Photodimerization of 5,7-dimethoxycoumarin5,7-디메톡시쿠마린의 광이합체화 반응에 대한 연구

Direct irradiation of 5,7-dimethoxycoumarin (DMC) under N$_2$ produced three dimers such as anti head-to-head, syn head-to-head, and syn headto-tail. Relative yields of the three dimers changed with solvent polarity varying. In nonpolar solvents such as benzene, relative yield of anti head-to-head dimer is larger, while in polar solvents such as methyl alcohol syn head-to-tail and syn head-to-head dimer. Also, as solvent polarity increases from benzene to methyl alcohol, overall yields of dimers increase. In nonpolar solvents, rata of self-quenching is faster, while in polar solvents the rate of dimerization relative to self-quenching is faster. In the presence of triplet sensitizers such as benzophenone, the anti head-to-head dimer is formed exclusively in non-polar solvents but with traces of syn dimers in polar solvents. From sensitization and quenching experiments using azulene. We concluded that anti head-to-head dimer was formed via excited singlet state and syn dimers were formed via both excited singlet and triplet states. MAC 89463 9127
Advisors
Shim, Sang-Chul(심상철)researcher
Publisher
한국과학기술원
Issue Date
1991
Identifier
67641/325007 / 000891448
Language
eng
Description

학위논문(석사) - 한국과학기술원 : 화학과, 1991.2, [ vi, 47 p. ]

URI
http://hdl.handle.net/10203/32611
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=67641&flag=t
Appears in Collection
CH-Theses_Master(석사논문)
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