3,4-Dinitro-2,5-bis­[4-(trifluoro­meth­yl)phen­yl]thio­phene

Ping-Hsin Huang; Jiun-Yi Shen; Yuh-Sheng Wen

doi:10.1107/S1600536809020443

. 2009 Jun 6;65(Pt 7):o1469. doi: 10.1107/S1600536809020443

3,4-Dinitro-2,5-bis[4-(trifluoromethyl)phenyl]thiophene

Ping-Hsin Huang ^a,^*, Jiun-Yi Shen ^b, Yuh-Sheng Wen ^b

PMCID: PMC2969454 PMID: 21582772

Abstract

The title compound, C₁₈H₈F₆N₂O₄S, is a precursor for the production of low-band-gap conjugated polymers. In the crystal structure, the dihedral angles between the thiophene and benzene rings are 35.90 (8) and 61.94 (8)°, and that between the two benzene rings is 40.18 (8)°. The two nitro groups are twisted with respect to the thiophene ring, the dihedral angles being 53.66 (10) and 31.63 (10)°. Weak intermolecular C—H⋯O hydrogen bonding helps to stabilize the crystal structure.

Related literature

For a related structure, see: Bak et al. (1961 ▶).

Experimental

Crystal data

C₁₈H₈F₆N₂O₄S
M _r = 462.32
Orthorhombic,
a = 8.1572 (3) Å
b = 17.6371 (6) Å
c = 24.4150 (8) Å
V = 3512.6 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.28 mm⁻¹
T = 100 K
0.4 × 0.36 × 0.1 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.895, T _max = 0.973
22650 measured reflections
3098 independent reflections
1888 reflections with I > 2σ(I)
R _int = 0.058

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.053
S = 0.80
3098 reflections
281 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); 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: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809020443/xu2528sup1.cif

e-65-o1469-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809020443/xu2528Isup2.hkl

e-65-o1469-Isup2.hkl^{(149KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C13—H13⋯O4ⁱ	0.93	2.52	3.320 (2)	144

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was partially supported by the Institute of Chemistry, Academia Sinica, and Cardinal Tien College of Healthcare and Management.

supplementary crystallographic information

Comment

The title compound, (I), has been shown to be an excellent precursor for the production of low band gap conjugated polymers and organic light-emitting devices etc. As indicated in Scheme 2, standard procedures were administrated to synthesize in high yield. The molecular structure is shown in Fig. 1. The double bonds and C—C single bond of (I) are slightly shorter than those of the parent thiophene, while the S—C single bond is slightly elongated (Bak et al., 1961). The dihedral angles between the thiophene (S/C1–C4) and benzene rings (C11–C16 and C21–C26) are 35.90 (8) and 61.94 (8)°, respectively, and that between the two benzene rings is 40.18 (8)°. The two nitro groups are oriented at the thiophene ring with the dihedral angles of 53.66 (10) and 31.63 (10)°, respectively. Intermolecular weak C—H···O hydrogen bonding helps to stabilize the crystal structure (Table 1).

Experimental

The compound was synthesized by the following procedure. A two-necked round-bottomed flask was charged with Pd(PPh₃)₄ (280 mg), tributyl(4-(trifluoromethyl)phenyl)stannane (3.26 g, 7.5 mmol), 2,5-dibromo-3,4-dinitrothiophene (1.00 g, 3.0 mmol) and DMF (20 ml), and the reaction mixture stirred under nitrogen and heated at 343 K for 48 h. After cooling, the mixture was diluted with diethyl ether and the organic phase was washed with water and brine. After drying over anhydrous MgSO₄ and removing the volatiles, the residue was purified by column chromatography using CH₂Cl₂/n-hexane as eluent, followed by recrystallization from CH₂Cl₂ and hexane to yield 0.7 g (50%) of (I) as a white solid. Crystals suitable for X-ray diffraction were grown from a CH₂Cl₂ solution layered with hexane at room temperature.