• 제목/요약/키워드: photochromism

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Synthesis of Liquid Crystalline Spiroxazine Derivatives

  • Cui, Jian-Zhong;Kim, Jae-Ho;Kim, Sung-Hoon
    • Fibers and Polymers
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    • 제2권3호
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    • pp.117-121
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    • 2001

  • Liquid crystalline spiroxazine derivatives have been synthesized. The spiroxazines obtained were characterized by H-NMR, IR spectroscopy, UV and GC-MS.

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Size and Crystal Structure Dependence of Photochromism of Nanocrystalline WO3 and MoO3 Prepared by Acid-Precipitation Method

  • Jun Young, Kwak;Young Hee, Jung;Yeong Il, Kim
    • 대한화학회지
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    • 제67권1호
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    • pp.33-41
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    • 2023

  • Nanocrystallne WO3 and MoO3 with several different sizes and crystal structures were prepared by simple acid precipitation and subsequent heat treatment. The photochromic (PC) properties of these samples were comparatively investigated in powder state by monitoring diffuse reflectance spectral changes after bandgap irradiation. The PC effect of hexagonal WO3 and monoclinic WO3 strongly depended upon crystallite size rather than crystal structure. The smaller the crystallite size, the better the PC effect. However, orthorhombic WO·H2O and MoO3 having hexagonal and orthorhombic structures did not follow this trend. One consistent result for all WO3 and MoO3 samples is that the heat treatment in air, which changes crystallinity, whether it changes the crystal structure or only the crystallite size, reduces the PC effect. Since the thermal treatment reduces the surface oxygen defect sites, we believe that the PC effect of WO3 and MoO3 depends critically on the surface oxygen defect sites that serve as deep trap sites for photogenerated electrons and oxygen radical holes. We also found that the proton insertion claimed by double charge injection model is not critical for the PC effect.

  • https://doi.org/10.5012/jkcs.2023.67.1.33 인용 PDF HTML

Synthesis of New Bicyclic Aziridines Containing Chalcone Analogs and Investigation of Their Photochromic Properties

  • Besharati-Seidani, Tayebeh;Mahmoodi, Nosrat O.
    • Bulletin of the Korean Chemical Society
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    • 제34권3호
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    • pp.875-883
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    • 2013

  • Ten new derivatives of 1,3-diazabicyclo[3.1.0]hex-3-enes linked via ether linkage to chalcones were synthesized and characterized by UV, FT-IR, $^1H$ NMR and $^{13}C$ NMR spectral techniques. The spectra of all synthesized compounds, confirmed structure-photochromic behavior relationships (SPBR) both in solution or in solid state by irradiation under UV light at 254 nm. In other efforts for first time photochromic behavior of ketoaziridines has been investigated.

  • https://doi.org/10.5012/bkcs.2013.34.3.875 인용 PDF KSCI

광 도파관을 이용한 전이금속 화합물의 광색성연구 (Study on Photochromism for Transition Metal Compounds by Using the Optieal Waveguide)

  • 이시우
    • 한국인쇄학회지
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    • 제10권1호
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    • pp.1-13
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    • 1992

  • The recent results concerning the synthesis and application of spiroxazine dyes have been summerized., The absorption bands of usual spiroxazine dyes are changed from colorless to colored from by irradiation of ultraviolet ray. This mechanism is derived from the cleavage of oxazine ring. Such properties are dependent on its chemical structure and surrounded matrix of spiroxazine dyes. the chemical structure of this dye is similar to the well known spriopyran. But spiroxazine dyes have noticed recently, because of excellent high light-sensitivity and superior fatigue-resistant property. This dye are already applied as photochromic lens, cloths and UV light checker.

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