Terthiophene

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Terthiophene

IUPAC name	2,2':5',2"-terthiophene
Other names	α-Terthienyl 2,5-Di(2-thienyl)thiophene
Identifiers
CAS number	[1081-34-1]
RTECS number	WZ9717750
Properties
Molecular formula	C₁₂H₈S₃
Molar mass	248.39 g/mol
Appearance	pale yellow solid
Density	? g/cm³, ?
Melting point	93-95 °C
Solubility in water	insoluble
Hazards
Main hazards	flammable
S-phrases	22-24/25
Related compounds
Related compounds	Thiophene polythiophene
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Terthiophene is the organic compound with the formula [C₄H₃S]₂C₄H₂S. It is an oligomer of the heterocycle thiophene, a shorter oligomer is dithienyl, and the parent polymer is polythiophene. In the most common isomer of terthiophene, two thienyl groups are connected via their 2 positions to a central thiophene, also at the carbon atoms flanking the sulfur.

[edit] Preparation of terthiophene

Terthiophene is prepared by the nickel- or palladium-catalysed coupling reaction of 2,5-dibromothiophene with the Grignard reagent derived from 2-bromothiophene.^[1]

[edit] Properties and applications

This isomer is a pigment in African marigolds (Tagetes spp.) and exhibits some biological activity because it sensitizes the formation of singlet oxygen, which is often lethal.^[2] A variety of terthiophenes occur naturally, including 5,5''-dichloro-α-terthiophene, 5-chloro-α-terthiophene, 5-acetyl α-terthiophene, and 5-carboxyl bithiophene.^[3]

Terthiophene has been employed as building block for the organic semi-conductor polythiophene.

[edit] References

^ Smeets, B. J. J.; Meijer, R. H.; Meuldijk, J.; Vekemans, J. A. J. M.; Hulshof, L. A. "Process Design and Scale-Up of the Synthesis of 2,2':5',2-Terthienyl" Organic Process Research & Development (2003), volume 7, pages 10-16.
^ Ciofalo, Maurizio; Ponterini, Glauco. Generation of singlet oxygen by 2,2':5',2"-terthiophene and some of its derivatives. Journal of Photochemistry and Photobiology, A: Chemistry (1994), 83(1), 1-6. CODEN: JPPCEJ ISSN:1010-6030.
^ Liu, Y.; Ye, M.; Guo, H.-Z.; Zhao, Y.-Y.; Guo, D.-A. "New thiophenes from Echinops grijisii" Journal of Asian Natural Products Research (2002), volume 4, pages 175-178. JANRFI ISSN:1028-6020.