4,4′,5,5′-Tetra­kis(benzyl­sulfan­yl)tetra­thia­fulvalene

Cheng-Xiang Yu; Yu-Lan Zhu; Zhao-Xiang Chen; Ming-Zhu Lu; Kun Wang

doi:10.1107/S1600536811007823

. 2011 Mar 9;67(Pt 4):o821. doi: 10.1107/S1600536811007823

4,4′,5,5′-Tetrakis(benzylsulfanyl)tetrathiafulvalene

Cheng-Xiang Yu ^a, Yu-Lan Zhu ^b,^*, Zhao-Xiang Chen ^b, Ming-Zhu Lu ^b, Kun Wang ^a

PMCID: PMC3099894 PMID: 21754105

Abstract

The asymmetric unit of the title compound, C₃₄H₂₈S₈, contains two crystallographically independent half-molecules. The molecules lie on centers of inversion. The four benzene rings of each molecule are substantially twisted from the planes of the 1,3-dithiole rings, forming dihedral angles of 43.6 (2) and 61.4 (1)° in one molecule and 54.2 (1) and 65.2 (1)° in the other.

Related literature

For related structures, see: Abashev et al. (2003 ▶); Wang et al. (1997 ▶). For the synthesis of 4,5-bis(3-picolylthio)-1,3-dithiole-2-thione, see: see: Jia et al. (2001 ▶). For tetrathiafulvalene derivatives, see: Shibaeva & Yagubskii (2004 ▶); Varma et al. (1987 ▶); Williams et al. (1984 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₃₄H₂₈S₈
M _r = 693.04
Triclinic,
a = 5.7450 (7) Å
b = 17.052 (2) Å
c = 18.701 (3) Å
α = 115.199 (2)°
β = 95.238 (2)°
γ = 95.922 (2)°
V = 1630.1 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.57 mm⁻¹
T = 296 K
0.3 × 0.2 × 0.1 mm

Data collection

Bruker SMART APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.871, T _max = 0.944
11631 measured reflections
5688 independent reflections
3518 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.157
S = 1.06
5688 reflections
379 parameters
H-atom parameters constrained
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, New_Global_Publ_Block. DOI: 10.1107/S1600536811007823/zq2088sup1.cif

e-67-0o821-sup1.cif^{(25.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811007823/zq2088Isup2.hkl

e-67-0o821-Isup2.hkl^{(278.4KB, hkl)}

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

Acknowledgments

The authors thank the National Natural Science Foundation of China (Nos. 20671038, 20975043) and the Jiangsu Key Laboratory for the Chemistry of Low Dimensional Materials (No. JSKC09061). They also thank Dr K.-R. Ma for assistance with the crystallographic analysis.

supplementary crystallographic information

Comment

Many researchers have focused on a particularly important class of complexes with TTF (tetrathiafulvalene) and BEDT-TTF [bis(ethylenedithio)tetrathiafulvalene] derivatives (Shibaeva & Yagubskii, 2004; Varma et al., 1987). They have found related the wide range of technological applications, such as high electronic conductivity or superconductivity (Williams et al., 1984). In order to obtain materials involved in nonlinear optics, opto-electronics, molecular electronics, currently, our research is focused on the synthesis and crystal structures of TTF derivatives.

The asymmetric unit of the title compound, C₃₄H₂₈S₈, contains two crystallographically independent half-molecules. The molecules lie on centers of inversion. They adopt chair-like conformations and the four benzene rings of each molecule are severely twisted from the planarity of the 1,3-dithiole rings (Fig. 1). Due to the C_i symmetry of the molecules, the substituent groups of the TTF core are located in opposite directions, resulting in chair-like molecular conformations. The four benzene rings of each molecule are severely twisted from the planarity of the 1,3-dithiole rings. The C—S bonds in the five-membered rings fall in the range of 1.742 (4)–1.761 (4) Å and are shorter than a typical C—S single bond (1.82 Å; Allen et al., 1987), revealing the high degree of conjugation into the five-membered rings of the title compound. On the other hand, the S—C(CH₂Ph) bond distances are longer than the C-S bonds of the rings falling in the range of 1.794 (5)-1.837 (5) Å, similar to a typical C—S single bond. The mean planes of the C5–C10 and C12–C13 benzene rings [C22–C27 and C29–C34] form dihedral angles of 43.6 (2) and 61.4 (1)° [54.2 (1) and 65.2 (1)°] with the least-squares plane of the central dithiolane ring, respectively. The crystal packing diagram of the title compound is shown in Fig. 2. The shortest intermolecular S-S distances, S(1)—S(2) and S(5)—S(6) distances, are 3.793 (2) Å and 3.855 (2) Å, respectively.

Experimental

A total of 42.15 mg (0.3 mmol) of K₂CO₃ was dissolved in less than 5 ml of water, and 100 mg (0.61 mmol) of 3-picolyl chloride hydrochloride was added at room temperature. After the gas evolution was stopped, a colorless dense liquid was present. Subsequently, 143.35 mg (0.15 mmol) of TBA2[Zn(DMIT)2] dissolved in 15 ml of acetonitrile was mixed with this dense liquid, and the solution was stirred at 50–60 °C for 1.5–2 h. The reaction mixture was filtered, and the solid residue was washed twice with dichloromethane (20 ml). The combined filtrate and washings were decolorized by activated charcoal. After removing the solvent, column chromatography of the crude reaction mixture on silica gel with ethyl acetate/methanol (10:1) afforded compound 1a as a yellow solid (85.5 mg, 75%). Benzyl chloride (12 ml) was added dropwise to a solution of TBA2[Zn(DMIT)2] (10 mmol) in acetone (100 ml). The mixture was refluxed under N₂ for 24 h. Stirring was continued overnight. The resulting orange precipitate was filtered off. The product was further purified by recrystallization from methanol to give yellow needle like crystals (yield 76%). All solvent were distilled before use. 95 mg (0.25 mmol) of 4,5-bis(3-picolylthio)-1,3-dithiole-2-thione and 144 mg (0.4 mmol) of 4,5- bis(benzylthio)-1,3-dithione- 2-thione (0.3 mmol) were stirred in 30 ml of dry toluene under N₂. Then, 2.5 ml of P(OEt)₃ was added and the yellowish suspension was refluxed for 4 h at 120 °C. The resulting orange yellow precipitate that formed was filtered off. The red filtrate was left to stand for several days, giving pale red crystals suitable for a X-ray structure analysis.