A Study of the Solvent Cage Effect involved in the Oxygen Quenching of Fluorescence and the Quenching of Singlet Oxygen.

1. 氧猝灭荧光：研究了正构烷烃（C2-C7）中氧对9,10 -二甲基镧（DMEA）的荧光猝灭作用。通过对淬火速率常数kg、溶剂笼内双分子速率kbimo和扩散速率kdiff的温度和压力依赖性分析，探讨了其淬火机理。氧在气相高温和高温高压下对荧光的猝灭：研究了氧在气相高温下对DMEA荧光的猝灭。利用新研制的高压池，研究了DMEA荧光在高温高压下的氧猝灭现象。从这些结果出发，讨论了溶剂笼效应。三重态的氧猝灭：(1)研究了9-乙酰镧（^3ππ^*）在超临界乙烷和二氧化碳中三重态的氧猝灭。从温度和压力对淬火速率常数k_q^T的依赖关系出发，讨论了扩散对淬火的影响和溶剂笼效应对淬火的影响。(2)研究了二苯甲酮（^3nπ^*）三重态在超临界二氧化碳中的氧猝灭随温度和压力的变化。从k_q^T的活化能、活化体积和单线态氧生成的量子产率出发，讨论了其猝灭机理。温度和压力对超临界流体中单重态氧（^1Δg）寿命的影响：测定了单重态氧在液体和超临界丙烷中温度和压力的函数，并从溶剂分子对双分子猝灭速率常数kD的活化参数和单重态氧与溶剂分子接触时径向分布函数g(σ) σ讨论了单重态氧的猝灭机理。少

1. Oxygen quenching of fluorescence :Fluorescence quenching of 9, 10-dimethylanthracene (DMEA) by oxygen in n-alkanes (C2-C7) was investigated. From the analysis of the pressure and temperature dependence of the quenching rate constant, kg, the bimolecular rate, kbimo, in the solvent cage and the diffusion rate constant, kdiff, were evaluated and the quenching mechanism was discussed.2. Oxygen quenching of fluorescence at high temperature in gas phase and at high temperature and high pressure :Fluorescence quenching of DMEA by oxygen in high temperature in gas phase was investigated. By using a high pressure cell, which was newly constructed for this work, oxygen quenching of fluorescence of DMEA at high temperature and high pressure was also investigated. From these results, the solvent cage effect was discussed.3. Oxygen quenching of the triplet states :(1) The oxygen quenching of the triplet states of 9-acetylanthracene (^3ππ^*) in supercritical ethane and carbon dioxide was investi … More gated. From the pressure and temperature dependence of the quenching rate constant, k_q^T, the quenching mechanism was discussed including the contribution of diffusion to the quenching and the solvent cage effect involved in the quenching. (2) The oxygen quenching of the triplet state of benzophenone (^3nπ^*) in supercritical carbon dioxide as functions temperature and pressure was investigated. From the activation energy and the activation volume for k_q^T, and the quantum yield of singlet oxygen formation, the quenching mechanism was discussed.4. Temperature and pressure effects on the lifetime of singlet oxygen (^1Δg) in supercritical fluids :Lifetime of singlet oxygen was measured as functions of temperature and pressure in liquid and supercritical propane, and the quenching mechanism was discussed from the activation parameters for the bimolecular quenching rate constant, kD, by the solvent molecule, and the radial distribution function, g(σ), at contact, σ, between the singlet oxygen and solvent molecules. Less