Acta Cryst. (2009). E65, o952 [ doi:10.1107/S1600536809011647 ]
The title compound, C8H2Br4S2, was prepared by bromination of 2,2'-bithiophene with bromine. The molecule is located on a crystallographic twofold rotation axis, thereby imposing equal geometry of the two thiophene rings. Each five-membered ring is planar [maximum deviation 0.011 (9) Å] and the dihedral angle between the planes through the rings is 47.2 (4)°. The molecules are arranged to minimize intramolecular contacts between the 3-3' and 5-5'-bromine atoms.
The title compound was prepared as reported in the literature (Lin et al., 2005). Single crystals suitable for X-ray diffraction measurement were obtained by slow evaporation of a solution in ethanol (m.p. 413 K; literature value: 413–414 K (Takahashi et al., 2006)).
All H atoms were placed at calculated positions and refined using a riding model approximation, with C—H = 0.93 Å and with Uiso(H) = 1.2Ueq(C).
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
![[Figure 1]](./kj2109fig1thm.gif)
| Fig. 1. A view of the molecule of the title compound. Displacement ellipsoids are drawn at the 30% probability level. |
| C8H2Br4S2 | Dx = 2.756 Mg m−3 |
| Mr = 481.86 | Melting point = 413–414 K |
| Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
| a = 17.164 (3) Å | Cell parameters from 1249 reflections |
| b = 4.0153 (7) Å | θ = 4.8–55.3° |
| c = 18.655 (3) Å | µ = 14.18 mm−1 |
| β = 115.395 (3)° | T = 293 K |
| V = 1161.4 (4) Å3 | Prismatic, yellow |
| Z = 4 | 0.40 × 0.17 × 0.05 mm |
| F(000) = 888 |
| Bruker SMART CCD area-detector diffractometer | 1077 independent reflections |
| Radiation source: fine-focus sealed tube | 886 reflections with I > 2σ(I) |
| graphite | Rint = 0.146 |
| φ and ω scans | θmax = 25.5°, θmin = 2.4° |
| Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | h = −20→18 |
| Tmin = 0.258, Tmax = 1.000 | k = −4→4 |
| 2792 measured reflections | l = −22→21 |
| Refinement on F2 | Primary atom site location: structure-invariant direct methods |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.078 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.208 | H-atom parameters constrained |
| S = 1.00 | w = 1/[σ2(Fo2) + (0.1428P)2] where P = (Fo2 + 2Fc2)/3 |
| 1077 reflections | (Δ/σ)max < 0.001 |
| 64 parameters | Δρmax = 1.15 e Å−3 |
| 0 restraints | Δρmin = −1.06 e Å−3 |
| C8H2Br4S2 | V = 1161.4 (4) Å3 |
| Mr = 481.86 | Z = 4 |
| Monoclinic, C2/c | Mo Kα radiation |
| a = 17.164 (3) Å | µ = 14.18 mm−1 |
| b = 4.0153 (7) Å | T = 293 K |
| c = 18.655 (3) Å | 0.40 × 0.17 × 0.05 mm |
| β = 115.395 (3)° |
| Bruker SMART CCD area-detector diffractometer | 1077 independent reflections |
| Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | 886 reflections with I > 2σ(I) |
| Tmin = 0.258, Tmax = 1.000 | Rint = 0.146 |
| 2792 measured reflections | θmax = 25.5° |
| R[F2 > 2σ(F2)] = 0.078 | H-atom parameters constrained |
| wR(F2) = 0.208 | Δρmax = 1.15 e Å−3 |
| S = 1.00 | Δρmin = −1.06 e Å−3 |
| 1077 reflections | Absolute structure: ? |
| 64 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
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 F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
| x | y | z | Uiso*/Ueq | ||
