title: Fluorescence Properties of Diphenylthiazolo[4,5-b]pyrazines Tuned by Donor-Acceptor Substituent Effects.
abstract: Fluorescence properties of 2,6- and 2,5-diphenylthiazolo[4,5-b]pyrazine (TPy) derivatives having an electron-donating substituent (methoxy and dimethylamino) on the 6- and 5-phenyl groups were studied. It was found that 2,6-diphenyl derivatives fluoresce more efficiently than 2,5-diphenyl derivatives. Furthermore, a 2,6-diphenyl derivative having an additional cyano group on the 2-phenyl ring was an excellent fluorophore showing a wide solvatochromism with great fluorescence yields. Based on the obtained spectroscopic data and mechanistic explanations concerning the substituent effects on the fluorescence properties, useful information on designing new TPy fluorophores is provided.
authors.affiliation: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Nakagawa
authors.affiliation: Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamaji
authors.affiliation: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors.forename: Shojiro
authors.initials: S
authors.lastname: Maki
authors.affiliation: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors.forename: Haruki
authors.initials: H
authors.lastname: Niwa
authors.affiliation: Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirano
mesh_terms: D011719:Pyrazines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D011719:Pyrazines