Bis(2-thien­yl)acetyl­ene

Abstract

The planar [maximum deviation 0.0066 (4) Å] symmetrical mol­ecule of the title compound, C₁₀H₆S₂, lies across a crystallographic inversion centre. The thio­phene rings are rotationally disordered about the acetyl­ene bond, with the two pseudo inversion-related S atoms in 0.80:0.20 occupancy sites. The C C bond distance is 1.195 (9) Å.

Related literature

For the preparation of the title compound, related diaryl­acetyl­enes and cobalt-containing metallocenes derived from these materials, see: Harrison et al. (1997 ▶); Harcourt et al. (2008 ▶). For recent synthetic organic uses, see: Yu & Rovis (2006 ▶); Geyer et al. (2008 ▶). The metal center employed in an acetyl­ene cyclo­oligomerization may also remain as an integral component of the product, or products, see: Rausch & Genetti (1970 ▶). For spectroscopic data, see: Mio et al. (2002 ▶).

Experimental

Crystal data

• C₁₀H₆S₂

• M _r = 190.29

• Orthorhombic,

• a = 10.6325 (15) Å

• b = 10.8713 (15) Å

• c = 7.5600 (5) Å

• V = 873.85 (18) ų

• Z = 4

• Mo Kα radiation

• μ = 0.54 mm⁻¹

• T = 120 K

• 0.55 × 0.05 × 0.03 mm

Data collection

• Nonius KappaCCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ▶) T _min = 0.755, T _max = 0.984

• 3812 measured reflections

• 849 independent reflections

• 493 reflections with I > 2σ(I)

• R _int = 0.129

Refinement

• R[F ² > 2σ(F ²)] = 0.073

• wR(F ²) = 0.173

• S = 1.08

• 849 reflections

• 58 parameters

• H-atom parameters constrained

• Δρ_max = 0.41 e Å⁻³

• Δρ_min = −0.41 e Å⁻³

Data collection: COLLECT (Nonius, 1998 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

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

supplementary crystallographic information

Comment

Diarylacetylenes are versatile components of metal-mediated cycloaddition reactions. Their relative ease of preparation from palladium catalyzed coupling of aryl iodides to acetylene has ensured their continued use in the development of new synthetic routes, for example, nitrogen containing heterocycles (Yu & Rovis, 2006), and new catalytic reaction methodologies such as alkyne–nitrile cross metathesis (Geyer et al., 2008). The metal center employed in an acetylene cyclooligomerization may also remain as an integral component of the product, or products, as described in the seminal work of Rausch & Genetti (1970). The title compound bis(2-thienyl)acetylene (I) is found to have inversion symmetry coincident with crystallographic symmetry (Fig. 1). However, the two 2-thiophene residues are rotationally disordered about the acetylene bond with the two pseudo-inversion related S atoms having 80/20% occupancy. The C—C triple bond distance is 1.195 (9) Å.

Experimental

The title compound was prepared by Sonogashira coupling of two equivalents of 2-iodothiophene to acetylene under standard conditions (Harrison et al., 1997). Full experimental details (Harcourt et al., 2008) and spectroscopic data (Mio et al., 2002) have been previously published.

Refinement

All H atoms were included in the refinement at calculated positions, in the riding-model approximation, with C—H distances of 0.95 Å. The isotropic displacement parameters for all H atoms were set equal to 1.25U_eq of the carrier atom. The refined site occupancy factors for the disordered atoms (S1, C3, H3) and (S3, C1, H1) of the pseudo-centrosymmetrically related thiophene rings were 0.80 (1), and 0.20 (1) respectively. Structure factor file checks indicate that there is only one listed reflection that is likely to have been affected by the beamstop.

Figures

Fig. 1.

Molecular configuration and atom-numbering scheme for (I) showing inversion symmetry [symmetry code: (a) -x, -y + 1, -z]. Rotationally disordered thiophene S/C atom pairs are S1, C3 (S.O.F. 0.80) and S3, C1 (S.O.F. 0.20). Displacement ellipsoids are drawn at the 50% probability level.

