2,2′-Bithiophene is the organic compound. It is a colorless solid, although commercial samples are often greenish.[3] It is the most common of the three isomers with formula (C4H3S)2. The other two isomers have the connectivity 2,3′- and 3,3′-. The compound is typically prepared by cross-coupling starting from 2-halothiophenes.

2,2'-Bithiophene
Names
Preferred IUPAC name
2,2′-Bithiophene
Other names
2,2′-Bisthiophene, 2,2′-dithienyl, 2,2′-bithienyl, 2-(2-thienyl)thiophene
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.007.062 Edit this at Wikidata
EC Number
  • 207-767-2
UNII
  • InChI=1S/C8H6S2/c1-3-7(9-5-1)8-4-2-6-10-8/h1-6H
    Key: OHZAHWOAMVVGEL-UHFFFAOYSA-N
  • InChI=1/C8H6S2/c1-3-7(9-5-1)8-4-2-6-10-8/h1-6H
    Key: OHZAHWOAMVVGEL-UHFFFAOYAB
  • c1cc(sc1)c2cccs2
Properties
C8H6S2
Molar mass 166.26 g·mol−1
Appearance Colorless crystals
Density 1.44 g/cm3[1]
Melting point 31.1 °C (88.0 °F; 304.2 K)[2]
Boiling point 260 °C (500 °F; 533 K)[2]
Structure[1]
Monoclinic
P21/c
a = 7.873 A, b = 5.771 A, c = 8.813 A
α = 90°, β = 107.07°, γ = 90°
2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

X-ray crystallography shows that the two rings are coplanar,[3] unlike the situation for biphenyl.

Occurrence

edit

A number of bi- as well as terthiophenes exist naturally, invariably with substituents at the positions flanking sulfur. In terms of the biosynthesis, bithiophenes are proposed to be derived from polyacetylenic precursors, which in turn are the products of dehydrogenation of oleic acid. According to some hypotheses, these polyalkynes form labile 1,2-dithiins via a reaction with H2S2 or its equivalent.[4]

References

edit
  1. ^ a b Pelletier, M.; Brisse, F. (1994). "Bithiophene at 133 K". Acta Crystallographica Section C Crystal Structure Communications. 50 (12): 1942–1945. doi:10.1107/S010827019301011X.
  2. ^ a b Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. p. 3.58. ISBN 9781498754293.
  3. ^ a b Chaloner, P. A.; Gunatunga, S. R.; Hitchcock, P. B. (1994). "Redetermination of 2,2′-bithiophene". Acta Crystallographica C. C50 (12): 1941–2. doi:10.1107/S0108270194001149.
  4. ^ Kagan, J. (1991). "Naturally Occurring Di- and Trithiophenes. In: Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products". Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products. Vol. 56. pp. 87–169. doi:10.1007/978-3-7091-9084-5_2. ISBN 978-3-7091-9086-9. PMID 2050313.