Zhao Fang, Zhan Xuan, Lai Shu-Hui, Zhang Lei, Liu Hai-Yang
State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University Guangzhou 510275 China
Department of Chemistry, The Key Laboratory of Fuel Cell Technology of Guangdong Province, South China University of Technology Guangzhou 510641 China
RSC Adv. 2019 Apr 24;9(22):12626-12634. doi: 10.1039/c9ra00928k. eCollection 2019 Apr 17.
In order to study the effect of -iodination of free-base corroles on their photophysical character, we designed and synthesized a series of free-base corrole derivatives F10-OH (iodine-free), F10-OH-I (mono-iodo) and F10-OH-2I (di-iodo), with different substitution patterns at the -position as candidates for photodynamic therapy (PDT). We employed several optical spectroscopic techniques, including time-resolved spectroscopy from a femtosecond to microsecond and singlet oxygen luminescence to study the properties of excited singlet and triplet states, as well as the singlet oxygen quantum yields. The sub-picosecond internal conversion, ∼1 ps intramolecular vibrational energy redistribution, tens of ps vibrational cooling, are similar across the three corroles. The addition of one (F10-OH-I) and two iodine (F10-OH-2I) atoms to the remote aryl ring of triarylcorroles induces a 4.6-fold and 6.2-fold decrease in fluorescence quantum yields and a 2.2-fold and 4.9-fold increase in the time constant of intersystem crossing . In addition, a slight increase in intersystem crossing quantum yields was also observed from F10-OH to F10-OH-2I. It means the intersystem crossing is improved by the iodination, from F10-OH to F10-OH-2I, because of the heavy atom effect. However, the sample F10-OH-I, instead of F10-OH-2I, shows the highest singlet oxygen quantum yield .
为了研究游离碱卟啉的碘化对其光物理性质的影响，我们设计并合成了一系列游离碱卟啉衍生物F10-OH（无碘）、F10-OH-I（单碘）和F10-OH-2I（双碘），它们在β位具有不同的取代模式，作为光动力疗法（PDT）的候选物。我们采用了几种光谱技术，包括从飞秒到微秒的时间分辨光谱和单线态氧发光，来研究激发单重态和三重态的性质以及单线态氧量子产率。三种卟啉的亚皮秒内转换、约1皮秒的分子内振动能量重新分布、几十皮秒的振动冷却情况相似。在三芳基卟啉的远程芳环上添加一个（F10-OH-I）和两个碘原子（F10-OH-2I）会导致荧光量子产率分别降低4.倍和6.2倍，系间窜越时间常数分别增加2.2倍和4.9倍。此外，从F10-OH到F10-OH-2I还观察到系间窜越量子产率略有增加。这意味着由于重原子效应，从F10-OH到F10-OH-2I，碘化改善了系间窜越。然而，样品F10-OH-I而非F10-OH-2I显示出最高的单线态氧量子产率。
