Photochromism of diarylethenes having thiophene oligomers as the aryl groups
摘要:
Diarylperfluorocyclopentenes having thiophene oligomers as the aryl groups were synthesized and their photochromic reactivity was examined. The cylization quantum yields were scarcely affected by the oligomer chain length, while the ring-opening quantum yields dramatically decreased with the increasing number of the thiophene rings, The low quantum yield of a 1,2-bis(5 ''-cyano-2,4-dimethyl-5,2':5',2 ''-terthiophen-3-yl)perfluorocyclopentene closed-ring form was increased as large as 34 times by raising the reaction temperature from 25 degrees C to 150 degrees C. (C) 1997 Elsevier Science Ltd.
Photochromism of Dithienylethenes with Electron-Donating Substituents
摘要:
Bis(2,4-dimethyl-5-phenylthiophene-3-yl) having hydrogen, methoxy, diethylamino, or cyano substituents at para-positions of the phenyl groups were synthesized to reveal the effect of the substitution on the absorption coefficient epsilon of the closed-ring forms and the photochemical reactivity. Electron-donating substituents, such as methoxy or diethylamino groups, were found to be effective to increase the absorption coefficient and to decrease the ring-opening quantum yield. The cyclization quantum yield was scarcely affected by the substitution. The conversion from the open- to the closed-ring forms of the diethylamino-substituted compound in the photostationary state under irradiation with 313 nm light was close to 100%.
A Photochromic Dithienylethene That Turns Yellow by UV Irradiation
作者:Kingo Uchida、Masahiro Irie
DOI:10.1246/cl.1995.969
日期:1995.11
1,2-Bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene which shows a reversible color change from colorless to yellow by UV irradiation was synthesized. The color of the photogenerated closed-ring forms was dependent on the substitution position of the thiophene rings to the perfluorocyclopentene moiety.
Two types of diarylethene, each of which contains a naphthalene and a thiophenering, were synthesized, and their photochromicproperties were studied. The photochromicproperties are dependent on the bridge position of the thiophenering. The cycloreversion of one of the closed forms of some of the diarylethenes occurred almost photon quantitatively, and the photochromic reactions were thermally irreversible
Multi-dithienylethene arrays, in which two, three, or four 1,2-bis(2,4-dimethylthiophen-3-yl)perfluorocyclopentenes are ethynylene-bridged, were synthesized. Upon irradiation with ultraviolet light the hexane solutions of the arrays turned violet-blue and the color disappeared by irradiation with visible light. The quantum yields of photocyclization reactions successively increased from 0.21 to 0.40 by increasing
A photochromic latex ink includes an organic polymer; optionally a colorant, and a photochromic compound. The photochromic ink composition has an average particle size from about 20 nm to about 600 nm. The photochromic ink composition is capable of reversibly converting from a first color to a second color in response to a predetermined wavelength scope.
Excited State Energy Migration and Photochromic Reaction in 1,2-Bis(2,4-dimethyl-3-thienyl)perfluorocyclopentene Single Crystal
作者:Seiya Kobatake、Hiroaki Muto、Masahiro Irie
DOI:10.1246/cl.2006.102
日期:2006.1
An excited state energy migration was found to compete with a photocyclization reaction in the single crystal of 1,2-bis(2,4-dimethyl-3-thienyl)perfluorocyclopentene.