Bis[benzyl 3-(3-phenylprop-2-enylidene)dithiocarbazato-κ2 N 3,S]cadmium

In the title complex, [Cd(C17H15N2S2)2], the CdII ion is located on a twofold rotation axis and exhibits a coordination number of four within a very distorted coordination environment that is best described as bisphenoidal. The two deprotonated Schiff base ligands chelate the CdII ion through the azomethine N and the thiolate S atom. The dihedral angle between the two chelating ligands is 84.01 (9)°. Weak intermolecular C—H⋯S interactions lead to the formation of chains along the c axis.

In the title complex, [Cd(C 17 H 15 N 2 S 2 ) 2 ], the Cd II ion is located on a twofold rotation axis and exhibits a coordination number of four within a very distorted coordination environment that is best described as bisphenoidal. The two deprotonated Schiff base ligands chelate the Cd II ion through the azomethine N and the thiolate S atom. The dihedral angle between the two chelating ligands is 84.01 (9) . Weak intermolecular C-HÁ Á ÁS interactions lead to the formation of chains along the c axis.

Related literature
For the structure of uncoordinated Schiff bases, see  ;. For the isotypic Zn and Hg analogues, see: Fun et al. (2008); Islam et al. (2012). For the coordination behaviour of metal ions (Co, Ni, Cu, Zn, Cd and Hg) with the cinnamaldehyde Schiff base of S-methyldithiocarbazate, see: Liu et al. (2009); Abram et al. (2006). For the bioactivity of transition metal complexes of similar Schiff base ligands, see: Chew et al. (2004); How et al. (2008); Maia et al. (2010).
Cd-N1 2.306 (2) Cd-S1 2.4285 (9) N1 i -Cd-N1 103.00 (12) N1 i -Cd-S1 119.99 (6) N1-Cd-S1 80.27 (6) S1-Cd-S1 i 149.19 (5) Symmetry code: (i) Àx þ 1; y; Àz þ 3 2 . Table 2 Hydrogen-bond geometry (Å , ). In continuation of our interest in exploring the chemistry of Schiff bases derived from S-benzyldithiocarbazate  and of their metal complexes, due to their intriguing coordination behaviour, physico-chemical properties, and potential biological activities, we have completed the syntheses of group 12 In the present complex the Cd II ion lies on a twofold rotation axis and therefore the asymmetric unit contains one-half of the molecule (Fig. 1). The fourfold coordination is best described as bisphenoidal, with the Cd II ion being chelated by two benzyl N′-(3-phenylprop-2-enylidene)dithiocarbazate ligands through the azomethine nitrogen and the thiolate sulfur donors. The two chelating five-membered rings form a dihedral angle of 84.01 (9)°. Since the structure is isotypic with those of Zn  and Hg (Islam et al., 2012), it is worthwhile to compare the geometries around the metal ions. The M-N bond lengths in the series follow the trend Zn < Cd < Hg (2.0662 (12) The crystal packing is consolidated by weak C13-H13···S2 interactions , giving rise to a chain motif extending along the c axis.

Experimental
The Schiff base, benzyl N′-(3-phenylprop-2-enylidene)hydrazinecarbodithioate was prepared as prevoiusly reported . Cadmium(II) acetate dihydrate (0.066 g, 0.25 mmol) dissolved in absolute ethanol (20 ml) was added to a hot absolute ethanol solution (50 ml) of the Schiff base (0.163 g, 0.5 mmol) under refluxing condition, which was continued for 2 h. The yellow precipitate which formed was filtered off, washed with hot ethanol and dried in vacuo over anhydrous CaCl 2 . Yield: 0.199 g (87%). 54 mg of the compound was dissolved in chloroform (10 ml) at room temperature and mixed with toluene (5 ml). The resultant solution was allowed to stand at ambient temperature. Yellow square-shaped flat single crystals developed after 7 days. (m.p.= 438 K).

Refinement
All H atoms were geometrically located and treated as riding atoms, with C-H = 0.95 Å for C(aromatic) and 0.99 Å, for C(methylene), with U iso (H) = 1.2U eq (C). The highest residual electron density peak (1.36 e Å -3 ) is located at 1.09 Å from the Cd atom.

Figure 1
An ORTEP drawing (ellipsoids at the 50% probability level) of the title compound with the atom labelling scheme.

Bis[benzyl 3-(3-phenylprop-2-enylidene)dithiocarbazato-κ 2 N 3 ,S]cadmium
Crystal data [Cd(C 17  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 1.36 e Å −3 Δρ min = −0.52 e Å −3 Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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  (5)