We report herein the synthesis of aza‐BODIPY substituted with strongly electron‐donating p‐(diphenylamino)phenyl substituents (p‐Ph₂N−) at 3,5‐positions. The presence of p‐Ph₂N− groups lowers the energy of the singlet excited state (E_s) to 1.48 eV and induces NIR absorption with λ_abs at 789 nm in THF. The compound studied is weakly emissive with the emission band (λ_f) at 837 nm and with the singlet lifetime (τ_S) equal to 100 ps. Nanosecond laser photolysis experiments of the aza‐BODIPY in question revealed T₁→T_n absorption spanning from ca. 350–550 nm with the triplet lifetime (τ_T) equal to 21 μs. By introducing a heavy atom (Br) into the structure of the aza‐BODIPY, we managed to turn it into a NIR operating photosensitizer. The photosensitized oxygenation of the model compound–diphenylisobenzofuran (DPBF)‐proceedes via Type I and/or Type III mechanism without formation of singlet oxygen (¹O₂). As estimated by CV/DPV measurements, the p‐Ph₂N− substituted aza‐BODIPYs studied exhibits oxidation processes at relatively low oxidation potentials (E_ox¹), pointing to the very good electron‐donating properties of these molecules. Extremely high photostability and thermal robustness up to approximately 300 °C are observed for the p‐Ph₂N− substituted aza‐BODIPYs.

中文翻译：

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近红外光敏Aza-BODIPY：耐热，光稳定的光敏剂和高效的电子给体。

我们在此报告在3,5-位被强供电子的p-（二苯基氨基）苯基取代基（p- Ph ₂ N-）取代的aza-BODIPY的合成。存在p -Ph _2次N-基团降低了单重激发态（能量ë_小号）到1.48 eV和诱导NIR吸收与λ_腹肌在THF 789纳米。所研究的化合物是与发射带（弱发射λ _˚F在837纳米），并与单寿命（τ_小号）等于100皮秒。所研究的aza-BODIPY的纳秒激光光解实验显示T ₁ →T _n吸收范围从大约 与三线态寿命（350-550纳米τ _Ť）等于21微秒。通过将重原子（Br）引入到aza-BODIPY的结构中，我们设法将其转变为NIR操作型光敏剂。通过I型和/或III型机理对模型化合物二苯基异苯并呋喃（DPBF）进行光敏氧化而不会形成单线态氧（¹ O ₂）。根据CV / DPV测量估计，所研究的p- Ph ₂ N-取代的aza-BODIPYs在相对较低的氧化电势下表现出氧化过程（E _ox ¹），指出这些分子具有非常好的供电子特性。对于p- Ph ₂ N-取代的aza-BODIPY，观察到极高的光稳定性和高达300°C的热稳定性。