Thermally Irreversible Photochromic Systems. Photoreaction of Diarylethene Derivatives with Imidazo[1,2-<i>a</i>]pyridine Rings
作者:Yasuhide Nakayama、Koichiro Hayashi、Masahiro Irie
DOI:10.1246/bcsj.64.202
日期:1991.1
A non-symmetrical diarylethene with imidazo[1,2-a]pyridine ring on one end and thiophene ring on the other end, 1,2-dicyano-1-(2-methylimidazo[1,2-a]pyridin-3-y1)-2-(2,4,5-trimetyl-3-thieny1)ethene 2Z underwent a hexatriene-cyclohexadiene type reversible ring-closure reaction by photoirradiation, while an only Z–E isomerization was observed for a symmetrical diarylenthene with two imidazo[1,2-a]pyridine
一种非对称二芳基乙烯,一端带有咪唑并[1,2-a]吡啶环,另一端带有噻吩环,1,2-二氰基-1-(2-甲基咪唑并[1,2-a]吡啶-3- y1)-2-(2,4,5-trimetyl-3-thieny1)ethene 2Z 通过光照射发生了己三烯-环己二烯型可逆闭环反应,而对于具有两个咪唑的对称二亚芳基仅观察到 Z-E 异构化[1,2-a]吡啶环,1,2-二氰基-1,2-双(2-甲基咪唑并[1,2-a]吡啶-3-基)乙烯1Z。未观察到闭环反应。光生闭环形式 2C 在 535 nm 处具有吸收带,比相应的二噻吩乙烯长 23 nm 波长,并且在 80°C 下保持吸收强度恒定超过 24 小时。