organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

2-(2,2-Di­bromo­ethen­yl)thio­phene

aInstitut UTINAM UMR CNRS 6213, Université de Franche-Comté, 16 Route de Gray, La Bouloie, 25030 Besançon, France, and bAnorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44227 Dortmund, Germany
*Correspondence e-mail: mail@carsten-strohmann.de

(Received 6 December 2010; accepted 18 January 2011; online 22 January 2011)

The title compound, C6H4Br2S, represents a versatile building block for the preparation of π-conjugated redox-active thienyl oligomers and metal-mediated cross-coupling reactions. This is due to the presence of an electrochemically active thienyl heterocycle and a reactive dibromo­vinyl substituent, which easily undergoes dehydro­bromination in the presence of n-butyl­lithium to afford 2-ethynyl­thio­phene. In the molecule, the alkenyl unit and the thio­phene ring are almost coplanar with an angle of 3.5 (2)° between the normals of the best planes of the thio­phene ring and the vinyl moiety.

Related literature

The title compound was first prepared in 1980, see: Bestmann et al. (1980[Bestmann, H. J. & Frey, H. (1980). Liebigs Ann. Chem. pp. 2061-2071.]). For an alternative synthesis using a Corey–Fuchs reaction, see: Beny et al. (1982[Beny, J.-P., Dhawan, S. N., Kagan, J. & Sundlass, S. (1982). J. Org. Chem. 47, 2201-2204.]). For a structural comparison with 2,2-dibromo­vin­yl[2,2]paracyclo­phane [PCP—C(H)=CBr2], (2,2-dibromo­vin­yl)ferrocene [Fc—C(H)=CBr2], and 2-thienyl­methyl­enemalononitrile [C4H3S—C(H)=C(CN)2], see: Clément et al. (2007a[Clément, S., Guyard, L., Knorr, M., Dilsky, S., Strohmann, C. & Arroyo, M. (2007a). J. Organomet. Chem. 692, 839-850.],b[Clément, S., Guyard, L., Knorr, M., Vilafane, F., Strohmann, C. & Kubicki, M. M. (2007b). Eur. J. Inorg. Chem. pp. 5052-5061.]) and Mukherjee et al. (1984[Mukherjee, A. K., Mukherjee (née Mondal), M., De, A. & Bhattacharyya, S. P. (1984). Acta Cryst. C40, 991-992.]), respectively. For recent applications, see: Herz et al. (1999[Herz, H.-G., Queiroz, M. J. R. P. & Maas, G. (1999). Synthesis, pp. 1013-1016]); Rao et al. (2010[Rao, M. L. N., Jadhav, D. N. & Dasgupta, P. (2010). Org. Lett. 12, 2048-2051.]); Zhang et al. (2010[Zhang, A., Zheng, X., Fan, J. & Shen, W. (2010). Tetrahedron Lett. 51, 828-831.]).

[Scheme 1]

Experimental

Crystal data
  • C6H4Br2S

  • Mr = 267.97

  • Monoclinic, P 21 /c

  • a = 9.6843 (19) Å

  • b = 7.2379 (14) Å

  • c = 11.484 (2) Å

  • β = 109.16 (3)°

  • V = 760.4 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 10.84 mm−1

  • T = 173 K

  • 0.4 × 0.4 × 0.2 mm

Data collection
  • Stoe IPDS diffractometer

  • Absorption correction: numerical (FACEIT in IPDS; Stoe & Cie, 1999[Stoe & Cie (1999). IPDS. Stoe & Cie, Darmstadt, Germany.]) Tmin = 0.188, Tmax = 0.658

  • 6492 measured reflections

  • 1667 independent reflections

  • 1444 reflections with I > 2σ(I)

  • Rint = 0.064

Refinement
  • R[F2 > 2σ(F2)] = 0.058

  • wR(F2) = 0.139

  • S = 1.04

  • 1667 reflections

  • 82 parameters

  • H-atom parameters not refined

  • Δρmax = 1.36 e Å−3

  • Δρmin = −1.73 e Å−3

Data collection: EXPOSE in IPDS (Stoe & Cie, 1999[Stoe & Cie (1999). IPDS. Stoe & Cie, Darmstadt, Germany.]); cell refinement: CELL in IPDS; data reduction: INTEGRATE in IPDS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Comment top

The title compound (Scheme 1, Fig. 1), which is easily accessible from thiophene-2-carbaldehyde via the Corey-Fuchs reaction, has over the last 30 years become a versatile starting material for a variety of organic transformations and a precursor in material science. This interest is due to the conjugation between the electrochemically active thienyl heterocycle with the reactive halogenated olefin moiety. Originally it was used for the preparation of terthiophenes (Beny et al., 1982). Recent applications include Pd-catalyzed cross-coupling reactions (Herz et al., 1999; Rao et al., 2010) as well as the synthesis of imidazo[1,5-α]pyridines (Zhang et al., 2010).

