2-Amino-5-nitro-N-[(E)-thiophen-2-ylmethylidene]aniline

In the title molecule, C11H9N3O2S, the thiophene and benzene rings form a dihedral angle of 17.68 (9)°. The thiophene S atom and the imine N atom are syn with respect to each other. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds connect molecules, forming a two-dimensional network parallel to (10-1).

In the title molecule, C 11 H 9 N 3 O 2 S, the thiophene and benzene rings form a dihedral angle of 17.68 (9) . The thiophene S atom and the imine N atom are syn with respect to each other. In the crystal, N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds connect molecules, forming a two-dimensional network parallel to (101).
The title compound exhibits syn geometry about the imine group. A perspective view of the compound is shown in Figure 1. The thiophene and benzene rings are slightly tilted with an interplanar angle of 17.58 (9)°. The imine group displays a torsional angle (C2-N2-C7-C8) of 178.5 (2)°. The plane of the nitro group is 3.6 (2)° out of the benzene ring mean plane.
A two dimensional hydrogen-bonded network ( Fig. 2) emanating from the amino group and extending to a nitro oxygen atom and an imine nitrogen atom connects symmetry related molecules parallel to (101). Single crystals were obtained via vapor diffusion of hexanes into a concentrated 1-propanol solution of the title compound.

Refinement
The amine hydrogen atoms (HA, HB) and the imine hydrogen atom (H7) were refined isotropically. All other hydrogen atoms were refined using a riding model (AFIX 43). The hydrogen atom thermal parameters were set using the approximation U iso = 1.2U eq (C).

Figure 2
Unit cell packing diagram of the title compound displaying the donor-acceptor distances of the hydrogen-bonding network as dashed lines. H atoms are not shown and displacement ellipsoids are displayed at the 25% probability level.

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.