1-Methyl-4-({5-[(4-methylphenyl)sulfanyl]pentyl}sulfanyl)benzene

There are two independent molecules in the asymmetric unit of the title compound, C19H24S2. In both molecules, the aliphatic segment of the ligand is in an all-trans conformation: the –S–(CH2)5–S–bridging chain is almost planar (r.m.s. deviation for all non-H atoms = 0.0393 and 0.0796 Å in the two molecules) and maximally extended. Their mean planes form dihedral angles of 4.08 (6)/20.47 (6) and 2.22 (6)/58.19 (6)° with the aromatic rings in the two molecules. The crystal packing is purely governed by weak intermolecular forces.

There are two independent molecules in the asymmetric unit of the title compound, C 19 H 24 S 2 . In both molecules, the aliphatic segment of the ligand is in an all-trans conformation: the -S-(CH 2 ) 5 -S-bridging chain is almost planar (r.m.s. deviation for all non-H atoms = 0.0393 and 0.0796 Å in the two molecules) and maximally extended. Their mean planes form dihedral angles of 4.08 (6)/20.47 (6) and 2.22 (6)/ 58.19 (6) with the aromatic rings in the two molecules. The crystal packing is purely governed by weak intermolecular forces.

S1. Comment
In recent years, the rational design of coordination polymers based on multitopic bridging ligands and metal centers represents one of the most rapidly developing fields owing to their potential as functional materials (Guo et al., 2002;Melcer et al., 2001). The use of flexible ligands in such studies has attracted increasing attention because the flexibility and conformational freedom of such ligands offer the possibility for the construction of diverse frameworks with tailored properties and functions (Bu et al., 2001;Withersby et al., 1997).
The structure of the title compound is described here as part of our work involving the study of the synthesis and structural characterization of divalent-sulfur compounds (Brito et al., 2004(Brito et al., , 2005(Brito et al., , 2006. In both molecules the aliphatic segment of this ligand is in an all-trans conformation. The bridging chain moiety, -S-(CH 2 ) 5 -S-, is almost planar (r.m.s. deviation for all non-H atoms: 0.0393 and 0.0796 Å). Its mean planes form a dihedral angle of 4.08 (6) and 20.47 (6)°; 2.22 (6) and 58.19 (6)° with the aromatic rings in the molecules A and B, respectively. The conformation of the central -S-(CH 2 ) 5 -S-fragment is maximally extended. The average S-Csp 2 bond distance of 1.7717 (12) Å is considerably shorter than the average S-Csp 3 distance of 1.8151 (12) Å; corresponding bond distances in several phenylthioether compounds (Murray & Hartley, 1981) are 1.75 and 1.81Å respectively. The bond angles at sulfur [average 103.8 (6)°] are less than tetrahedral as is usually found in simple sulfides.

S3. Refinement
Hydrogen atoms were located in a difference Fourier map but they were included in calculated positions [C-H = 0.95 -0.99 Å] and refined as riding [U iso (H) = 1.2U eq (C) or 1.5U eq (C methyl )]. The methyl groups in one molecule were refined as being disordered over two equally populated sites. All methyl groups were allowed to rotate but not to tip.  Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.

1-Methyl-4-({5-[(4-methylphenyl)sulfanyl]pentyl}sulfanyl)benzene
Crystal data (7)   Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > 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.