In the course of our interest in developing new π-conjugated dihalovinyl compounds R—C(H)CX2 with functional groups (R = imine, ferrocenyl, [2,2]paracyclophane) as substrates for oxidative addition reactions across low-valent noble metals, we have recently reported the synthesis and crystal structures of 4-2',2'-dibromovinyl[2,2]paracyclophane (Clément et al. 2007a) and (2,2-dibromovinyl)ferrocene (Clément et al. 2007b). With this aim in mind, we also prepared the title compound 2-(2,2-dibromoethenyl)thiophene. A survey of the CSD data base revealed that neither 2-vinylthiophene nor a halogenated derivative of the types [C4H3S—C(H)C(H)X] or [C4H3S—C(H)CX2] (X = halogen) had been structurally characterized yet. The most related molecule found is 2-thienylmethylenemalononitrile [C4H3S—C(H)C(CN)2] (Mukherjee et al., 1984). In the latter compound, the angle between the normals of the two planar parts of the molecule, the thiophene cycle and the dicyanovinyl moiety, amounts to 3.6 (5)°. In the title compound, the corresponding angle lies in the same range [3.5 (2)°]. A somewhat larger angle of 10.4° has been determined for (2,2-dibromovinyl)ferrocene [Fc—C(H)CBr2] (Clément et al., 2007b), whereas in 4-(2',2'-dibromovinyl)[2,2]paracyclophane [PCP—C(H)CBr2] an angle of 51.1° has been observed significantly deviating from coplanarity (Clément et al., 2007a). The length of the vinylic C1—C2 double bond [1.335 (7) Å] matches well with those of [PCP—C(H)CBr2] [1.320 (3)°] and [Fc—C(H) CBr2] [1.318 (4) Å] (Clément et al., 2007a; Clément et al., 2007b). A similar bond length of 1.353 (5) Å has also been reported for [C4H3S—C(H)C(CN)2] (Mukherjee et al., 1984).

Bond lenths and angles of the thienyl moiety may be considered as normal and deserve no further comment. The unit cell consists of 4 molecules which are held together by weak interactions only (Fig. 2). These consist of the short Br1—Br2 distance [3.6501 (9) Å, Br1_5-Br2_2] as well as the short distances between Br2 and the carbon atoms of the thiophene ring [3.604 (5) Å, Br2_2-C4; 3.479 (6) Å, Br2_2-C5; 3.624 (5) Å, Br2_2-C6].

Related literature top

The title compound was first prepared in 1980, see: Bestmann et al. (1980). For an alternative synthesis using a Corey–Fuchs reaction, see: Beny et al. (1982). For a structural comparison with 2,2-dibromovinyl[2,2]paracyclophane [PCP—C(H)CBr2], (2,2-dibromovinyl)ferrocene [Fc—C(H)CBr2], and 2-thienylmethylenemalononitrile [C4H3S—C(H)C(CN)2], see: Clément et al. (2007a,b) and Mukherjee et al. (1984), respectively. For recent applications, see: Herz et al. (1999); Rao et al. (2010); Zhang et al. (2010).

Experimental top

Triphenylphosphine (4.20 g, 16.0 mmol), CBr4 (5.31 g, 16.0 mmol) and zinc dust (1.05 g, 16.0 mmol) were placed in a Schlenk tube and 40 ml of CH2Cl2 were slowly added. The mixture was stirred at room temperature for 28 h. Then, 2-thiophenecarboxaldehyde (0.89 g, 8.00 mmol) in CH2Cl2 (10 ml) was added and stirring was continued for further 2 h. The reaction mixture was extracted with three 50 ml portions of pentane. CH2Cl2 was added when the reaction mixture became too viscous for further extractions. The extracts were filtered and evaporated under reduced pressure. The crude product was purified by column chromatography on silica gel with CH2Cl2/petroleum ether (1:4). Slow evaporation afforded white crystals of 2-(2,2-dibromoethenyl)thiophene (yield: 90%). Characterization data have been previously described in the literature. (Beny et al., 1982)

Refinement top

H atoms were refined using a riding model in their ideal geometric positions using the riding model approximation with Uiso(H) = 1.2Ueq(C) for all H atoms.

