title: Disabling photoinduced electron transfer in 4,4-difluoro-8(-4'-hydroxyphenyl)-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene by phosphorylation.
abstract: The synthesis and photophysical characterization of the phosphorylated Bodipy dye 5 are reported and compared to those of its hydroxyphenyl counterpart 1. Conversion of the latter by three methods of phosphorylation yields the strongly fluorescent dye 5 which exhibits similar steady-state spectra like 1 but an approximately five times prolonged fluorescence lifetime tau(Fl). We attribute this distinct change from tau(Fl) = 0.7 ns for 1 to tau(Fl) = 3.7 ns for 5 to the suppression of photoinduced electron transfer in 5. This photochemical reaction was previously held responsible for fluorescence quenching in 1. Fluorescence correlation spectroscopy reveals that 5 can be detected by single-molecule methods and that uncaging of phosphate in 5 is a minor problem.
authors.affiliation: Biophysical Chemistry, Saarland University, Saarbruecken, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Jacob
authors.forename: Alexander
authors.initials: A
authors.lastname: Schmitt
authors.forename: Gregor
authors.initials: G
authors.lastname: Jung
mesh_terms: D001896:Boron Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D004583:Electrons; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D010766:Phosphorylation; D010777:Photochemistry; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013055:Spectrophotometry, Infrared
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D005456:Fluorescent Dyes