Abstract In this study, two novel electrochromic copolymers (CoP1.3 and CoP1.5) were synthesized via electrochemical methods and characterized. The comonomers used in the synthesis were 3,4-ethylenedioxythiophene (EDOT) and a carbazole comprising monomer; 9-(2-(4-(Phenyldiazenyl) phenoxy) ethyl)-3,6-di(thiophen-2-yl)-9H-carbazole (M1). Carbazole containing monomer (M1) and EDOT were combined with two different comonomer feed ratios, 1: 3 and 1: 5 respectively in order to investigate the effect of increasing EDOT amount on electrochemical, spectroelectrochemical and electrochromic behaviors. The electrochemical and spectroelectrochemical characterizations of the electrochemically obtained copolymers were performed by cyclic voltammetry (CV) and UV–vis-NIR spectrophotometry. Both copolymers exhibited p-type doping with reversible oxidation potentials reported at 0.23 V/0.93 V for CoP1.3 and 0.30 V/0.98 V for CoP1.5. The difference between these oxidation potentials could be dedicated to the difference in electron density in the copolymer chains. Optical band gap values were calculated from neutral state absorptions as 1.21 eV and 1.18 eV for CoP1.3 and CoP1.5, respectively. Due to the higher EDOT amount in the copolymer backbone, the band gap for CoP1.5 is lower than that of CoP1.3. Both CoP1.3 and CoP1.5 exhibited multichromic behavior with different colors in the neutral and oxidized states. While both copolymers (CoP1.3 and CoP1.5) exhibited purple color in the neutral states, the colors turned to blue colors upon applied potentials. Optical contrast values were calculated as 31 % (at 555 nm), 55 % (at 1050 nm) and 38 % (at 1240 nm) for CoP1.3 and 34 % (at 565 nm), 25 % (at 975 nm) and 45 % (at 1170 nm) for CoP1.5. As a result of electrochromic switching studies, switching times (oxidation) were calculated as 2.5 s, 1.7 s, 1.9 s for CoP1.3 and 1.9 s, 1.8 s, 2.7 s for CoP1.5. Furthermore, addition of EDOT unit into copolymer backbone resulted in the obvious improvements in electrochemical, optical, electrochromic and kinetic properties. Copolymers exhibited full visible absorption with red-shifted neutral state absorption, lower optical band gap values compared to those of homopolymers.

中文翻译：

---

通过与 3,4-乙撑二氧噻吩 (EDOT) 共聚提高含咔唑单体的电化学和电致变色性能

摘要 在本研究中，通过电化学方法合成了两种新型电致变色共聚物（CoP1.3 和 CoP1.5）并对其进行了表征。合成中使用的共聚单体是3,4-乙撑二氧噻吩（EDOT）和含咔唑的单体；9-(2-(4-(苯基二氮烯基)苯氧基)乙基)-3,6-二(噻吩-2-基)-9H-咔唑(M1)。为了研究增加 EDOT 量对电化学、光谱电化学和电致变色行为的影响，将含咔唑单体 (M1) 和 EDOT 与两种不同的共聚单体进料比分别为 1:3 和 1:5。通过循环伏安法 (CV) 和 UV-vis-NIR 分光光度法对电化学获得的共聚物进行电化学和光谱电化学表征。两种共聚物都表现出 p 型掺杂，可逆氧化电位报告为 CoP1.3 为 0.23 V/0.93 V，CoP1.5 为 0.30 V/0.98 V。这些氧化电位之间的差异可以归因于共聚物链中电子密度的差异。CoP1.3 和 CoP1.5 的光学带隙值是根据中性态吸收计算的，分别为 1.21 eV 和 1.18 eV。由于共聚物骨架中的 EDOT 量较高，CoP1.5 的带隙低于 CoP1.3。CoP1.3 和 CoP1.5 在中性和氧化状态下都表现出不同颜色的多色行为。虽然两种共聚物（CoP1.3 和 CoP1.5）在中性状态下均呈现紫色，但在施加电位后颜色变为蓝色。光学对比度值计算为 31%（在 555 nm），CoP1.3 为 55%（1050 nm）和 38%（1240 nm），CoP1.5 为 34%（565 nm）、25%（975 nm）和 45%（1170 nm）。作为电致变色开关研究的结果，CoP1.3 的开关时间（氧化）计算为 2.5 秒、1.7 秒、1.9 秒和 CoP1.5 的 1.9 秒、1.8 秒、2.7 秒。此外，将 EDOT 单元添加到共聚物主链中导致电化学、光学、电致变色和动力学性能的明显改善。与均聚物相比，共聚物表现出全可见光吸收和红移中性吸收，具有较低的光学带隙值。CoP1.5 为 7 秒。此外，将 EDOT 单元添加到共聚物主链中导致电化学、光学、电致变色和动力学性能的明显改善。与均聚物相比，共聚物表现出全可见光吸收和红移中性吸收，具有较低的光学带隙值。CoP1.5 为 7 秒。此外，将 EDOT 单元添加到共聚物主链中导致电化学、光学、电致变色和动力学性能的明显改善。与均聚物相比，共聚物表现出全可见光吸收和红移中性吸收，具有较低的光学带隙值。