Dibenzyl pentathiodicarbonate

In the title compound, C16H14S5, the non-bonded intramolecular distances between the non-terminal S atoms are 2.808 (16) and 2.784 (16) Å, shorter than the typical distance of 2.9 Å. One phenyl ring participates in an offset π-π interaction with another phenyl ring related by a centre of inversion; the interplanar distance is 3.41 (2) Å. The crystal structure also exhibits edge-to-face C—H⋯π stacking of the phenyl rings, thus forming a herring-bone packing motif.

In the title compound, C 16 H 14 S 5 , the non-bonded intramolecular distances between the non-terminal S atoms are 2.808 (16) and 2.784 (16) Å , shorter than the typical distance of 2.9 Å . One phenyl ring participates in an offsetinteraction with another phenyl ring related by a centre of inversion; the interplanar distance is 3.41 (2) Å . The crystal structure also exhibits edge-to-face C-HÁ Á Á stacking of the phenyl rings, thus forming a herring-bone packing motif.

Dibenzyl pentathiodicarbonate
Wolfgang G. Weber, James B. McLeary, Jan-André Gertenbach and Leigh Loots S1. Comment Di-and trithiocarbonate systems have recently found widespread application as mediators in free radical polymerization (Moad et al., 2005 andMcLeary &Klumperman, 2006). As part of a further investigation of the interaction of these multi-thio compounds with radical species, extended polythiocarbonate systems have been examined. The preparation and characterization of pentathiodicarbonates is presented here. Two new dialkyl pentathiodicarbonates R-S-C(?S)-S-C(?S)-S-R with R = benzyl and tert-butyl were prepared by reaction of potassium benzyl-or tert-butyl-trithiocarbonate, respectively, with 2-chloro-N-methylpyridinium iodide (Scheme 2). The title compound is also formed by the reaction of potassium benzyltrithiocarbonate with benzyl dithiochloroformate (36% yield). The structure and details of the title compound are reported here.
These are shorter than the 2.9 Å separation that is typically associated with distances of this type. The short contact is possible because of the out-of-plane twisting of the two thiono atoms, S2 and S4, and is likely brought about by steric hindrance between these two atoms. The intramolecular non-bonded distance between the two thiono atoms, S2 and S4, is 3.826 (16) Å.
The packing motif is mediated by the benzyl rings at either end of the molecule. For the purposes of this discussion we shall refer to the ring that is made up of C1, C2, C3, C4, C5 and C6 as Ring A and the ring consisting of C11, C12, C13, C14, C15 and C16 as Ring B. Ring A participates in an offset π-π interaction with another Ring A that is related by a centre of inversion. The linking methylene carbon atom (C7) also takes part in the interaction between these units. The interplanar spacing between the planes defined by the atoms of the two benzyl rings is 3.41 (2) Å. On its opposite side, Ring A interacts with a neighbouring Ring B, of a molecule related by 1 + x, y, 1 + z, in an edge-to-face manner where H12 is situated 3.009 (4) Å from the plane defined by the atoms of Ring A.
Packing in the solid state is further mediated by a number of close contacts with neighbouring molecules, although none of the classical H-bond variety. A short intermolecular distance of 2.949 (4) Å is found between S5 and H5 of a molecule related by the 2 -x, -y, 1 -z symmetry operation. S4 is separated from H14 (x, y, 1 + z) and S2 from H3 (x-1,y, z -1) by 2.998 (4) Å and 3.048 (5) Å, respectively. S1 is at a distance of 3.011 Å (4) from H13 (1 + x, y, 1 + z).

S2. Experimental
Potassium benzyltrithiocarbonate was prepared in situ by the reaction of benzyl mercaptan with carbon disulfide in aqueous potassium hydroxide (Degani, et al., 1986) and 2-chloro-N-methylpyridinium iodide from 2-chloropyridine and methyl iodide (Amin et al., 1979). Dibenzyl pentathiodicarbonate was prepared by adding 6.4 g (25 mmol) pyridinium salt within 5 min to a stirred and cooled aqueous solution of 50 mmol of potassium benzyl trithiocarbonate. Stirring continued for another 30 min and the red crystals formed were filtered off and washed several times with water. The crude product can be crystallized from acetonitrile with slow cooling to form larger red crystals. Yield = 7.6 g (83%

Figure 1
The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level.  The preparation of dibenzyl pentathiodicarbonate. 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 > 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.