Thiophene groups polythiophene

Polythiophene can be synthesized by electrochemical polymerization or chemical oxidation of the monomer. A large number of substituted polythiophenes have been prepared, with the properties of the polymer depending on the nature of the substituent group. Oligomers of polythiophene such as (a-sexithienyl thiophene) can be prepared by oxidative linking of smaller thiophene units (33). These oligomers can be sublimed in vacuum to create polymer thin films for use in organic-based transistors. 

M. Pomerantz, H. Yang, and Y. Cheng, Poly(alkyl thiophene-3-carboxylates). Synthesis and characterization of polythiophenes with a carbonyl group directly attached to the ring, Macromolecules, 28 5706-5708, 1995. 

Anodic oxidation of a-trimethylsilylated thiophene derivatives in nitrobenzene results in desilylation and formation of polythiophenes (equation 4), which have higher conductivity than those prepared from unsilylated thiophenes7-9. The silyl group increases the regioselectivity of carbon-carbon bond formation since the silyl group is an excellent... 

Some fundamental aspects of polythiophene preparation and chemistry have been investigated. Solution processing of a polythiophene having ester groups has been performed, which after ester cleavage and decarboxylation gave new access to the parent thiophene polymer <07MAC6012>. The mechanism of the photoinduced polymerization of thiophene... 

Another example of the anodic oxidation of 7r-systems having a silyl group at the a-position is the electrochemical oxidation of 2,5-bis(trimethylsilyl)thiophene, resulting in the elimination of the trimethylsilyl group to produce polythiophene. Polythiophenes obtained by this method have high conductivity [156]. 

A second major class of emissive polymer is based on polythiophene [8], Again, substitution in this case at the -3- position of the thiophene ring is used to solubilize the polymer and to time the emission wavelength [9]. Other heterocyclic conjugated polymers are represented by polypyridine [10] and polypyridi-nevinylene [11]. Since each of these contains electron-deficient aromatic groups, they lend to be better electron transporters than their phenylene analogs. They emit primarily in the blue. 

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