title: Self-assembly and aggregate-induced enhanced emission of amphiphilic fluorescence dyes in water and in the solid state.
abstract: 1-Cyano-1,2-bis(biphenyl)ethene (CNBE) derivatives with a hexa(ethylene glycol) group as an amphiphilic side chain were synthesized and the self-assembling character and fluorescence behavior were investigated. The amphiphilic derivatives showed aggregate-induced enhanced emission (AIEE) in water and in the solid state. The fluorescence quantum yield increased as the rigidity of the aggregates increased (i.e., in ethyl acetate<in water<in the solid state). As determined from measurements of fluorescence spectra, fluorescence quantum yields, and fluorescence lifetimes, a key factor for the enhanced emission is suppression of the nonradiative decay process arising from restricted molecular motion. Additionally, the difference in the emission rate constant is not negligible and can be used to interpret the difference in fluorescence quantum yield in water and in the solid state.
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, JST, CREST, Katsura, Nishikyo-ku, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirose
authors.forename: Kenji
authors.initials: K
authors.lastname: Higashiguchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsuda
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D019855:Ethylene Glycol / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D007700:Kinetics; D011789:Quantum Theory; D053838:Scattering, Small Angle; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D005456:Fluorescent Dyes; D014867:Water; D019855:Ethylene Glycol; D019342:Acetic Acid