Benzyl 3-[(E,E)-3-phenylprop-2-enylidene]dithiocarbazate

The title compound, C17H16N2S2, a dithiocarbazate derivative, adopts an EE configuration with respect to the C=C and C=N double bonds of the propenylidine group. The 3-phenylprop-2-enylidene and dithiocarbazate fragments lie essentially in the same plane, with a maximum deviation from that plane of 0.074 (2) Å, while the dihedral angle between the 3-phenylprop-2-enylidene and the benzyl group is 77.78 (7)°. In the crystal structure, molecules are linked by an N—H⋯S hydrogen bond and a weak C—H⋯S interaction involving the terminal thione S atom, forming dimers that are arranged into sheets parallel to the bc plane. The crystal structure is also stabilized by C—H⋯π interactions.

The title compound, C 17 H 16 N 2 S 2 , a dithiocarbazate derivative, adopts an EE configuration with respect to the C C and C N double bonds of the propenylidine group. The 3phenylprop-2-enylidene and dithiocarbazate fragments lie essentially in the same plane, with a maximum deviation from that plane of 0.074 (2) Å , while the dihedral angle between the 3-phenylprop-2-enylidene and the benzyl group is 77.78 (7) . In the crystal structure, molecules are linked by an N-HÁ Á ÁS hydrogen bond and a weak C-HÁ Á ÁS interaction involving the terminal thione S atom, forming dimers that are arranged into sheets parallel to the bc plane. The crystal structure is also stabilized by C-HÁ Á Á interactions.

Comment
There has been immense interest in nitrogen-sulfur donor ligands since our report on S-benzyldithiocarbazate (SBDTC) (Ali & Tarafder, 1977). There have also been a number of reports of Schiff bases derived from SBDTC (Ali et al., , 2002(Ali et al., , 2008Chan et al., 2008;Chew et al., 2004;Tarafder et al., 1978Tarafder et al., , 1981Tarafder et al., , 2001Raj et al., 2000). The intriguing coordination chemistry and increasingly important biomedical properties of ligands derived from SBDTC have also received much attention (Ali et al., , 2002Crouse et al., 2004;Tarafder et al., 2001Tarafder et al., , 2008. The synthesis and structure of SBDTC have been reported previously (Ali & Tarafder (1977); Shanmuga Sundara Raj et al., 2000). In continuation of our research, the title compound (I), a ligand with both N and S donor atoms, was synthesized and its crystal structure is reported here. (I) is likely to have biomedical properties similar to other nitrogen-sulfur donor ligands studied by our group.

Experimental
The title compound was synthesized by adding cinnamaldehyde (1.34 g, 10 mmol) to a solution of S-benzyldithiocarbazate (SBDTC) (1.98 g, 10 mmol) in absolute ethanol (60 ml) and the mixture was refluxed for 40 min. The yellow precipitate, which formed was separated and dried in vacuo over anhydrous CaCl 2 (Yield: 2.1 g, 63%). Yellow needle shaped single crystals of (I) were obtained after recrystallization from absolute ethanol over 15 days; M.p 454 K.

Refinement
The H1N1 hydrogen atom was located from a difference Fourier map and refined freely with isotropic displacement parameters. The remaining H atoms were positioned geometrically and allowed to ride on their parent atoms, with d(C-H) = 0.93 Å, for CH and aromatic, 0.97 Å, for CH 2 and U iso = 1.2U eq (C). The highest residual electron density peak is located at 0.96 Å from S1 and the deepest hole is located at 0.72 Å from S1. Fig. 1. The asymmetric unit of the title compound, showing 50% probability displacement ellipsoids and the atomic numbering.

Special details
Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.
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 > 2sigma(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 S1 −0.13630 (