Thiophenes 3,4-ethylenedioxythiophene

This is a very common method for the preparation of graphene/conjugated polymer nanocomposites. In a typical synthetic procedure, surface-modified graphene or GO can be dispersed in acidic water and /or surfactant solution followed by the addition of monomer. It was then stirred obeying a certain conditions to disperse filler in the solvent and monomer homogeneously. Finally, the initiator (generally peroxides are used as initiator) is added to initiate the polymerization reaction at a certain temperature. Aniline, pyrrole, thiophene, 3,4-ethylenedioxythiophene, etc. can be polymerized by this method [73-80]. 

Thiophenes 81a and 81b, which bear carboxylic acid functionalities, have been mercurated using a variety of mercury salts, including Hg(OAc)2 and Hg(OCOCF3)2. When Hg(OAc)2 is employed, these reactions afford a mixture of monomercurated 82a and 82b and dimercurated products 83a and 83b (Equation (32)).101 Dimercuration is also observed when 3,4-ethylenedioxythiophene 84 is treated with Hg(OAc)2 to form 85 (Equation (33)).102... 

Other thiophene-thiophene-5,5-dioxide copolymers were reported by Berlin et al. [544], who synthesized copolymers 443 and 444 with an alternating electron acceptor thiophene-5,5-dioxide unit and donor ethylenedioxythiophene (EDOT) units (Chart 2.107). The polymers absorbed at 535 nm (Eg = 2.3 eV) in chloroform solution and in films (which is consistent with their electrochemistry Eox 0.40-0.50 V, Emd -1.75-1.8 V AE 2.2-2.25 V) and emitted at 650 nm (<1> M (film) 1%). Such a high band gap (which exceeds that in PEDOT... 

Scheme 4 Proposed stacking structure. The plane-to-plane distance d for the polymer shown in No. 19 is about 3.8 A [93-95], which is somewhat shorter than the d value (about 3.85 A) reported for head-to-tail-type poly(3-alkylthiophene) HT-P3RTh [128,129] and somewhat longer than the d values (3.6-3.65 A) observed with head-to-head-type poly(4-alkylthiazole-2,5-diyl) [124,129,130] and the charge-transfer-type copolymer of thiophene and 4-alkylthi-azole [131]. Poly(ethylenedioxythiophene) gives a similar d value (3.8 A) [132]. The existence of S in the aromatic ring seems to make the distance d longer...

Nagarajan R, Bruno FF, Samuelson LA, Kumar J (2004) Thiophene oligomer as a redox mediator for the biocatalytic synthesis of poly(3,4-ethylenedioxythiophene) [PEDOT]. Polym Prepr 45 195-196... 

Sotzing [2] prepared intrinsically conducting water-borne dispersions of poly (thieno[3,4-b]thiophene) homopolymer, (II), and copolymers of thieno[3,4-b] thiophene and 3,4-ethylenedioxythiophene, (111), for electroactive applications including electrochromic displays, optically transparent electrodes, and antistatic coatings. 

Turbiez, M., Frere, P., Blanchard, P., and Roncali, J., Mixed 7t-conjugated oligomers of thiophene and 3,4-ethylenedioxythiophene (EDOT), Tetrahedron Lett., 41, 5521, 2000. 

A linear phthalocyanine containing polyesters 46 has been described [128,129], Recently, a linear polymeric phthalocyanine 47 prepared in a multistep synthesis with an iptycene architecture was briefly described [130]. At first two differently substituted l,3-dihydro-l,3-diiminoisoindolenines were statistically reacted. In the mixture of phthalocyanines obtained, the ethylenedioxythiophene part is introduced and the bis(ethyleneoxythiophene) oppositely substituted phthalocyanine was isolated by flash chromatography. Afterwards the thiophene parts in the phthalocyanine were electrochemically polymerized to obtain 47. 

Figure 28.3. Structural formulas of several electron-conducting polymers (a) frans-poly(acetylene), (b) cw-poly(acetylene), (c) poly(p-phenylene), (d) polyanUine (PAni), (e) poly(n-methylaniline) (PNMA), (f) polypyrrole (PPy), (g) polythiophene (PTh), (i) poly(3,4-ethylenedioxythiophene) (PEDOT), (j) poly(3-(4-fluorophenyl)thiophene) (PFPT), (k) poly(cyclopenta[2,l-b 3,4-dithiophen-4-one]) (PcDT), and (m) Mg polyporphine.

Early progress in polythiophene chemistry was achieved by the synthesis of mono- and dialkoxy-substituted thiophene derivatives developed by Leclerc [6] and industrial scientists at Hoechst AG [7-9]. However, most polymers of mono- and dialkoxythiophenes exhibited low conductivity in the oxidized, doped state. A breakthrough in this area was the synthesis of polymers of the bicyclic 3,4-ethylenedioxythiophene (EDT or EDOT) and its derivatives—electrochemically polymerized by Heinze et al. and chemically polymerized by Jonas et al. of the Bayer Corporate Research Laboratories [10,11]. In contrast to the nonbicyclic polymers of mono- and dialkoxythiophenes, PEDT has a very stable and highly conductive cationic doped state. The low HOMO-LUMO bandgap of conductive PEDT allowed the formation of a tremendously stable, highly conductive ICP [12]. Technical use and commercialization quickly followed today ICPs based on PEDT are commercially available in multiton quantities. 

Recently, Turbiez et al. [27] reported a poly(3,4-ethylenedioxythiophene) (PEDOT) like polymer, poly(3,6-dimethoxythieno[3,2-h]thiophene), which exhibited a discernible vibronic fine structure with max at 592 nm (Figure 11.7) and a band-edge gap of 1.65 eV. The electrochemically synthesized polymer was reported as pale blue in the oxidized form, while the spectrum of the oxidized polymer remained unchanged even after 1 week, indicative of a potential transparent semiconductor like PEDOT. 

Turbiez, M., et al. 2005. Poly(3,6-dimethoxy-thieno[3,2-l ]thiophene) A possible alternative to poly(3,4-ethylenedioxythiophene) (PEDOT). / Chem Soc Chem Commun 1161. 

Seshadri, V., L. Wu, and G.A. Sotzing. 2003. Gonjugated polymers via electrochemical polymerization of thieno[3,4-1 ]thiophene (T34bT) and 3,4-ethylenedioxythiophene (EDOT). Langmuir 19 9479. 

Berlin, A., et al. 2004. New low-gap polymers from 3,4-ethylenedioxythiophene-bis-substituted electron-poor thiophenes. The roles of thiophene, donor-acceptor alternation, and copolymerization in intrinsic conductivity. Chem Mater 16 3667. 

Alkylation of Thiophene Poly(3,4-Ethylenedioxythiophene) and Sulfur Derivatives Reduced Bandgap Polymers Based on Chalcogen 3,4-Substituted Thiophenes Structural Modifications of EDOT Functionalized EDOT Derivatives... 

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