Atom-economical Synthesis and Characterization of Poly(oxindolidene thienylene vinylene) Based on Aldol Polycondensation Reaction

It is known that π-conjugated polymers can be easily synthesized using monomers which possess metals or halogen atoms as well as transition-metal catalysts. However, in the polymer materials synthesized by such reactions, small amounts of halogens and transition-metal-catalysts remain, often negativ...

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Bibliographic Details
Main Authors: Shingo Sato, Po-Shen Lin, Wei-Ni Wu, Cheng-Liang Liu, Tomoya Higashihara
Format: Article
Language:English
Published: MDPI AG 2020-03-01
Series:Catalysts
Subjects:
Online Access:https://www.mdpi.com/2073-4344/10/4/364
Description
Summary:It is known that π-conjugated polymers can be easily synthesized using monomers which possess metals or halogen atoms as well as transition-metal catalysts. However, in the polymer materials synthesized by such reactions, small amounts of halogens and transition-metal-catalysts remain, often negatively affecting their optoelectronic device performances. Herein, we report a new polycondensation method based on the aldol condensation reaction utilizing the intramolecular resonance effect of the anionic monomer through π-conjugation. We have designed a novel AB type monomer to synthesize the semiconducting poly(oxindolidene thienylene vinylene) (POTV) using the proposed system. Indeed, the polymerization readily proceeded by adding 5-nitro-2-thiophenecarbaldehyde as an initiator after the α-proton abstraction of the oxindole group by the reaction of the monomer precursor with lithium hexamethylsilazide (LiHMDS)/12-crown-4. As a result, the objective POTV with <i>M</i><sub>n</sub> = 3700 and <i>Ð</i><sub>M</sub> = 1.47 could be obtained with a good yield (65%). In addition, an organic field effect transistor (OFET) was based on POTV exhibited p-type characteristics, with a hole mobility of 2.24 × 10<sup>−4</sup> cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup>.
ISSN:2073-4344