Bis[N-benzyl-N-(2-phenylethyl)dithiocarbamato-κ2 S,S′]lead(II)

The molecule of the title compound, [Pb(C16H16NS2)2], is located on a twofold rotation axis, which runs through the PbII atom. The two dithiocarbamate ligands coordinate the metal in a pyramidal configuration through the S atoms. The two phenyl rings of each dithocarbamate ligand are aligned at a dihedral angle of 78.4 (1)°. The molecular conformation is stabilized by intramolecular C—H⋯S interactions.

The molecule of the title compound, [Pb(C 16 H 16 NS 2 ) 2 ], is located on a twofold rotation axis, which runs through the Pb II atom. The two dithiocarbamate ligands coordinate the metal in a pyramidal configuration through the S atoms. The two phenyl rings of each dithocarbamate ligand are aligned at a dihedral angle of 78.4 (1) . The molecular conformation is stabilized by intramolecular C-HÁ Á ÁS interactions.

Comment
The solid state structural chemistry of lead dithiocarbamates is rich and fascinating in that different structural motifs are found ranging from monomeric, dimeric, tetrameric to linear chain (Davidovich et al., 2010). Metal dithiocarbamate complexes have proven to be very successful as single source precursors for the preparation of metal sulfide nanoparticles (Picket & O′Brien, 2001;Srinivasan & Thirumaran, 2012). The title compound was also used as single source precursor for the synthesis of PbS nanoparticles (Sathiyaraj & Thirumaran, 2012). There is an indication that the molecular structure of the synthetic precursor may influence both the size and morphology of the nanoparticles (Green et al., 2004;Koh et al., 2003). In view of these importance we have undertaken the crystal structure determination of the title compound, and the results are presented here.
The X-ray study confirmed the molecular structure and atomic connectivity for (I), as illustrated in Fig. 1.
The structure consists of monomeric molecules composed of one Pb atom and two chelating dithiocarbamate ligands.
The two dithiocarbamate ligands are coordinated through S atoms to the metal pyramidally and in each chelate ring one Pb-S bond is significantly shorter than other. The relative bond distances and angles for the title compound agree with the presence of an electron lone pair at an equatorial position of a distorted trigonal bipyramid PbS 4 . Evidence for the presence of a stereochemically active electron lone pair of the lead atom has also been reported for other lead complexes (Davidovich et al., 2010).
The sum of the angles at N1 [359.8°] is in accordance with sp 2 hybridization. Two phenyl rings in dithiocarbmate ligand is make a dihedral angle of 78.4 (1) °.
In addition to the van der Waals interactions, the molecular structure is influenced only by intramolecular C-H···S hydrogen bonds involving atoms S1 and S2. (Fig. 2 and Table 1).

Experimental
The title compound was prepared according to the literature procedure (Sathiyaraj & Thirumaran, 2012). Single crystals were obtained by slow evaporation of dichloromethane and acetone (1:1) solution of the title compound at room temperature.

Refinement
H atoms were placed in idealized positions and allowed to ride on their parent atoms, with C-H distances of 0.93-0.97 Å, and Uiso(H) = 1.2U eq (C) for H atoms.

Figure 1
The molecular structure of the title compound, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

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. 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 Pb1