title: Photochemical behavior of some p-styrylstilbenes and related compounds: spectral properties and photoisomerization in solution and in solid state.
abstract: The spectral properties and Z,E-photoisomerizations of three 4-styrylstilbenes, a 4,4'-bis(P-methylstyryl)benzene and a 4,4'-distyrylstilbene were investigated in solution and in the solid state. Some notable features of the absorption and fluorescence spectra due to the structures and the phases (solution or solid) were observed, especially the Stokes shifts. Interesting photochemical behaviors in solution and in the solid state were also found. While the (E,Z)-4-styrylstilbenes undergo a one-way photoisomerization to their E,E-isomers with almost equal rates in solution, their quantum yields in the solid state decrease with increasing substituent size at the terminal aromatic rings. On the other hand, the 4,4'-bis(beta-methylstyryl)benzene undergoes a mutual photoisomerization in solution, but its E,Z-isomer isomerizes in a one-way manner to the E,E-isomer in the solid state. Additionally, the (Z,E,Z)-4,4'-styrylstilbene was found to undergo a one-way photoisomerization to the E,E,E-isomer via the E,E,Z-isomer in solution and the crystalline E,E,Z-isomer to the E,E,E-isomer in the solid state.
authors.affiliation: Department of Chemistry, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Fengqiang
authors.forename: Jiro
authors.initials: J
authors.lastname: Motoyoshiya
authors.forename: Junji
authors.initials: J
authors.lastname: Nakamura
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nishii
authors.forename: Hiromu
authors.initials: H
authors.lastname: Aoyama
mesh_terms: D007536:Isomerism; D010777:Photochemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013267:Stilbenes / Q000737:chemistry* / Q000528:radiation effects*
chemical_list: D012996:Solutions; D013267:Stilbenes