Reactive regioregular oligothiophenes and polythiophenes with Zincke salt structure: Synthesis, reactions, and chemical properties. Issue 4 (22nd November 2013)

• Record Type: Journal Article
• Authors: Yamaguchi, Isao; Tsuse, Yukako
• Is Part Of: Journal of polymer science. Volume 52:Issue 4(2014:Feb.)
• Page Start: 481
• Page End: 492
• Publication Date: 2013-11-22
• Subjects: 547
• DOI: 10.1002/pola.27019
• Languages: English
• ISSNs: 0887-624X

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>Polythiophenes with reactive Zincke salt structure, <bold>P4ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold> and <bold>P5ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold>, were synthesized by the oxidation polymerization of oligothiophenes, such as 3'‐(4‐<italic>N</italic>‐(2, 4‐dinitrophenyl)pyridinium chloride)−2, 2':5', 2'';5'', 2'''‐quarterthiophene (<bold>4ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)</bold>) and 4''‐(4‐<italic>N</italic>‐(2, 4‐dinitrophenyl)pyridinium chloride)−2, 2';5', 2'';5'', 2''';5''', 2''''‐quinquethiophene (<bold>5ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)</bold>), with iron(III) chloride. The reaction of <bold>P5ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold> with R‐NH<sub>2</sub> [R = <italic>n</italic>‐hexyl (Hex) and phenyl (Ph)] substituted the 2, 4‐dinitrophenyl group into the R group with the elimination of 2, 4‐dinitroaniline to yield <bold>P5ThPy<sup>+</sup>R(Cl<sup>−</sup>)</bold>. Similarly, model compounds, <bold>4ThPy<sup>+</sup>R(Cl<sup>−</sup>)</bold> and <bold>5ThPy<sup>+</sup>R(Cl<sup>−</sup>)</bold> (R = Hex and Ph), were also synthesized. In contrast to the photoluminescent <bold>4ThPy</bold> and <bold>5ThPy</bold>, the compounds <bold>P4ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold>, <bold>P5ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold>, and <bold>P5ThPy<sup>+</sup>R(Cl<sup>−</sup>)</bold> showed no photoluminescence because their internal pyridinium rings acted as quenchers. Cyclic voltammetry measurements suggested that <bold>P4ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold>, <bold>P5ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold>, and <bold>P5ThPy<sup>+</sup>R(Cl<sup>−</sup>)</bold> received an electrochemical reduction of the pyridinium and 2, 4‐dinitrophenyl groups and oxidation of the polymer backbone. <bold>P4ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold> and <bold>P5ThPy<sup>+</sup>DNP(Cl<sup>−</sup>)‐a</bold> were electrically conductive (<italic>ρ</italic> = 3.0 × 10<bold><sup>−</sup></bold><sup>6</sup> S cm<bold><sup>−</sup></bold><sup>1</sup> and 2.1 × 10<bold><sup>−</sup></bold><sup>6</sup> S cm<bold><sup>−</sup></bold><sup>1</sup>, respectively) in the nondoped state. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. <bold>2014</bold>, <italic>52</italic>, 481–492</p> </abstract>