(N-Benzyl-N-ethyldithiocarbamato)di-tert-butylchloridotin(IV)

The SnIV atom in the title diorganotin dithiocarbamate, [Sn(C4H9)2Cl(C10H12NS2)], is pentacoordinated by an asymmetrically coordinating dithiocarbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups. The resulting C2ClS2 donor set defines a coordination geometry intermediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former. In the crystal structure, C—H⋯π contacts link centrosymmetrically related molecules into dimeric aggregates.

The Sn IV atom in the title diorganotin dithiocarbamate, [Sn(C 4 H 9 ) 2 Cl(C 10 H 12 NS 2 )], is pentacoordinated by an asymmetrically coordinating dithiocarbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups. The resulting C 2 ClS 2 donor set defines a coordination geometry intermediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former. In the crystal structure, C-HÁ Á Á contacts link centrosymmetrically related molecules into dimeric aggregates.
Cg1 is the centroid of the C5-C10 ring.

Comment
Organotin dithiocarbamates attract attention as they exhibit properties suggesting their potential as anti-cancer agents, antimicrobials and insecticides (Tiekink, 2008). Motivated by these and in continuation of structural studies of these systems (Abdul Muthalib et al., 2010), the analysis of the title compound, (I), was undertaken.
The Sn IV atom in (I) is five-coordinated, being chelated by an asymmetrically coordinating dithiocarbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups ( Fig. 1 and Table 1). The asymmetric chelating mode of the non-symmetric dithiocarbamate ligand is reflected in the non-equivalence of the associated C≐S bond distances ( Table 1).
The coordination geometry is intermediate between square pyramidal and trigonal bi-pyramidal with a leaning towards the former. This assignment is based on the value calculated for τ of 0.45 for the Sn atom, which compares to the τ values of 0.0 and 1.0 for ideal square pyramidal and trigonal bi-pyramidal geometries, respectively (Spek, 2009;Addison et al., 1984). The mode of coordination of the dithiocarbamate ligand, the disposition of the ligand donor set, and the intermediate coordination geometry observed for (I) matches with the literature precedents (Tiekink, 2008).
The most prominent feature of the crystal packing is the presence of C-H···π interactions ( Table 2). As shown in Fig. 2, these lead to dimeric aggregates. It is also noted that intramolecular C-H···π contacts are present so that the benzene ring participates in two such interactions (Table 2, Fig. 2). The dimeric aggregates stack into columns along the a axis (Fig. 3).

Experimental
The dithiocarbamate ligand was prepared by the addition of carbon disulfide (0.01 mol) to an ethanolic solution (20 ml) of ethylbenzylamine (0.01 mol). The mixture was stirred for 1 h at 277 K, after which the solution was added drop wise to a solution of di-tert-butyltin(IV) dichloride (0.005 mol) in ethanol (20 ml). The resulting mixture was stirred for 1 h. The white precipitate was filtered, washed with cold ethanol and dried in a desiccator. Crystallization was carried out by using an

Refinement
Carbon-bound H-atoms were placed in calculated positions (C-H = 0.95 to 0.99 Å) and were included in the refinement in the riding model approximation, with U iso (H) set to 1.2 to 1.5U eq (C).
supplementary materials sup-2 Figures Fig. 1. The molecular structure of of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.

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 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 Rfactors(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.