The nature of intramolecular charge transfer of N,N-diaryl dihydrophenazine photocatalysts (PCs) in different solvents is explored in context of their performance in organocatalyzed atom transfer radical polymerization (O-ATRP). PCs having a computationally predicted lowest energy excited state exhibiting charge transfer (CT) character can operate a highly controlled O-ATRP in a wide range of solvent polarities, from non-polar hexanes to highly polar N,N-dimethylacetamide. For PCs having a computationally predicted lowest energy excited state not possessing CT character, their ability to operate a controlled O-ATRP is decreased. This study confirms the importance of CT character in the excited state for N,N-diaryl dihydrophenazine PCs, and a deeper understanding of the activity of CT PCs has enabled the synthesis of polymers of low dispersity ( < 1.10) in a controlled fashion.

中文翻译：

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溶剂对有机催化原子转移自由基聚合 N,N-二芳基二氢吩嗪催化剂分子内电荷转移特性的影响。

结合 N,N-二芳基二氢吩嗪光催化剂 (PC) 在有机催化原子转移自由基聚合 (O-ATRP) 中的性能，探讨了 N,N-二芳基二氢吩嗪光催化剂 (PC) 在不同溶剂中的分子内电荷转移性质。具有计算预测的最低能量激发态并表现出电荷转移（CT）特性的 PC 可以在各种溶剂极性（从非极性己烷到高极性 N,N-二甲基乙酰胺）中操作高度受控的 O-ATRP。对于具有计算预测的最低能量激发态但不具备 CT 特征的 PC，它们操作受控 O-ATRP 的能力会降低。这项研究证实了 N,N-二芳基二氢吩嗪 PC 在激发态下的 CT 特性的重要性，并且对 CT PC 活性的更深入了解使得能够以受控方式合成低分散度（< 1.10）的聚合物。