rings with a centroid to centroid distance of 3.646 (1)Å and an interplanar distance of 3.515Å resulting in an offset angle of 15.4°.

Refinement
All H atoms attached to C atoms and N atom were fixed geometrically and treated as riding with C-H = 0.96 Å (methyl) or 0.93 Å (aromatic) and N-H = 0.86 Å with U iso (H) = 1.2U eq (C or N) or U iso (H) = 1.5U eq (C methyl ).

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.