Computing details top

Data collection: EXPOSE in IPDS (Stoe & Cie, 1999); cell refinement: CELL in IPDS (Stoe & Cie, 1999); data reduction: INTEGRATE in IPDS (Stoe & Cie, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound with thermal ellipsoids drawn at the 50% probability level.
[Figure 2] Fig. 2. Crystal packing of 2-(2,2-dibromoethenyl)thiophene. Symmetry operations: (1) x, y, z; (2) -x, y - 1/2, -z - 1/2; (3) -x, -y - 1, -z; (4) x, -y + 1/2, z - 1/2; (5) x - 1, y, z; (6) x, y -1, z; (7) x - 1, -y + 1/2, z - 1/2; (8) -x, -y - 1, -z - 1.
2-(2,2-Dibromoethenyl)thiophene top
Crystal data top
C6H4Br2SF(000) = 504
Mr = 267.97Dx = 2.341 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 980 reflections
a = 9.6843 (19) Åθ = 2.2–27.0°
b = 7.2379 (14) ŵ = 10.84 mm1
c = 11.484 (2) ÅT = 173 K
β = 109.16 (3)°Plates, colourless
V = 760.4 (3) Å30.4 × 0.4 × 0.2 mm
Z = 4
Data collection top
Stoe IPDS
diffractometer
1444 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.064
ϕ scansθmax = 27.0°, θmin = 2.2°
Absorption correction: numerical
(FACEIT in IPDS; Stoe & Cie, 1999)
h = 1112
Tmin = 0.188, Tmax = 0.658k = 99
6492 measured reflectionsl = 1414
1667 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.058Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.139H-atom parameters not refined
S = 1.04 w = 1/[σ2(Fo2) + (0.1099P)2]
where P = (Fo2 + 2Fc2)/3
1667 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 1.36 e Å3
0 restraintsΔρmin = 1.73 e Å3
Crystal data top
C6H4Br2SV = 760.4 (3) Å3
Mr = 267.97Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.6843 (19) ŵ = 10.84 mm1
b = 7.2379 (14) ÅT = 173 K
c = 11.484 (2) Å0.4 × 0.4 × 0.2 mm
β = 109.16 (3)°
Data collection top
Stoe IPDS
diffractometer
1667 independent reflections
Absorption correction: numerical
(FACEIT in IPDS; Stoe & Cie, 1999)
1444 reflections with I > 2σ(I)
Tmin = 0.188, Tmax = 0.658Rint = 0.064
6492 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0580 restraints
wR(F2) = 0.139H-atom parameters not refined
S = 1.04Δρmax = 1.36 e Å3
1667 reflectionsΔρmin = 1.73 e Å3
82 parameters
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.90429 (5)0.69525 (7)0.15399 (5)0.0306 (2)
Br20.75506 (5)0.94572 (7)0.30330 (4)0.0290 (2)
C10.7287 (5)0.7946 (6)0.1647 (4)0.0214 (9)
C20.5999 (5)0.7559 (7)0.0803 (4)0.0225 (9)
H20.60610.68180.01390.027*
C30.4530 (5)0.8068 (6)0.0720 (4)0.0188 (8)
C40.3277 (5)0.7471 (7)0.0213 (4)0.0225 (9)
H40.33050.66950.08730.027*
C50.1970 (6)0.8134 (7)0.0080 (5)0.0307 (11)
H50.10260.78570.06370.037*
C60.2213 (5)0.9216 (7)0.0939 (5)0.0289 (10)
H60.14550.97710.11740.035*
S0.40366 (13)0.94655 (17)0.17497 (12)0.0265 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0220 (3)0.0379 (4)0.0324 (3)0.00528 (18)0.0097 (2)0.0004 (2)
Br20.0268 (3)0.0342 (3)0.0250 (3)0.00466 (18)0.0072 (2)0.00800 (17)
C10.024 (2)0.021 (2)0.0202 (19)0.0009 (16)0.0089 (17)0.0037 (16)
C20.024 (2)0.020 (2)0.024 (2)0.0027 (18)0.0104 (18)0.0016 (17)
C30.024 (2)0.0157 (19)0.0183 (19)0.0008 (15)0.0095 (17)0.0015 (15)
C40.024 (2)0.020 (2)0.024 (2)0.0029 (17)0.0083 (18)0.0041 (17)
C50.020 (2)0.034 (3)0.036 (3)0.0005 (18)0.005 (2)0.006 (2)
C60.022 (2)0.028 (2)0.037 (3)0.0003 (18)0.011 (2)0.003 (2)
S0.0256 (6)0.0287 (6)0.0277 (6)0.0006 (4)0.0121 (5)0.0054 (4)
Geometric parameters (Å, º) top
Br1—C11.887 (5)C4—C51.408 (7)
Br2—C11.878 (5)C4—H40.95
C1—C21.335 (7)C5—C61.362 (8)
C2—C31.442 (6)C5—H50.95
C2—H20.95C6—S1.714 (5)
C3—C41.397 (7)C6—H60.95
C3—S1.738 (4)
C2—C1—Br2124.9 (4)C3—C4—H4123.3
C2—C1—Br1121.3 (4)C5—C4—H4123.3
Br2—C1—Br1113.7 (3)C6—C5—C4112.4 (5)
C1—C2—C3131.4 (4)C6—C5—H5123.8
C1—C2—H2114.3C4—C5—H5123.8
C3—C2—H2114.3C5—C6—S112.6 (4)
C4—C3—C2124.1 (4)C5—C6—H6123.7
C4—C3—S109.8 (3)S—C6—H6123.7
C2—C3—S126.1 (3)C6—S—C391.9 (2)
C3—C4—C5113.3 (4)

