Xia W L, Zhang M H, Jiang L J, Wang Z J
Institute of Photographic Chemistry, Academia Sinica, Beijing, PRC.
Sci China B. 1992 Dec;35(12):1409-15.
In this paper, the nanosecond transient absorption spectra and the fluorescence spectra of Hypocrellin A(HA) are examined in solvents of varying polarity. There are three absorption bands in dilute HA solutions: Ia, IIa are defined as the triplet-triplet absorption of HA, the band IIIa is supposed to be the absorption of the solvent-separated ion pair (SSIP). In more concentrated solutions, only the absorption of SSIP was observed. The effects of solvent polarity on transient absorption spectra and fluorescence spectra of HA and the effect of oxygen on the intensities of the fluorescence of HA are discussed. Then a reasonable mechanism for the photolysis of HA is proposed.
本文研究了竹红菌素A（HA）在不同极性溶剂中的纳秒瞬态吸收光谱和荧光光谱。在稀HA溶液中有三个吸收带：Ia、IIa被定义为HA的三重态-三重态吸收，带IIIa被认为是溶剂分离离子对（SSIP）的吸收。在浓度更高的溶液中，仅观察到SSIP的吸收。讨论了溶剂极性对HA瞬态吸收光谱和荧光光谱的影响以及氧对HA荧光强度的影响。然后提出了一个合理的HA光解机理。
