Ethane-1,2-diyl bis­(benzene­dithio­ate)

Daisuke Abe; Yuji Sasanuma; Hiroyasu Sato

doi:10.1107/S1600536811010245

. 2011 Mar 26;67(Pt 4):o961. doi: 10.1107/S1600536811010245

Ethane-1,2-diyl bis(benzenedithioate)

Daisuke Abe ^a, Yuji Sasanuma ^a,^*, Hiroyasu Sato ^b

PMCID: PMC3099809 PMID: 21754225

Abstract

In the crystal structure, the title compound, C₁₆H₁₄S₄, is located on an inversion center and exhibits a gauche⁺–trans–gauche⁻ conformation in the S—CH₂—CH₂—S bond sequence. The S—C=S plane makes a dihedral angle of 30.63 (17)° with the phenyl ring. An intermolecular C—H⋯π interaction is observed.

Related literature

For crystal structures and conformations of related compounds with S—CH₂—CH₂—S bond sequences, see: for example, Takahashi et al. (1968 ▶); Deguire & Brisse (1988 ▶); Sasanuma & Watanabe (2006 ▶).

Experimental

Crystal data

C₁₆H₁₄S₄
M _r = 334.53
Monoclinic,
a = 11.5431 (7) Å
b = 8.74071 (16) Å
c = 8.93720 (16) Å
β = 122.3772 (7)°
V = 761.54 (5) Å³
Z = 2
Cu Kα radiation
μ = 5.60 mm⁻¹
T = 93 K
0.32 × 0.27 × 0.08 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.195, T _max = 0.639
8415 measured reflections
1389 independent reflections
1292 reflections with F ² > 2σ(F ²)
R _int = 0.054

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.079
S = 1.14
1389 reflections
91 parameters
H-atom parameters constrained
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.39 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 1998 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku Americas & Rigaku, 2007 ▶); program(s) used to solve structure: SIR2004 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811010245/is2686sup1.cif

e-67-0o961-sup1.cif^{(13.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811010245/is2686Isup2.hkl

e-67-0o961-Isup2.hkl^{(68.6KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the C1–C6 phenyl ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8A⋯Cg1ⁱ	0.99	2.65	3.451 (1)	138

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Symmetry code: (i) Inline graphic .

Acknowledgments

This study was partly supported by a Grant-in-Aid for Scientific Research (C) (22550190) from the Japan Society for the Promotion of Science.

supplementary crystallographic information

Comment

The S—CH₂—CH₂—S part of crystallized poly(ethylene sulfide) (PES, [–CH₂CH₂S–]_x) lies in the gauche⁺ – trans – gauche^- (g⁺tg^-) conformation (Takahashi et al., 1968); the two S—C bonds are in opposite gauche states, and dipole moments are formed along bisectors of the C—S—C angles. The dipole–dipole interaction was suggested to be the source of its high melting point (215–220 °C) in comparison with that (66–69 °C) of poly(ethylene oxide), [–CH₂CH₂O–]_x (Sasanuma & Watanabe, 2006). Therefore, poly(thioethylenethioterephthaloyl) ([–SCH₂CH₂SCOC₆H₄CO–]_x) and poly(thioethylenethiodithioterephthaloyl) ([–SCH₂CH₂SCSC₆H₄CS–]_x), having the same S—CH₂—CH₂—S bond sequence as PES, are expected to be superior in some physical properties to their homologous polyester, poly(ethylene terephthalate) ([–OCH₂CH₂OCOC₆H₄CO–]_x). Crystal conformations of polymers are requisite to derive their configurational properties and thermodynamic quantities. Because a polymer tends to have a crystal conformation similar to that of its small model compounds, the models provide the physicochemical information on the polymer. The crystal structure of 1,2-bis(benzoylthio)ethane (BBTE, C₆H₅C(=O)SCH₂CH₂SC(=O)C₆H₅), a model compound of poly(thioethylenethioterephthaloyl), was determined already (Deguire & Brisse, 1988); its S—CH₂—CH₂—S part also lies in the g⁺tg^- state. We have investigated structure-property relationships of the above-mentioned polyester, polythioester, and polydithioester. As part of the work, this study has dealt with 1,2-bis(dithiobenzoyl)ethane (BDTBE, C₆H₅C(=S)SCH₂CH₂SC(=S)C₆H₅), a model compounds of poly(thioethylenethiodithioterephthaloyl); the crystal structure has been determined and compared with those of BBTE and PES.

Figure 1 shows the molecular structure of BDTBE. Its S—CH₂—CH₂—S bond sequence adopts the g⁺tg^- conformation, as found for PES and BBTE. The g⁺tg^- conformation renders the two phenyl rings parallel to each other; however, this is partly because the BDTBE molecule is located on the center of symmetry. The C₆H₅—C(=O)—S part of BBTE is essentially coplanar, whereas the C=S bond of BDTBE is out of the phenyl plane; the S–C═S plane makes a dihedral angle of 30.63 (17)° with the phenyl ring. This is probably due to the van der Waals radius (1.80 Å) of sulfur larger than that (1.52 Å) of oxygen.

The BBTE crystal seems to include intermolecular π–π interactions of a near vertical type (Deguire & Brisse, 1988). In addition, dipole moments, formed close to the O=C bonds, are either parallel or antiparallel to one another. The dipole-dipole interactions are known to stabilize the crystal structure (Sasanuma & Watanabe, 2006). On the other hand, Figure 2 shows that the C=S bonds of BDTBE do not have such clear orientations, because the small difference in electronegativity between C and S little polarizes the C=S bond. In the BDTBE crystal, instead, C—H···π interactions appear to exist between C8—H8A bond and its neighboring phenyl (Ph) ring, and the H···Ph spacing can be estimated to be 2.65 Å.

Experimental

Benzoyl chloride (19.5 g) was added dropwise into 1,2-ethanedithiol (6.2 g) and pyridine (11 ml) in a four-neck flask equipped with a mechanical stirrer and a reflux condenser, and the mixture was stirred at 0 °C for 30 m and, furthermore, at room temperature overnight. The reaction mixture was subjected to extraction with water and ether. The organic layer was washed three times with 8% sodium hydrogen carbonate solution, dried overnight over anhydrous magnesium sulfate, filtrated, and condensed on a rotary evaporator. The residue was recrystallized twice from ethanol and dried under reduced pressure. 1,2-Bis(benzoylthio)ethane (1.5 g) thus prepared, Lawesson's reagent (2.5 g), and toluene (10 ml) were mixed and refluxed for 5 h. The reaction mixture was condensed, dissolved in a mixed solvent (15 ml) of toluene and n-hexane (volume ratio 1:3), and fractionated by a silica-gel column chromatograph. The reddish fraction was collected, condensed, recrystallized twice from ethanol, and dried in vacuo.

Crystals for X-ray diffraction were prepared by slow evaporation of a dimethyl sulfoxide solution. Then, the solution was kept in an open vessel so that water vapor, a poor solvent, would be immixed and hasten the crystallization.