| Br1 | 0.17755 (6) | 0.2991 (3) | 0.27753 (6) | 0.0443 (5) | |
| Br2 | 0.11718 (8) | 0.7463 (3) | 0.54198 (6) | 0.0562 (5) | |
| S1 | −0.00225 (17) | 0.7354 (6) | 0.36201 (13) | 0.0393 (7) | |
| C1 | 0.0301 (5) | 0.581 (2) | 0.2918 (4) | 0.0331 (17) | |
| C2 | 0.1140 (5) | 0.480 (2) | 0.3291 (4) | 0.0354 (17) | |
| C4 | 0.0973 (6) | 0.650 (2) | 0.4373 (5) | 0.041 (2) | |
| C3 | 0.1540 (5) | 0.521 (2) | 0.4129 (4) | 0.0411 (19) | |
| H3 | 0.2109 | 0.4669 | 0.4459 | 0.049* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Br1 | 0.0524 (7) | 0.0457 (7) | 0.0483 (7) | 0.0023 (4) | 0.0344 (6) | −0.0050 (4) |
| Br2 | 0.0735 (9) | 0.0718 (9) | 0.0312 (7) | −0.0072 (5) | 0.0298 (6) | −0.0063 (4) |
| S1 | 0.0508 (15) | 0.0482 (13) | 0.0306 (12) | 0.0043 (9) | 0.0286 (11) | −0.0007 (8) |
| C1 | 0.050 (5) | 0.030 (4) | 0.034 (4) | 0.000 (4) | 0.032 (4) | 0.000 (3) |
| C2 | 0.052 (5) | 0.030 (4) | 0.034 (4) | −0.006 (3) | 0.028 (4) | 0.001 (3) |
| C4 | 0.059 (6) | 0.042 (5) | 0.028 (4) | 0.003 (4) | 0.025 (4) | 0.006 (3) |
| C3 | 0.050 (5) | 0.046 (5) | 0.035 (4) | −0.003 (4) | 0.025 (4) | 0.005 (4) |
| Br1—C2 | 1.882 (8) | C1—C1i | 1.455 (15) |
| Br2—C4 | 1.873 (8) | C2—C3 | 1.422 (11) |
| S1—C4 | 1.719 (9) | C4—C3 | 1.342 (11) |
| S1—C1 | 1.741 (7) | C3—H3 | 0.9300 |
| C1—C2 | 1.365 (11) | ||
| C4—S1—C1 | 91.0 (4) | C3—C4—S1 | 114.3 (6) |
| C2—C1—C1i | 131.0 (8) | C3—C4—Br2 | 126.8 (7) |
| C2—C1—S1 | 109.2 (6) | S1—C4—Br2 | 118.9 (5) |
| C1i—C1—S1 | 119.8 (7) | C4—C3—C2 | 109.8 (8) |
| C1—C2—C3 | 115.6 (7) | C4—C3—H3 | 125.1 |
| C1—C2—Br1 | 124.7 (6) | C2—C3—H3 | 125.1 |
| C3—C2—Br1 | 119.6 (6) | ||
| C4—S1—C1—C2 | −0.9 (6) | C1—S1—C4—C3 | 1.7 (7) |
| C4—S1—C1—C1i | 179.8 (5) | C1—S1—C4—Br2 | −179.2 (5) |
| C1i—C1—C2—C3 | 179.2 (5) | S1—C4—C3—C2 | −1.9 (10) |
| S1—C1—C2—C3 | 0.1 (9) | Br2—C4—C3—C2 | 179.1 (6) |
| C1i—C1—C2—Br1 | −0.2 (11) | C1—C2—C3—C4 | 1.2 (11) |
| S1—C1—C2—Br1 | −179.4 (4) | Br1—C2—C3—C4 | −179.4 (6) |
| Symmetry codes: (i) −x, y, −z+1/2. |
Financial support of this project by the Program for Changjiang Scholars and Innovative Research Team in Universities (No. IRT0526) and Shanghai Natural Science Foundation (No. 06ZR14001) is acknowledged.
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3,3',5,5'-Tetrabromo-2,2'-bithiophene is an important intermediate compound in the synthesis of oligothiophenes and polythiophenes which have recently attracted attention as materials showing conductive, semiconductive, nonlinear optical (NLO), and liquid crystalline characteristics (Roncali, 1997; Funahashi et al., 2005). While synthesis of 3,3',5,5'-tetrabromo-2,2'-bithiophene could be achieved by coupling of 2,3-dibromothiophene (Takahashi et al., 2006) or bromination of 2,2'-bithiophene (Lin et al., 2005), its single crystal structure has not been reported. Herein we present the single crystal structure of the title compound. A molecule of the title compound is located on a crystallographic two-fold rotation axis, thereby imposing equal geometry of the two rings. Each 5-membered ring is planar and the dihedral angle between the planes thorugh the rings is 47.2 (4)°. The molecules arrange in such a fashion that both pairs of bromine atoms (3- and 3'-bromine and 5- and 5'-bromine) lie far away to each other.