金属酞菁激发态与氧的相互作用

比较了几种金属酞菁光敏产生单重态氧和超氧负离子的能力,结果表明它们产生~1O_2的能力与中心金属的电子结构有关,取决于三重态寿命和量子产率。顺序如下:Zn>Ga>Cu>H_2>Al>Co。产生O_2~-的能力不仅与三重态寿命和量子产率有关,也与激发能和氧化还原电位有关。其顺序如下:Ga>Al>Cu>Zn。还研究了酪氨酸与镓酞菁激发态相互作用,酪氨酸猝灭镓酞菁荧光。在除氧条件光激发下,酪氨酸猝灭镓酞菁的激发三重态发生电子转移,检测到GaTSPc~-在560nm处的瞬态吸收,在氧的存在下进一步反应生成O_i~-。

INTERACTION OF METAL PHTHALOCYANINE EXCITED STATES WITH MOLECULAR OXYGEN

In this paper, the ability of photo generation of singlet oxygen as well as superoxide radical sensitized by metal phchalocyanines was evaluated. The results show that the ability of photo-generation of singlet oxygen is correlated with the triplet yield and tripet life time of the sen-sitizer The activity decreases in the order Zn>Ga>Cu>H2>Al>Co. The ability of photogene-ration of superoxide radical depends not only on the triplet yield and triplet life time but also the excited energy and redox potential of the sensitizer. The ability decreases in the order Ga> Al>Cu>Zn. The fluorescence of metal phthalocyanine is quenched by tyrosine via electron transfer. Quenching of Ga phthalocyanine triplet state in deaerated solution by tyrosine giving rise to GaPc- at 560nm. In oxygenated solution, subsequent electron transfer to oxygen occurs to give superoxide radical.