Poly 3-Alkylthiophenes

In all cases of electrochemicaHy or chemically polymerized unsubstituted polypyrrole, the final polymer is intractable in both the conducting and insulating forms. In contrast, a broad number of substituted polythiophenes have been found to be processible both from solution and in the melt. The most studied of these systems ate the poly(3-alkylthiophenes) (P3AT). 

In the field of soluble conducting polymers new data have been published on poly(3-alkylthiophenes " l They show that the solubility of undoped polymers increases with increasing chain length of the substituent in the order n-butyl > ethyl methyl. But, on the other hand, it has turned out that in the doped state the electro-chemically synthesized polymers cannot be dissolved in reasonable concentrations In a very recent paper Feldhues et al. have reported that some poly(3-alkoxythio-phenes) electropolymerized under special experimental conditions are completely soluble in dipolar aprotic solvents in both the undoped and doped states. The molecular weights were determined in the undoped state by a combination of gel-permeation chromatography (GPC), mass spectroscopy and UV/VIS spectroscopy. It was established that the usual chain length of soluble poly(3-methoxthythiophene) consists of six monomer units. 

Yoshino, K. Takahashi, H. Muro, K. Ohmori, Y. Sugimoto, R. 1991. Optically controlled characteristics of Schottky gated poly(3-alkylthiophene) field effect transistor. J. Appl. Phys. 70 5035-5039. 

Deen, M. Kazemeini, M. Haddara, Y. Yu, J. Vamvounis, G Holdcroft, S. Woods, W. 2004. Electrical characterization of polymer-based FETs fabricated by spin-coating poly(3-alkylthiophene)s. IEEE Trans. Electronic Dev. 51 1892-1901. 

Jaczewska, J. Raptis, I. Budkowski, A. Goustouridis, D. Raczkowska, J. Sanopoulou, M. Pamula, E. Bemasik, A. Rysz, J., Swelling of poly(3 alkylthiophene) films exposed to solvent vapors and humidity Evaluation of solubility parameters, Synth. Met. 2007, 157, 726 732... 

FI Tomozawa, D Braun, SD Phillips, AJ Fleeger, and FI Kroemer, Metal-polymer Schottky barriers on cast films of soluble poly(3-alkylthiophenes), Synth. Met., 22 63-69, 1987. 

M Uchida, Y Ohmori, C Morishima, and K Yoshino, Visible and blue electroluminescent diodes utilizing poly(3-alkylthiophene)s and poly(alkylfluorene)s, Synth. Met., 55-57 4168-4173, 1993. 

Bolognesi and coworkers [481-483] reported the Ni-initiated polymerization of 2,5-diiodothiophenes yielding poly(3-alkylthiophene)s 397-399, containing a methoxy group at the end of the alkyl chain (Scheme 2.62). Small shifts in EL of polymer 399 to higher energies... 

McCullough Method of Preparation of Regioregular HT Poly(3-Alkylthiophenes) (Chart 2.162)... 

Ni-Catalyzed preparation of regioregular HT poly(3-alkylthiophenes) (HT-388) from 2,5-dibromoalkylthiophenes (389) and Rieke zinc (Zn ) (Chart 2.164). 

F. Chen, P.G. Mehta, L. Takiff, and R.D. McCullough, Improved electroluminescence performance of poly(3-alkylthiophenes) having a high head-to-tail (HT) ratio, J. Mater. Chem., 6 1763— 1766, 1996. 

M. Leclerc, F.M. Diaz, and G. Wegner, Structural analysis of poly(3-alkylthiophenes), Makromol. Chem., 190 3105-3116, 1989. 

R.D. McCullough and R.D. Lowe, Enhanced electrical conductivity in regioselectively synthesized poly(3-alkylthiophenes), J. Chem. Soc., Chem. Commun. 70-72, 1992. 

R.S. Loewe, S.M. Khersonsky, and R.D. McCullough, A simple method to prepare head-to-tail coupled, regioregular poly(3-alkylthiophenes) using Grignard metathesis, Adv. Mater., 11 250-253, 1999. 

R.S. Loewe, P.C. Ewbank, J. Liu, L. Zhai, and R.D. McCullough, Regioregular, head-to-tail coupled poly(3-alkylthiophenes) made easy but the GRIM method investigation of the reaction and the origin of regioselectivity, Macromolecules, 34 4324-4333, 2001. 

T.-A. Chen, X. Wu, and R.D. Rieke, Regiocontrolled synthesis of poly(3-alkylthiophenes) mediated by Rieke zinc their characterization and solid-state properties, J. Am. Chem. Soc., 117 233— 244, 1995. 

Y. Ohmori, M. Uchida, K. Muro, and K. Yoshino, Visible-light electroluminescent diodes utilizing poly(3-alkylthiophenes), Jpn. J. Appl. Phys., Part 2, 30 L1938-L1940, 1991. 

A. Bolognesi, W. Porzio, G. Bajo, G. Zannoni, and L. Fanning, Highly regioregular poly (3-alkylthiophenes) a new synthetic route and characterization of the resulting polymers, Acta Polym., 50 151-155, 1999. 

A. Bolognesi, G. Bajo, J. Paloheimo, T. Ostergard, and H. Stubb, Polarized electroluminescence from an oriented poly(3-alkylthiophene) Langmuir-Blodgett structure, Adv. Mater., 9 121-124,1997. 

A Bolognesi, C Botta, and M Martinelli, Oriented poly(3-alkylthiophene) films absorption, photoluminescence and electroluminescence behaviour, Synth. Met., 121 1279-1280, 2001. 

S Nagamatsu, W Takashima, K Kaneto, Y Yoshida, N Tanigaki, K Yase, and K Omote, Backbone arrangement in friction-transferred regioregular poly(3-alkylthiophene)s, Macro molecules, 36 5252-5257, 2003. 

Poly(3-alkylsulfonate thiophene)s, 23 717 Poly(3-alkylthiophenes) (P3ATs) conducting, 7 517 stability, 7 536... 

Fig. 1 Building units of conducting polymers, (1) polyacetylene (PA) (2) polypyrrole (PPy), polythiophene (PTh), polyfurane (PFu) (3) polyphenylene (PP) (4) polyaniline (PANI) 5 polyindole (PIND) (6) polycarbazole (PCaz) (7) polyazulene (Paz) (8) polynaphthalene (PNa) (9) polyanthracene (PAnth) (10) polypyrene (PPyr) (11) polyfluorene (PFiu) (12) poly(isothionaphthalene) (PITN) (13) poly(dithienothiophene) (14) poly(thienopyrrole) (15) poly(dithienylbenzene) (1G) poly(3-alkylthiophene) (17) poly(phenylene vinylene) (18) poly(bipyrrole) (PBPy), poly(bithiophene) (PBT) (19) poly(phenylenesulfide) (20) 4-poly(thienothiophene) (21) poly(thienyl vinylene), poly(furane vinylene) (22) poly(ethylenedioxythiophene) (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...

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