Kuimova Marina K, Hoffmann Markus, Winters Mikael U, Eng Mattias, Balaz Milan, Clark Ian P, Collins Hazel A, Tavender Susan M, Wilson Craig J, Albinsson Bo, Anderson Harry L, Parker Anthony W, Phillips David
Chemistry Department, Imperial College London, Exhibition Road, SW7 2AZ, UK.
Photochem Photobiol Sci. 2007 Jun;6(6):675-82. doi: 10.1039/b700557a. Epub 2007 Apr 3.
We report a systematic study of the photophysical parameters relevant to photodynamic therapy (PDT) by a new type of sensitizers, conjugated porphyrin oligomers. Due to the strong nonlinear properties of oligomers containing 2, 4 and 8 porphyrin units, these molecules are attractive candidates for PDT via multiphoton excitation. The triplet state energy levels for all molecules have been determined by the triplet quenching method, phosphorescence measurements and DFT calculations. We find that the triplet energies of all the oligomers are sufficient to generate singlet oxygen, >94 kJ mol(-1). However, low singlet oxygen quantum yields are observed for the tetramer and the octamer, as compared to the conjugated dimer and monomeric porphyrin, reflecting the decrease in triplet yield. Thus the conjugated porphyrin dimer is the most promising core structure for PDT applications via multiphoton excitation.
我们报告了一项关于新型敏化剂——共轭卟啉低聚物与光动力疗法（PDT）相关光物理参数的系统研究。由于含有2、4和8个卟啉单元的低聚物具有很强的非线性特性，这些分子是通过多光子激发进行光动力疗法的有吸引力的候选物。所有分子的三重态能级已通过三重态猝灭法、磷光测量和密度泛函理论（DFT）计算确定。我们发现，所有低聚物的三重态能量足以产生单线态氧，>94 kJ mol⁻¹。然而，与共轭二聚体和单体卟啉相比，四聚体和八聚体的单线态氧量子产率较低，这反映了三重态产率的降低。因此，共轭卟啉二聚体是通过多光子激发用于光动力疗法应用的最有前景的核心结构。
