1,2-Bis(undecylsulfanyl)benzene

In the title compound, C28H50S2, the alkyl chains adopt a fully extended all-trans conformation and each of them is almost perfectly planar. One of the alkyl chains is coplanar with the benzene ring and the other is twisted out of the benzene ring plane; the C—C—S—C torsion angles are 176.4 (2) and 80.8 (3)°. In the crystal structure, an intermolecular S⋯S interaction [3.2123 (13) Å] links the molecules into a centrosymmetric dimer; dimers are linked through weak C—H⋯π and C—H⋯S interactions, forming a column along the a axis.


supporting information
Thioethers have emerged as preeminent classes of organic compounds, which hold useful applications as key reagents in organic synthesis, bio-organic, mechanical, and heterocyclic chemistry. The coordination chemistry of dithiolate ligands has also been extensively studied (Liu et al., 2007;Alves et al., 2004;Huynh et al., 2002). In recent years, transition metal bis(dithiolene) complexes, with square-planar coordination geometry, have been used widely as building blocks for conducting and magnetic materials (Robertson & Cronin, 2002). We previously reported the crystal structure of a dithiolate complex salt (Tomiyama et al., 2007). In order to explore crystal structures of new dithiole compounds and to gain more insight into the structure-regulating ability of intermolecular S···S, C-H···S interactions, the title compound was synthesized and its structure was analysized by X-ray analysis.
The structure of the title molecule is shown in Fig. 1. The alkyl chains are in the fully extended all-trans conformation and each alkyl chain is almost perfectly planar. The C8-C7-S1-C1 and C19-C18-S2-C6 torsion angles of 176.4 (2)° and 80.8 (3)°, respectively, indicate that non-hydrogen atoms of one of the side chains is coplanar with the benzene ring, and the other chain is twisted out of the benzene plane.

S3. Refinement
All H atoms were positioned geometrically and allowed to ride on their attached atoms, with C-H = 0.95-0.99 Å and U iso = 1.2U eq (C) or 1.5U eq (methyl C).  An ORTEPIII (Burnett & Johnson, 1996) view of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme.

Figure 2
A partial packing diagram of the title compound, showing symmetrically paired molecules. S···S interactions are shown by dashed lines.

Special details
Experimental. The first 50 frames were rescanned at the end of data collection to evaluate any possible decay phenomenon. Since it was judged to be negligible, no decay correction was applied to the data. Rms deviation of fitted atoms = 0.0000 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 > σ(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 C1 0.3636 (