2,2′:5′,2′′-Terthiophene

2,2′:5′,2′′-Terthiophene (TTh) may be prepared by nickel catalysed coupling reaction of grignard′s reagent derived from 2-bromothiophene and magnesium. It generates singlet oxygen. In nature, it is found in the floral extract of Tagetes minuta and Echinops grijisii. It is known to be toxic to mosquitoes. It also exihibits antifungal activity.

3T can be combined with 3,4-ethylenedioxythiophene (EDOT) in a tetrabutylammonium perchlorate solution for use as an electrochromic copolymer for a wide range of applications like photovoltaics and polymer light emitting diodes (LEDs). It can also be used to form metal-organic based thin films with metals like aluminum, silver, and calcium which can potentially be used for optoelectronics based applications.

Electrochemical copolymerization of carbazole and TTh in sodium perchlorate/acetonitrile was reported. Electrochromic copolymer based on TTh and 3, 4-ethylenedioxythiophene has been reported. TTh acts as a monomer precursor for polythiophene and as a dopant for polycarbonate. It may function as a photosensitizer.