This study reported on a variety of target phenanthridine dyes carrying hydroxy groups that were employed as near-IR two-photon absorption (TPA) photostabilizers for polymers. It was demonstrated that the target phenanthridine dyes underwent reversible excited state proton transfer (ESPT) in strong polar protic and aprotic solvents, such as ethanol, which was more remarkable under near-IR two-photon excitation. It was determined that the target dyes processed regular molecular stacking in mixed organic solvents/H₂O solvents (such as ethanol/H₂O, 90% water volume). The orderly molecular aggregation of the target phenanthridine dyes intensified the reversible ESPT emission under one-photon and near-IR two-photon excitation, respectively. Hence, the absorbed energy was consumed by the reversible ESPT process of the target dyes. As a consequence, the target dyes were evaluated as near-IR TPA photostabilizers for polymers. In contrast, the reference phenanthridine dyes lacking of hydroxy groups did not exhibit ESPT or photostability under light irradiation.

该研究报告了各种带有羟基的目标菲啶染料，这些染料被用作聚合物的近红外双光子吸收 (TPA) 光稳定剂。结果表明，目标菲啶染料在强极性质子和非质子溶剂（如乙醇）中经历了可逆激发态质子转移（ESPT），这在近红外双光子激发下更为显着。确定目标染料在混合有机溶剂/H ₂ O 溶剂（如乙醇/H ₂O，90% 的水体积）。目标菲啶染料的有序分子聚集分别增强了单光子和近红外双光子激发下的可逆 ESPT 发射。因此，目标染料的可逆 ESPT 过程消耗了吸收的能量。因此，目标染料被评估为聚合物的近红外 TPA 光稳定剂。相比之下，缺乏羟基的参考菲啶染料在光照射下没有表现出 ESPT 或光稳定性。