Recently, electro-switchable optical materials have attracted much attention for their promising applications in optoelectronic devices and biological analysis. The structures of active optical moieties are dominant for the resulting performance, which raises the requirement of studying their structure-property relationship. In this study, two p-phenylenediamine–based polyamides (α-HPA and β-HPA) containing α-/β-substituted pendant naphthalene were designed and synthesized to investigate the effect of two substitution sites of naphthalene on their thermal, optical, electrochemical, electrochromic, and electrofluorochromic behaviors. Quantum chemical calculations were carried out to help the analysis of the experimental results. The as-prepared polyamides both exhibited excellent solubility, thermal stabilities (no weight loss before 300 °C in air), and optical switching stability (500 cycles). Because of the more twisted conformation and stronger charge transfer effect between diphenylamine and α-substituted naphthalene, the α-HPA exhibited higher glass transition temperature, higher coloration efficiency, weaker fluorescence quantum efficiency, red-shifted emission wavelength, and rapider switching speed than the β-HPA. This study not only presents a deep understanding of substitution sites of fluorophores on the electro-switchable optical behaviors but also demonstrates the tailorability of the electrochromic/electrofluorochromic characteristics through fine structure adjustment, paving a pathway for further development of high-performance electrochromic/electrofluorochromic materials.

近年来，电开关光学材料因其在光电器件和生物分析中的应用前景而备受关注。活性光学部分的结构对所产生的性能起主导作用，这提出了研究它们的结构-性质关系的要求。在这项研究中，两个p设计并合成了含有 α-/β-取代侧萘的苯二胺基聚酰胺（α-HPA 和 β-HPA），以研究萘的两个取代位点对其热、光学、电化学、电致变色和电致荧光变色行为的影响. 进行了量子化学计算以帮助分析实验结果。所制备的聚酰胺均表现出优异的溶解性、热稳定性（在空气中 300°C 前无重量损失）和光开关稳定性（500 次循环）。由于二苯胺和α-取代萘之间的扭曲构象和更强的电荷转移效应，α-HPA表现出更高的玻璃化转变温度、更高的着色效率、更弱的荧光量子效率、红移发射波长、和比 β-HPA 更快的开关速度。本研究不仅深入了解荧光团的取代位点对电致变色光学行为的影响，而且通过精细结构调整证明了电致变色/电致变色特性的可定制性，为进一步开发高性能电致变色/电致变色材料铺平了道路.