Polyheterocyclics Polythiophene

Poly (thiophene)s are of particular interest as electfochromic materials owing to their chemical stability, ease of synthesis and processability. For the most part, current research has been focused on composites, blends and copolymer formations of several conjugated polyheterocyclics, polythiophene and its derivatives, especially PEIX)T. In one example, poly(3,4-ethylenedioxythiophene) (PEDOT)/poly(2-acrylamido-2-methyl-l-propanesulfonate) (PAMPS) composite films were prepared by Sonmez et al. for alternative electrochromic applications [50]. Thin composite films comprised of PEDOT/PAMPS were reported to switch rapidly between oxidized and neufial states, in less than 0.4 s, with an initial optical contrast of 76% at A.max. 615 nm. Nanostructured blends of electrochromic polymers such as polypyrrole and poly(3,4-ethylenedioxythiophene) were developed via self-assembly by Inganas etal. for application as an electrochromic window [26]. Uniir etal. developed a graft-type electrochromic copolymer of polythiophene and polytetrahydrofuran for use in elecfiochromic devices [51]. Two EDOT-based copolymers, poly[(3,4-ethylenedioxythiophene)-aZ/-(2,5-dioctyloxyphenylene)] and poly[(3,4-ethylenedioxythiophene)-aft-(9,9 -dioctylfluorene)] were developed by Aubert et al. as other candidates for electrochromic device development [52],... 

Polythiophenes (PTs) have received a great deal of attention due to their electrical properties, environmental stability in doped and undoped states, non-linear optical properties, and highly reversible redox switching [1]. Thiophene possesses a rich synthetic flexibility, allowing for the use of several polymerization methods and the incorporation of various side chain functionalities. Thus, it is of no great surprise that PTs have become the most widely studied of all conjugated polyheterocycles [184]. 

CLASS Polyheterocyclics conjugated conducting polymers STRUCTURE Polythiophene exists in two structures (Aromatic)... 

As an example, we discuss a structural study, by the Rietveld [10] method, of neutral poly thiophene [11]. This polymer is, sofar, the most ordered polyheterocycle, even though no oriented films have been obtained up to now, and so the only available samples are thermally annealed powders. Interestingly, aside from the expected (and found) co-planarity between adjacent rings, the detected 3-D order can be interpreted in terms of a discrete number of preferred arrangements, each of them shifted with respect to another along the chain axis, and co-present in the crystallites. This hypothesis accounts for the relative doping ease of polythiophene. 

Among the organic semiconductor classes used in OFETs, oligo- and polythiophenes are among the most extensively investigated due to their chemical/electrochemical stability and ready functionalization [10, 11] The first report of a polyheterocycle-based FET utilized a polythiophene [12], with... 

The first mention of polythiophenes as potential conducting polymers can be found in the literature in 1967. A. G. Davies and coauthors investigated the acid catalyzed polymerization of furan, pyrrole, and thiophene hetero-cycles. Although this polymerization reaction was known before, several new and interesting facts could be elucidated. Besides the confirmation of the cyclic structure of the polymer units (instead of ring opened), the electric conductivity was investigated. In contrast to the already known types of electronically conducting polymers (polyaniline and polypyrrole, see Chapter 1), the conductivity of all polyheterocycles in Armour s paper, isolated as trichloro- or trifluoroacetates (triflate), is ionic. In the case of the polythiophene, ion pairs formed by the reaction of polythiophene with trifluoro acetic acid dissociated in methylene chloride solution to the protonated polymer and triflate anions. The polythiophene triflate decomposed at relatively low temperatures (60°C-80°C). ... 

Polythiophene is a conjugated polyheterocycle in which backbone stmcture differs markedly firom those of PDA or Polyacetylene. In contrast to PDA these polymers are easily dopable. A common way for describing the doped state is to use the concept of... 

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