Synthesis of Poly thiophene

Linear Polymer with Chiral Units 9.4.2.1 Synthesis of Poly (thiophene) 11724a... 

Shi et al. [70] were the first to demonstrate the use of an air and moisture stable ionic liquid, [C4mim][PF,s], for the electrochemical synthesis of poly(thiophene), grown onto a platinum working electrode by potentiodynamic, constant potential or constant current techniques. The use of growth potentials between 1.7 and 1.9 V (vs. Ag/AgCl) reportedly gave smooth, blue-green electroactive films, whereas potentials above 2 V resulted in film destruction by overoxidation. 

Several mechanisms have been proposed for both electrochemical and chemical oxidative synthesis of poly thiophenes. The proposed mechanisms are similar to those proposed for polypyrrole formation. The first step of the polymerization is the oxidation of the thiophene monomer to a cation radical. The subsequent steps are controversial. There are several possibilities. The cation radical can couple with another cation radical or with a neutral species. Alternatively, the cation radical can deprotonate to form a neutral radical. This radical can then couple with another radical or with a neutral species. Several of these possibilities are discussed below. 

Zaman, B.M., and D.R Perepichka. 2005. A new simple synthesis of poly(thiophene-methine)s. Chem Commun 4187-4189. 

T. Endo, Y. Takeoka, M. Rikukawa and K. Sanui. Regiocontrolled synthesis of poly(thiophene) derivatives with fluoroalkyl side-chains. Synth. Met. 135-136, 333-334 (2003). 

G. Dian, G. Barbey and B. Decroix, Electrochemical synthesis of poly thiophenes and poly selenophenes, Synth. Met., 13, 281-289 (1986). 

Fig. 60. Synthesis of poly(thiophene methine)s add-catalyzed polymerization of thiophene and an aldehyde.

Thiophene in Conducting Polymers Synthesis of Poly(thiophene)s and Other Conjugated Polymers Containing Thiophenes, for Application in Polymer Solar Cells. 203... 

Livi F, Carle JE, Bundgaard E (2014) Thiophene in conducting polymers synthesis of poly (thiophene)s and other conjugated polymers containing thiophenes, for application in polymer solar cells. Top Heterocycl Chem. doi 10.1007/7081 2014 128... 

Thiophene in Conducting Polymers Synthesis of Poly(thiophene)s and Other... 

Poly (thiophenes) The chemical synthesis of poly(thiophene) represents a typical Condensation polymerization, employing a Ni catalyst ... 

The wide variety of coupling methods adapted from organic synthesis to condensation polymerization of just one CP can be appreciated from Fig. 5-12. for poly(pheny-lene). Typical condensations and eliminations adapted to syntheses of such CPs as poly(phenylene) and poly(phenylene vinylene) (P(PV)) are illustrated in Fig. 5-13. Fig. 5-14 shows the variety of precursor routes available to P(PV). More recently, the Yu group [86] has demonstrated application of Pd-catalyzed Stille and Heck reactions to the synthesis of poly(thiophene) (P(T)) derivatives (cf. Fig. 5-15. Besides the Grignard couplings such as shown in Eq. 1.6, Chapter 1, P(T) s can also be prepared via a variety of other procedures, such as Friedel-Crafts alkylation [87], and direct oxidation with FeClj as for P(Py) above. 

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