Development of time-resolved diffuse reflectance laser photolysis method and its application to solid photochemistry
| Project/Area Number |
61470006
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理化学一般
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
MASUHARA Hiroshi Kyoto Institute of Technology Professor, 繊維学部, 教授 (60029551)
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| Co-Investigator(Kenkyū-buntansha) |
IKEDA Noriaki Kyoto Institute of Technology Assistant Prof, 繊維学部, 助手 (70176098)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1986: ¥5,700,000 (Direct Cost: ¥5,700,000)
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| Keywords | Time-resolution / Deffuse reflection / Laser photolysis / Nanosecond Picosecond / Pwder / 吸着 / 時間分解分光法 / 拡散反射スペクトル / 過渡吸収スペクトル / 光化学初期過程 / 中間体 / ナノピコ秒 |
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| Research Abstract |
We have developed microcomputer-controlled nanosecond and picosecond diffuse reflectance laser photolysis systems, which make it possible to measure UV absoprption spectra of excited states as well as transient chemical species in opaque and scattering materials and to analyze their dynamic behavior. The nanosecond system is the unique one in this country, while the picosecond study was performed for the first time in the present project. Using these systems, we demonstrated that photophysical and phtochemical processes of various kinds of scattering material and revealed the factors affecting absorption spectral shape and rese as well as decay curves of transient species.
On the basis of these experimental results. we proposed an empirical equation, Ao = aA exp(bA), in order to get accurate and reliable data.Here Ao is a corrected absorption and A is % absorption used as a measure in diffuse reflectance laser photolysis measurement. This correction method seemed to be fruitful, for example, the corrected T-T absorption spectrum of benzophenone microcrystals was quite similar to the corresponding one of its single crystal. In order to interpret the physical meaning of this equation, we performed a simulation of diffuse reflectance phenomena due to Kebelka's theory and Wilkinson's method. Scattering coefficient, molar extinction coefficients of the ground and transient states, and excitation internsity were examined as paprmeters. We have come to the conclusion that there is a definite relation between % absorption and transient absorption where molar extinction coefficient of the ground state and excitation intensity can be abjusted. This means that diffuse reflectance laser photolysis is promising for solid organic photochemistry as transmittance laser photolysis is fruitful for solution systems.
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Report
(2 results)
Research Products
(11 results)
