4-Methylbenzenecarbothioamide

In the title molecule, C8H9NS, the mean plane of the carbothioamide group is twisted slightly with respect to the mean plane of the benzene ring, making a dihedral angle of 17.03 (10)°. The crystal structure is stabilized by intermolecular N—H⋯S hydrogen bonds, resulting in the formation of eight-membered rings lying about inversion centers and representing R 2 2(8) and R 4 2(8) motifs. Futhermore, these hydrogen bonds build up chains parallel to the b axis.

In the title molecule, C 8 H 9 NS, the mean plane of the carbothioamide group is twisted slightly with respect to the mean plane of the benzene ring, making a dihedral angle of 17.03 (10) . The crystal structure is stabilized by intermolecular N-HÁ Á ÁS hydrogen bonds, resulting in the formation of eight-membered rings lying about inversion centers and representing R 2 2 (8) and R 4 2 (8) motifs. Futhermore, these hydrogen bonds build up chains parallel to the b axis.

Experimental
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2557).

Comment
Thioamides are not only used as intermediates in the synthesis of various heterocyclic compounds (Zahid et al., 2009), they are important biologically active agents (Jagodzinski, 2003;Klimesova et al., 1999). In addition, they are important ligands in the field of coordination chemistry (Lebana et al., 2008). In continuation to our work on thioamides (Khan et al., 2009a;2009b;2009c;Ali et al., 2010), we have synthesized 4-methylbenzenecarbothioamide, (I). In this article we report the crystal structure of the title compound.
In the title molecule ( Fig. 1), the bond distances and angles agree with the corresponding bond distances and angles reported in closely related compounds (Khan et al., 2009a;2009b;2009c;Jian et al., 2006;Ali et al., 2010). In the title compound, the mean-plane of the carbothioamide group (S1/N1/C7) is slightly twisted with respect to the mean-plane of the phenyl ring (C1-C6), making a dihedral angle of 17.03 (10)°.
The structure is stabilized by intermolecular N-H···S hydrogen bonds resulting in the formation of eight membered rings lying about inversion centers (Tab. 1 and Fig. 2). In the graph set notation (Etter et al., 1990;Bernstein et al., 1994) the hydrogen bonded rings may be best described as representing R 2 2 (8) and R 4 2 (8) motifs.Futhermore, these hydrogen bonds build up chains parallel to the b axis.
Experimental 4-Methylbenzonitrile (13.2 mmol) was added to a slurry of magnesium cholride hexahydrate (13.2 mmol) and sodium hydrogen sulphide hydrate (70%, 26.4 mmol) in dimethylformamide (35 ml) and the reaction mixture was stirred at room temperature for 4 h. The reaction mixture was poured into water (100 ml) and the resulting precipitates were collected by filtration. The product obtained was resuspended in 1 N HCl (50 ml), stirred for another 25 min, the precipitated solid filtered and washed with water. Recrystallization of the product from chloroform afforded the crystals of the title compound suitable for X-ray analysis.

Refinement
Though all the H atoms could be distinguished in the difference Fourier map the H-atoms were included at geometrically

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.