Crystal structure of S-hexyl (E)-3-(4-methylbenzylidene)dithiocarbazate

In the title compound, C15H22N2S2, the dithiocarbazate group adopts an E conformation with respect to the C=N bond of the benzylidene moiety. In the crystal, molecules are linked by pairs of N—H⋯S hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif. The dimers are linked via C—H⋯π interactions, forming chains propagating along [100].

Cg1 is the centroid of the C1-C6 ring.

S2. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The H atom of the NH group was located in a difference Fourier map and freely refined. The C-bound H atoms were included in calculated positions and treated as riding atoms: C-H = 0.95-0.99 Å with U iso (H) = 1.5U eq (C) for methy H atoms and = 1.2U eq (C) for other H atoms.

S3. Comment
Bidentate Schiff bases of S-methyl dithiocarbazate or S-benzyl dithiocarbazates and their bivalent metal complexes have received considerable attention in the field of medical science for their antibacterial, antifungal, antiviral, antitumour, and anticancer activities (Chan et al., 2008;How et al., 2008;Tarafder et al., 2002;Ali et al., 2002;Chew et al., 2004;Crouse et al., 2004) The molecular structure of the title compound is shown in Fig. 1. The Schiff base exists in the thione tautomeric form with the dithiocarbazate fragment adopting an E conformation with respect to the C═N bond of the benzylidene moiety.
The β-nitrogen and the thioketo sulphur are trans located with respect to the C9-N2 bond. The bond lengths and angles are within the normal ranges and are comparable to those in related structures (Tarafder et al., , 2010. The molecule is in its thione tautomeric and the co-planarity of atoms (with the exception of the S-hexyl chain) indicates an electron delocalization within it. The molecule, when used in coordination chemistry, requires a rotation about the C9-N2 by 180 ° in order to allow the N,S chelating behavior towards the metal atom (Islam et al., 2011).
In the crystal, molecules are linked by pairs of N-H···S hydrogen bonds forming inversion dimers with an R 2 2 (8) ring motif (Table 1 and Fig. 2). The dimers are linked via C-H···π interactions forming chains propagating along the a axis direction (Table 1).

Figure 1
A view of the molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
A partial view along the a axis of the crystal packing of the title compound. The hydrogen bonds are shown as dashed lines (see Table 1 for details; H atoms not involved in hydrogen bonding have been omitted for clarity). where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.43 e Å −3 Δρ min = −0.26 e Å −3

Special details
Experimental. 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. Geometry. ENTER SPECIAL DETAILS OF THE MOLECULAR GEOMETRY Refinement. Refinement was performed using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F 2 . R-factor (gt) are based on F. The threshold expression of F 2 > 2.0 σ(F 2 ) is used only for calculating R-factor (gt).