单重态氧化学 Ⅵ.胶束中竹红菌甲素诱导的二苯基异苯并呋喃光敏氧化反应动力学

Singlet Oxygen Chemistry Ⅵ. The Kinetics of Photooxygenation of 2, 5-Diphenylbenzofran (DPBF) Induced by Hypocreallin A (HA) in Micelles

本文研究了增溶于胶束内部的HA诱导的DPBF光敏氧化动力学。测定了DPBF在不同胶束中光敏氧化总速率常数,分别为5.12×10~9(SDS),2.31×10~9(Triton X-100)和6.21×10~9L/mol·s(TDPB)。实验证明胶束可有效猝灭单重态氧却不猝灭HA的激发三重态,从而导致DPBF光敏氧化双分子反应可按假一级动力学规律处理,可求出表观速率常数为1.52×10^(-3)s^(-1)(SDS)或1.54×10^(-3)s^(-1)(Triton X-100),相应的半寿命为7.5min。这些结果为HA在水溶液中的光动态行为的研究提供了依据。

Tne kinetics of photooxygenation of DPBF induced by HA in micellar aqueous were investigated. The total rate constants of photooxygenation of DPBF are 5.12×10~9L/mol·s in SDS, 2.31×10~9L/mol·s in TX-100 and 6.21×109L/mol·s in TDPB respectively.The experiments showed that mice]des can efficiently quench singlet oxygen other than the excited triplet state of HA, it make possible to treat the kinetics of bimolecular photosensitized oxidation of DPBF to be a quasi-first order rule, so that the apparent rate constant was calculeted from the slope of linear equation which is 1.52×10^(-3)s^(-1) in SDS or 1.54×10^(-3)s^(-1) in TX-100 respectively and the half life time is 7.5 rain.