DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Shim, Sang-Chul | - |
dc.contributor.advisor | 심상철 | - |
dc.contributor.author | Han, Gyu-Seok | - |
dc.contributor.author | 한규석 | - |
dc.date.accessioned | 2011-12-13T05:01:04Z | - |
dc.date.available | 2011-12-13T05:01:04Z | - |
dc.date.issued | 1996 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=105605&flag=dissertation | - |
dc.identifier.uri | http://hdl.handle.net/10203/32746 | - |
dc.description | 학위논문(석사) - 한국과학기술원 : 화학과, 1996.2, [ v, 52 p. ] | - |
dc.description.abstract | An efficient synthesis of 6,8-dioxa-1,4-diazacyclopenta[b]phenanthren-5 -one (Pyrazino-psoralen) (1) has been carried out by the Suzuki coupling reaction as a key step starting from 5-bromo-6-methoxybenzofuran (6a) and methyl 2-iodo-3-pyrazinecarboxylate (8). Pyrazinopsoralen (PzPs) had a similar UV-Visible absorption spectrum with other psoralens and showed stronger long-UVA absorption than 8-MOP. The $λ_{max}$ of UV absorption of PzPs shifted to longer wavelength with increasing solvent polarity, indicating that these UV absorption was due to the π→$π^*$ transition. It shows a much lower fluorescence quantum yield (0.0008 in ethanol at room temperature) than other psoralens as expected due to the increased proximity effect of $^1(n, π^*)$ to $^1(π, π^*)$ state. The fluorescence lifetime was 1.05 ns in nonpolar methylcyclohexane with a single exponential decay behavior, while more than two components were observed in other solvents with major pre-exponential factor in the short-lived component (〉95%). The triplet state of PzPs was not observable by phosphorescence, laser flash excitation, and singlet oxygen formation. It is very likely that the proximity of the $^1(n, π^*)$ state to the $^1(π, π^*)$ state leads to rapid radiationless decay such as $S_1~〉S_0, S_1~〉T_1$ and $T_1~〉S_0$. | eng |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | Proximity effect | - |
dc.subject | Pyrazinopsoralen | - |
dc.subject | PUVA therapy | - |
dc.subject | PUVA치료 | - |
dc.subject | 근접효과 | - |
dc.subject | 피라지노소랄렌 | - |
dc.title | Synthesis and photophysical properties of pyrazinopsoralen | - |
dc.title.alternative | 피라지노소랄렌의 합성과 광물리적 성질에 관한 연구 | - |
dc.type | Thesis(Master) | - |
dc.identifier.CNRN | 105605/325007 | - |
dc.description.department | 한국과학기술원 : 화학과, | - |
dc.identifier.uid | 000943567 | - |
dc.contributor.localauthor | Shim, Sang-Chul | - |
dc.contributor.localauthor | 심상철 | - |
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