Efficient Photocycloreversion Reaction of Diarylethenes by Introduction of Cyano Subsutituents to the Reactive Carbons

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.