2006 Fiscal Year Final Research Report Summary
A Study of the Solvent Cage Effect involved in the Oxygen Quenching of Fluorescence and the Quenching of Singlet Oxygen.
Project/Area Number |
17550010
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Physical chemistry
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Research Institution | Kyoto Institute of Technology |
Principal Investigator |
OKAMOTOI Masami Kyoto Institute of Technology, Graduate School of Science and Technology, Professor, 工芸科学研究科, 教授 (90115981)
|
Project Period (FY) |
2005 – 2006
|
Keywords | Solvent Cage Effect / Pressure Effect / Temperature Effect / Oxygen Quenching of Fluorescence / Oxygen Quenching of Triplet States / Triplet-Triplet Annihilation / Supercritical Fluids / Radial Distribution Function |
Research Abstract |
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
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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
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Research Products
(2 results)