title: Polymorphism of 1,2-Bis(2-methyl-5-p-methoxyphenyl-3-thienyl)perfluorocyclopentene and Photochromic Reactivity of the Single Crystals.
abstract: Four polymorphic crystals were obtained by recrystallization of 1,2-bis(2-methyl-5-p-methoxyphenyl-3-thienyl)perfluorocyclopentene (1 a) from hexane. All crystals underwent photochromic reactions upon alternate irradiation with ultraviolet (lambda=370 nm) and visible light (lambda>500 nm). The photocyclization quantum yields were found to be close to unity irrespective of the crystal types, while the photocycloreversion quantum yields were different as much as four times depending on the conformation of the closed-ring isomers in the crystals.
authors.affiliation: Department of Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Morimoto
authors.forename: Seiya
authors.initials: S
authors.lastname: Kobatake
authors.forename: Masahiro
authors.initials: M
authors.lastname: Irie