This study focuses on examining the design principles of creating multi-heterocycle chromophores with a discrete conjugation length, which absorb ultraviolet light in the neutral state and upon oxidation absorb throughout a broad spectral range in the visible region. In this analysis, three discrete-length chromophore polymers with alkylene linkers were examined via time dependent DFT, which were synthesized via direct heteroarylation polymerization, and the electrochromic properties of their thin films were characterized. Using a feedback loop of theoretical calculations with design and synthesis, we elucidate how steric interactions can be used to control the absorption of the neutral and oxidized states of these discrete chromophore polymers. We show that systems with high inter-ring strain can be used to increase the molar absorptivity of the charged state by forming multiple radical cation states on a single discrete chromophore. We also demonstrate the challenges of electrochemical redox reversibility in the solid state in these systems, while they maintain their chemical redox reversibility.

中文翻译：

---

亚烷基连接的离散发色团聚合物的电致变色，具有宽的自由基阳离子吸光度†

这项研究的重点是研究创建具有不同共轭长度的多杂环发色团的设计原理，该发色团吸收中性态的紫外光，并在氧化作用下吸收可见光区域的宽光谱范围。在此分析中，通过时间依赖性DFT检测了三种具有亚烷基接头的离散长度发色团聚合物，它们是通过以下方法合成的直接杂芳基聚合，并表征了其薄膜的电致变色性能。使用理论计算与设计和合成的反馈回路，我们阐明了空间相互作用可如何用于控制这些离散发色团聚合物的中性和氧化态的吸收。我们表明具有高环间应变的系统可用于通过在单个离散生色团上形成多个自由基阳离子态来增加带电态的摩尔吸收率。我们还展示了在这些系统中固态保持电化学氧化还原可逆性的同时，电化学氧化还原可逆性所面临的挑战。