Extraordinarily Low Cycloreversion Quantum Yields of Photochromic Diarylethenes with Methoxy Substituents
作者:Katsunori Shibata、Seiya Kobatake、Masahiro Irie
DOI:10.1246/cl.2001.618
日期:2001.7
Introduction of two methoxy substituents instead of methyl groups at the reactive carbons of 1,2-bis(5-phenyl-3-thienyl)perfluorocyclopentene decreased the photocycloreversion quantumyield by a factor of 103, while the cyclization quantumyield was similar.
Highly efficient photocycloreversion reaction was observed for diarylethene derivatives with cyano groups at the reactive carbons of the thiophene rings. The cycloreversion quantum yield of 1,2-bis(2-cyano-5-phenyl-3-thienyl)perfluorocyclopentene was found to be ca. 30 times larger than that of 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene.
A photochromic material having a ring opening quantum yield of 10
−3
or lower which does not fade under ambient light is provided. The material comprises a compound belonging to the diheteroarylethene class. The compound has alkoxy group and aryl group on the heteroaryl group.
An image forming medium includes a paper substrate and an imaging layer coated on or impregnated into a paper substrate, where the imaging layer is formed of an imaging composition that includes an alkoxy substituted diarylethene photochromic material dissolved or dispersed in a solvent or polymeric binder, and where the imaging composition exhibits a reversible transition between a colorless and a colored state.
An image forming medium includes a paper substrate and an imaging layer coated on or impregnated into a paper substrate, where the imaging layer is formed of an imaging composition that includes an alkoxy substituted diarylethene photochromic material dissolved or dispersed in a solvent or polymeric binder, and where the imaging composition exhibits a reversible transition between a colorless and a colored state.