Crystal data

C10H6S2	F(000) = 392
Mr = 190.29	Dx = 1.446 Mg m−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 1041 reflections
a = 10.6325 (15) Å	θ = 1.0–27.5°
b = 10.8713 (15) Å	µ = 0.54 mm−1
c = 7.5600 (5) Å	T = 120 K
V = 873.85 (18) Å3	Needle, colourless
Z = 4	0.55 × 0.05 × 0.03 mm

Data collection

Nonius KappaCCD diffractometer	849 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode	493 reflections with I > 2σ(I)
10 cm confocal mirrors	Rint = 0.129
Detector resolution: 9.091 pixels mm-1	θmax = 26.0°, θmin = 2.7°
φ and ω scans	h = −13→11
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −13→12
Tmin = 0.755, Tmax = 0.984	l = −9→8
3812 measured reflections

Refinement

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)] = 0.073	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.173	H-atom parameters constrained
S = 1.08	w = 1/[σ2(Fo2) + (0.050P)2 + 3.1085P] where P = (Fo2 + 2Fc2)/3
849 reflections	(Δ/σ)max < 0.001
58 parameters	Δρmax = 0.41 e Å−3
0 restraints	Δρmin = −0.41 e Å−3

Special details

Experimental. The minimum and maximum absorption values stated above are those calculated in SHELXL97 from the given crystal dimensions. The ratio of minimum to maximum apparent transmission was determined experimentally as 0.675726.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
S1	0.17278 (13)	0.28773 (15)	0.17139 (19)	0.0303 (6)	0.80
C1	0.17278 (13)	0.28773 (15)	0.17139 (19)	0.0303 (6)	0.20
H1	0.1105	0.2380	0.2263	0.038*	0.20
C2	0.1671 (4)	0.4188 (5)	0.0513 (6)	0.0220 (12)
C3	0.2949 (3)	0.4642 (3)	−0.0126 (4)	0.0291 (9)	0.80
H3	0.3142	0.5342	−0.0827	0.036*	0.80
S3	0.2949 (3)	0.4642 (3)	−0.0126 (4)	0.0291 (9)	0.20
C4	0.3820 (5)	0.3703 (5)	0.0635 (6)	0.0295 (15)
H4	0.4705	0.3749	0.0468	0.037*
C5	0.3285 (4)	0.2786 (5)	0.1572 (6)	0.0271 (13)
H5	0.3757	0.2144	0.2105	0.034*
C6	0.0498 (4)	0.4768 (5)	0.0149 (6)	0.0235 (14)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
S1	0.0283 (8)	0.0314 (11)	0.0311 (8)	0.0002 (8)	−0.0017 (6)	0.0030 (7)
C1	0.0283 (8)	0.0314 (11)	0.0311 (8)	0.0002 (8)	−0.0017 (6)	0.0030 (7)
C2	0.022 (2)	0.023 (3)	0.021 (2)	−0.001 (2)	−0.0019 (19)	0.000 (2)
C3	0.0264 (16)	0.029 (2)	0.0322 (16)	0.0028 (17)	−0.0049 (13)	−0.0064 (15)
S3	0.0264 (16)	0.029 (2)	0.0322 (16)	0.0028 (17)	−0.0049 (13)	−0.0064 (15)
C4	0.021 (2)	0.035 (4)	0.032 (3)	−0.002 (3)	0.003 (2)	−0.008 (3)
C5	0.030 (3)	0.027 (3)	0.025 (2)	0.012 (3)	−0.007 (2)	−0.006 (2)
C6	0.025 (2)	0.021 (4)	0.025 (2)	−0.002 (2)	−0.001 (2)	−0.001 (2)

Geometric parameters (Å, °)

S1—C2	1.691 (5)	C4—C5	1.349 (7)
C2—C6	1.424 (6)	C4—H4	0.95
C2—C3	1.525 (5)	C5—H5	0.95
C3—C4	1.493 (6)	C6—C6i	1.195 (9)
C3—H3	0.95
C6—C2—C3	125.2 (4)	C5—C4—C3	116.4 (4)
C6—C2—S1	120.5 (4)	C5—C4—H4	121.8
C3—C2—S1	114.2 (3)	C3—C4—H4	121.8
C4—C3—C2	102.1 (3)	C4—C5—H5	122.9
C4—C3—H3	128.9	C6i—C6—C2	178.7 (7)
C2—C3—H3	128.9
C6—C2—C3—C4	179.9 (4)	C2—C3—C4—C5	0.8 (5)
S1—C2—C3—C4	−1.1 (4)

Symmetry codes: (i) −x, −y+1, −z.