• 제목/요약/키워드: photoisimerization

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Photochemical Transformation of Chalcone Derivatives

  • Shin, Dong-Myung;Song, Dong-Mee;Jung, Kyoung-Hoon;Moon, Ji-Hye
    • Journal of Photoscience
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    • 제8권1호
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    • pp.9-12
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    • 2001
  • The photoisomerization behavior of benzylideneacetophenones, known as chalcones, was studied. We synthesized the chalcone derivatives that have ether groups at 4 and 4' positions. Due to the electron donating ability of the ether oxygen, the bond order of the single bond between two phenyl ring of the chalcone strengthened, which eventually increased the rotational barrier of the single bond. The rotational barrier of the single bond is about 20-22 kcal/mole. Thermal recovery of this process took about 1 min. The UV-visible spectra of these chromophores exhibit two characteristic absorption peaks at 276 nm and 340 nm. The relative intensity of the peaks varies depending on the alkyl chain length of the substituent. Photo-irradiation with the 365 nm light monotonously decreases the 340 nm peak. However, the photo-irradiation with 254 nm light induce two competing processes and produced rather complicated absorption profile.

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지방산과 인지질의 혼합비에 따른 단분자 LB막의 광이성질화 현상에 관한 연구 (Photoisomerization of Monolayer LB Films mixed with Fatty Acid and Phospholipid at mixture ratios)

  • 박근호;강동완;김성일;박태곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.479-482
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    • 2000
  • We investigated UV-vis absorbances to observe photoisimerization and effect of temperature using the mixture solution in chloroform and the LB monolayer mixed with DLPE and 8A5H containing azobenzene which shows reversible cis-trans isomerization irradiated by alternate lights. We could find that the absorption spectrum of the mixtures solution and LB monolayer was reversibly induced to photoisomerization irradiated by Uv of both and visible lights, in addition the absorbance by alternate temperatures.

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