title: Photochromism of a diarylethene having an azulene ring.
abstract: Diarylethene derivatives incorporating an azulene ring at the ethene moiety were synthesized. One derivative having thiazole rings showed the expected coloration reaction by excitation at 313 nm (to a higher singlet state) but not when excited at 635 nm (S(0) to S(1) excitation). The system demonstrates that the cyclization reaction can be controlled by selective excitation at different wavelengths of the absorption spectrum. On the other hand, another derivative having thiophene rings did not show any photochromism. The results clearly show the importance of the coplanarity of the system for the photoisomerization.
authors.affiliation: Department of Materials Chemistry, Faculty of Science and Technology, Ryukoku University, Seta, Otsu 520-2194, Japan.
authors.forename: Jun-ichiro
authors.initials: J
authors.lastname: Kitai
authors.forename: Takao
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Waka
authors.initials: W
authors.lastname: Uchida
authors.forename: Makoto
authors.initials: M
authors.lastname: Hatakeyama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yokojima
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Kingo
authors.initials: K
authors.lastname: Uchida
mesh_terms: D052176:Azulenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003500:Cyclization; D005030:Ethylenes / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D055668:Photochemical Processes
chemical_list: D052176:Azulenes; D005030:Ethylenes; C005525:azulene