title: The effects of spacer length on the fluorescence quantum yields of the benzofurazan compounds bearing a donor-acceptor system.
abstract: We studied the effects of spacer length on the fluorescence quantum yields (Phi) of photoinduced electron transfer (PET) reagents, using nitrobenzoxadiazole (NBD) derivatives that have the -NMe2 moiety and NBD-NH- fluorophore as electron donor (D) and electron acceptor (A), respectively. The Phi values were reduced as the spacer length became shorter (n < or = 4; n is the number of methylene units of the spacer) and the fluorescence recovered by suppression of the PET process. It is necessary for the useful PET reagents to link D and A with a short spacer to obtain a difference in the Phi values between fluorescent "off-state" and "on-state".
authors.affiliation: Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Onoda
authors.forename: Seiichi
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Santa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Imai
mesh_terms: D001583:Benzoxazoles / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry* / Q000494:pharmacology; D004583:Electrons; D005453:Fluorescence; D007700:Kinetics; D010084:Oxidation-Reduction; D010777:Photochemistry; D013329:Structure-Activity Relationship
chemical_list: D001583:Benzoxazoles; D003432:Cross-Linking Reagents; C020160:benzofurazan