title: Monofluorination and Trifluoromethylation of BODIPY Dyes for Prolonged Single-Molecule Detection.
abstract: Electrophilic monofluorination with Selectfluor and nucleophilic trifluoromethylation with the Ruppert-Prakesh reagent of dimethyl-, tetramethyl- and pentamethyl-substituted boron dipyrromethenes (BODIPY) are investigated. Monofluorinated dyes are synthesized with low yields (<30%), however trifluoromethyl derivatives are obtained in moderate to high yields (≈40-90%). All compounds are characterized by steady-state and time-resolved fluorescence spectroscopy, the photostability is investigated with fluorescence correlation spectroscopy (FCS) and total internal reflection fluorescence microscopy (TIRF). Monofluorination hardly affects the spectroscopic parameters of the unsubstituted parent compounds, but distinctly enhances the photostability, whereas trifluoromethylation leads to a hypsochromic shift by up to 17 nm in both absorption and emission, slightly enhanced intersystem crossing, and higher photostability. Further development of soft fluorination and trifluoromethylation methods is therefore highly desired.
authors.affiliation: Biophysical Chemistry, Saarland University, Campus Building B22, 66123, Saarbrücken, Germany.
authors.forename: Anh Minh
authors.initials: AM
authors.lastname: Huynh
authors.affiliation: Biophysical Chemistry, Saarland University, Campus Building B22, 66123, Saarbrücken, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Menges
authors.affiliation: Biophysical Chemistry, Saarland University, Campus Building B22, 66123, Saarbrücken, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Vester
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Dier
authors.affiliation: Inorganic and General Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Huch
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University, 66123, Saarbrücken, Germany.
authors.forename: Dietrich A
authors.initials: DA
authors.lastname: Volmer
authors.affiliation: Biophysical Chemistry, Saarland University, Campus Building B22, 66123, Saarbrücken, Germany. g.jung@mx.uni-saarland.de.
authors.forename: Gregor
authors.initials: G
authors.lastname: Jung
mesh_terms: D001896:Boron Compounds / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005456:Fluorescent Dyes / Q000032:analysis / Q000138:chemical synthesis / Q000737:chemistry*; D054879:Halogenation; D008745:Methylation; D008958:Models, Molecular; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D005456:Fluorescent Dyes
keywords: chromophores; dyes/pigments; fluorescence; fluorescence spectroscopy; photophysics