Exploring high-performance organic photocatalysts (PCs) for photoinduced electron/energy transfer reversible addition–fragmentation chain transfer (PET-RAFT) polymerization represents a cutting-edge research field. In this study, six donor (D)–acceptor (A) type organic PCs based on the pyrazino[2,3-f][1,10]phenanthroline structure were designed and synthesized, showcasing their successful application in PET-RAFT polymerization. Furthermore, diverse substituent groups were introduced to enable precise control over the photophysical and electrochemical properties of organic PCs. Time-dependent density functional theory (TD-DFT) analysis further identified two organic PCs (PCs 5 and 6) that exhibit thermally activated delayed fluorescence (TADF) characteristics. PCs 5 and 6 demonstrated high molar extinction coefficients (ε_max) and long delayed fluorescence (DF) lifetimes, achieving high-efficiency photopolymerization even at catalyst loadings as low as 0.1–10 ppm. This study elucidates the structure–activity correlation of such organic PCs while underscoring the facile construction of efficient PCs with TADF characteristics through strategic structural design. These findings serve as a valuable reference for advancing the development of high-performance organic PCs capable of light-induced reversible-deactivation radical polymerization (RDRP).

中文翻译：

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吡嗪并[2,3-f][1,10]菲咯啉衍生物作为强效光催化剂，实现 ppm 级有机催化光诱导电子/能量转移可逆加成-断裂链转移聚合

探索用于光诱导电子/能量转移可逆加成-断裂链转移（PET-RAFT）聚合的高性能有机光催化剂（PC）代表了一个前沿研究领域。在本研究中，设计并合成了六种基于吡嗪并[2,3- f ][1,10]菲咯啉结构的供体（D）-受体（A）型有机PC，展示了它们在PET-RAFT聚合中的成功应用。此外，引入不同的取代基可以精确控制有机PC的光物理和电化学性能。时间相关密度泛函理论 (TD-DFT) 分析进一步鉴定了两种具有热激活延迟荧光 (TADF) 特性的有机 PC（PC 5和6 ）。 PC 5和6表现出高摩尔消光系数 (ε _max ) 和长延迟荧光 (DF) 寿命，即使在催化剂负载量低至 0.1–10 ppm 的情况下也能实现高效光聚合。这项研究阐明了此类有机 PC 的结构-活性相关性，同时强调通过战略结构设计可以轻松构建具有 TADF 特征的高效 PC。这些发现为推进光诱导可逆失活自由基聚合（RDRP）高性能有机PC的开发提供了宝贵的参考。