Experimental details

Crystal data
Chemical formulaC6H4Br2S
Mr267.97
Crystal system, space groupMonoclinic, P21/c
Temperature (K)173
a, b, c (Å)9.6843 (19), 7.2379 (14), 11.484 (2)
β (°) 109.16 (3)
V3)760.4 (3)
Z4
Radiation typeMo Kα
µ (mm1)10.84
Crystal size (mm)0.4 × 0.4 × 0.2
Data collection
DiffractometerStoe IPDS
diffractometer
Absorption correctionNumerical
(FACEIT in IPDS; Stoe & Cie, 1999)
Tmin, Tmax0.188, 0.658
No. of measured, independent and
observed [I > 2σ(I)] reflections
6492, 1667, 1444
Rint0.064
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.058, 0.139, 1.04
No. of reflections1667
No. of parameters82
H-atom treatmentH-atom parameters not refined
Δρmax, Δρmin (e Å3)1.36, 1.73

Computer programs: EXPOSE in IPDS (Stoe & Cie, 1999), CELL in IPDS (Stoe & Cie, 1999), INTEGRATE in IPDS (Stoe & Cie, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).

 

Acknowledgements

We thank the Fonds der Chemischen Industrie (FCI) and the Deutsche Forschungsgemeinschaft (DFG) for financial support.

References

First citationBeny, J.-P., Dhawan, S. N., Kagan, J. & Sundlass, S. (1982). J. Org. Chem. 47, 2201–2204.  CrossRef CAS Web of Science Google Scholar
First citationBestmann, H. J. & Frey, H. (1980). Liebigs Ann. Chem. pp. 2061–2071.  CrossRef Google Scholar
First citationClément, S., Guyard, L., Knorr, M., Dilsky, S., Strohmann, C. & Arroyo, M. (2007a). J. Organomet. Chem. 692, 839–850.  Google Scholar
First citationClément, S., Guyard, L., Knorr, M., Vilafane, F., Strohmann, C. & Kubicki, M. M. (2007b). Eur. J. Inorg. Chem. pp. 5052–5061.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationHerz, H.-G., Queiroz, M. J. R. P. & Maas, G. (1999). Synthesis, pp. 1013–1016  CSD CrossRef Google Scholar
First citationMukherjee, A. K., Mukherjee (née Mondal), M., De, A. & Bhattacharyya, S. P. (1984). Acta Cryst. C40, 991–992.  Google Scholar
First citationRao, M. L. N., Jadhav, D. N. & Dasgupta, P. (2010). Org. Lett. 12, 2048–2051.  Web of Science CrossRef CAS PubMed Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStoe & Cie (1999). IPDS. Stoe & Cie, Darmstadt, Germany.  Google Scholar
First citationZhang, A., Zheng, X., Fan, J. & Shen, W. (2010). Tetrahedron Lett. 51, 828–831.  Web of Science CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds