Photophysical Efficiency Factors of Singlet Oxygen Generation from Core-modified Trithiasapphyrin Derivatives
Photophysical Efficiency Factors of Singlet Oxygen Generation from Core-modified Trithiasapphyrin Derivatives
复制标题
核心改性三硫代蓝宝石衍生物产生单线态氧的光物理效率因素
DOI：
10.5012/bkcs.2002.23.2.281
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发表时间：
2002
影响因子：
1.7
通讯作者：
Yong Rok Kim
中科院分区：
文献类型：
--
作者：
Jeong;Min Sun Kim;Yong;ShinHyung Ryu;Mignon Park;K. Shin;Yong Rok Kim
研究了内消旋四苯基三硫代蓝宝石（S 3 TPS）和内消旋四（对甲氧基苯基）三硫代蓝宝石（（p-MeO）-S 3 TPS）的光物理性质和单线态氧生成效率，利用稳态和时间分辨光谱方法阐明了它们作为光动力疗法（PDT）光敏剂的可能性。观察到的光物理性质与其他类卟啉光敏剂在几何和电子结构方面的光物理性质进行了比较，例如扩展π共轭、结构畸变和内部重原子。由于扩展的π共轭，稳态电子吸收和荧光光谱均发生红移。测量到的荧光量子产率非常小。尽管由于自旋轨道耦合的增加，系间穿越率预计会增加，但三重态量子产率测得小于 0.15。这些特征可以归因于与系统间交叉率相比更高的内部转换率。此外，三重态寿命如预期缩短至~1.0 μs。因此，由于快速的三重态衰减速率和向氧分子的低效能量转移以及低三重态量子产率，单线态氧量子产率估计接近于零。能量转移到氧分子的低效率可归因于较低的氧化电势和/或能量较低的三重态。应仔细评估此类光物理因素作为潜在的光敏剂，这些光敏剂具有扩展的 π 共轭和合成的重核原子以实现红移吸收和高三重态量子产率。
The photophysical properties and the singlet oxygen generation efficiencies of meso-tetraphenyl-trithiasapphyrin (S 3 TPS) and meso-tetrakis(p-methoxyphenyl)-trithiasapphyrin ((p-MeO)-S 3 TPS) have been investigated, utilizing steady-state and time-resolved spectroscopic methods to elucidate the possibility of their use as photosensitizers for photodynamic therapy (PDT). The observed photophysical properties were compared with those of other porphyrin-like photosensitizers in geometrical and electronic structural aspects, such as extended π conjugation, structural distortion, and internal heavy atoms. The steady-state electronic absorption and fluorescence spectra were both red-shifted due to the extended π-conjugation. The fluorescence quantum yields were measured as very small. Even though intersystem crossing rates were expected to increase due to the increment of spin orbital coupling, the triplet quantum yields were measured as less than 0.15. Such characteristics can be ascribed to the more enhanced internal conversion rates compared with the intersystem crossing rates. Futhermore, the triplet state lifetimes were shortened to ∼1.0 μs as expected. Therefore, the singlet oxygen quantum yields were estimated to be near zero due to the fast triplet state decay rates and the inefficient energy transfer to the oxygen molecule as well as the low triplet quantum yields. The low efficiencies of energy transfer to the oxygen molecule can be attributed to the lower oxidation potential and/or the energetically low lying triplet state. Such photophysical factors should be carefully evaluated as potential photosensitizers that have extended π-conjugation and heavy core atoms synthesized for red-shifted absorption and high triplet state quantum yields.
使用连续调制激光二极管的相位荧光测定法。
影响因子：
7.4
作者：
Thompson,RichardB;Frisoli,JoanK;Lakowicz,JosephR
通讯作者：
Lakowicz,JosephR
影响因子：
3.3
作者：
L. Roitman;B. Ehrenberg;Y. Nitzan;V. Král;J. Sessler
通讯作者：
L. Roitman;B. Ehrenberg;Y. Nitzan;V. Král;J. Sessler