Photophysical and electrochemical properties of alternating copolymers consisting of 3,4-ethylenedioxythiophene and 4,4′-diphenylamine/3,6-carbazole

ABSTRACT

In the past decades, π-conjugated polymers including polyaniline (PANI), polycarbazole (PCz) and poly(3,4-ethylenedioxythiophene) (PEDOT), have roused much attention and been widely applied in high-performance organic semiconductors on account of their unique electronic, optoelectronic, electrochemical, and mechanical properties. Herein, two kinds of alternating copolymers, poly[(N-(2-ethylhexyl)carbazole-3,6-diyl)-(3,4-ethylenedioxythiophene-2,5-diyl)] (P(3,6-Cz-EDOT)) and poly[(N-(2-ethylhexyl)diphenylamine-4,4′-diyl)-(3,4-ethylenedioxythiophene-2,5-diyl)] (P(4,4′-DPA-EDOT)) were subtly designed and synthesized via direct (hetero)arene polymerization (DHAP) in good yields (up to 88% and 90%, respectively) and high molecular weights (up to 8400 and 24100 Da, respectively). The photophysical, electrochemical, thermal and morphological properties of P(3,6-Cz-EDOT) and P(4,4′-DPA-EDOT) were systematically investigated based on experimental analysis and theoretical simulations. As compared to P(4,4′-DPA-EDOT), P(3,6-Cz-EDOT) exhibited shorter π-conjugation, a higher glass transition temperature (T_g), better thermal stability, more porous morphology and a preferably curved or spiral conformation. Moreover, both P(3,6-Cz-EDOT) and P(4,4′-DPA-EDOT) possessed high specific discharge capacities, indicating their potential applications in solution-processed charge-storage devices.

Graphical abstract

KEYWORDS:

• EDOT-based polymers
• 3, 6-carbzole
• 4,4'ʹ-diphenylamine
• alternating copolymers
• structure-property relationships

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Author contributions

QG and JL conceived the research and supervised the whole work. JZ, XL, and HL prepared materials and characterized the NMR and GPC. QG and XL contributed to the theoretical calculations. LT, HG, and SW contributed to the characterization of the photophysical and electrochemical properties. All authors contributed to the manuscript revision and approved the submitted version.

Qiang Guo

Dr. Qiang Guo is a teacher in Chengdu University of Information Technology. His research interests include design, synthesis, and fabrication of π-conjugated organic materials.

Jincheng Zhang

Mr. Jincheng Zhang is currently a postgraduate student in Chengdu University of Information Technology.

Xiaoyu Li

Dr. Xiaoyu Li is a teacher in Southwest University of Science and Technology.

Hui Liu

Dr. Hui Liu is a teacher in Chengdu University of Information Technology.

Li Tao

Dr. Li Tao is a teacher in Chengdu University of Information Technology.

Heqi Gong

Mr. Heqi Gong is a postgraduate student in Chengdu University of Information Technology.

Shuanghong Wu

Dr. Shuanghong Wu is a professor in University of Electronic Science and Technology of China.

Jie Li

Dr. Jie Li is a professor in Chengdu University of Information Technology. His research interests include design, synthesis, and fabrication of π-conjugated organic materials.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [21801028, 61505015], Department of Science and Technology of Sichuan Province [2019YJ0358, 2020YFG0038, 2017FZ0085].