2-(5-Chloro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide

The title molecule, C9H7ClN4OS, is almost planar, with an r.m.s. deviation of 0.034 (2) Å for the mean plane through all the non-H atoms. Intramolecular N—H⋯O and N—H⋯N hydrogen bonds form S(6) and S(5) ring motifs, respectively. In the crystal, molecules are assembled into inversion dimers through pairs of co-operative N—H⋯Cl interactions. These dimers are connected along the b axis by N—H⋯O and N—H⋯S hydrogen bonds, generating layers parallel to (103). The layers are further connected along the a axis into a three-dimensional network, through weak π–π stacking interactions [centroid–centroid distance = 3.849 (2) Å].


Synthesis and crystallization
Experimental procedures for synthesis were based on Qasem Ali et al. (2011). Thiosemicarbazide (0.25 g, 2.7 mmol) was mixed to 20 ml of an ethanolic solution containing 5-chloroisatin (0.50 g, 2.7 mmol), followed by addition of ten drops of glacial acetic acid. This mixture was maintained under reflux for 4 h, being a yellow precipitated obtained. The product was filtered off under vacuum, yielding 0.38 g (76.2%). Yellow single crystals suitable for X-ray diffraction measurements were grown in ethanol/acetonitrile (1:1), adding five drops of pyridine and slow evaporating at room temperature.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 1. H-atoms attached to aromatic C atoms were positioned with idealized geometry and were refined isotropic with U eq (H) set to 1.2 times of the U eq (C) using a riding model with C-H = 0.95 Å. H-atoms attached to N atoms were located in difference Fourier maps. Their coordinates and isotropic displacement parameters were refined.

Results and discussion
Isatin and its derivatives are known for demonstrate biological effects, such as bactericide and fungicide activities (Cerchiaro & Ferreira, 2006). This class of compounds has been characterized through X-ray crystallography: (Ali et al., 2012;de Oliveira et al., 2012;Bandeira et al., 2013). As part of our research, in this paper we describe the synthesis (Qasem Ali et al., 2011) and present the crystal structure determination of 1-(5-Chloro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide.
The molecular structure of the title compound, C 9 H 7 ClN 4 OS, shows an E conformation about the N2-N3 bond, matching its asymmetric unit (Fig. 1). The molecule is almost planar (Bandeira et al., 2013), with a r.m.s. deviation of 0.034 Å and maximum deviation from the mean plane through non-H atoms observed for the N1 atom (0.0920 (12) Å).

Computing details
Symmetry codes: (iv) x + 1/2, -y + 3/2, z + 1/2; (v) x -1/2, -y + 3/2, z + 1/2. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Cl1 1.30216 (7