title: Minimal Self-Immolative Probe for Multimodal Fluoride Detection.
abstract: Two single-molecule, self-immolative fluoride probes, namely tert-butyldimethylsilyl-protected 2- and 4-difluoromethylphenol, are described. Compared to similar systems previously described, the probes are characterized by a simpler structure and straightforward, two-step preparation. Nevertheless, they allow the detection of fluoride ions at micromolar concentration by the naked eye, UV-vis absorption, and fluorescence. A detailed investigation of the self-immolative reaction reveals that the rate-limiting step is the release of the first fluoride ion from the difluoromethylphenolate intermediate. Moreover, the mutual position of the difluoromethyl- and tert-butyldimethylsilyl-protected residues has a relevant effect on the reactivity. Likely, a CF2H-O hydrogen bond in the 2-isomer increases the reactivity of the silyl ether toward hydrolytic cleavage but also stabilizes the phenolate intermediate, slowing the release of fluoride ions.
authors.affiliation: Università di Padova , Dipartimento di Scienze Chimiche, via Marzolo 1, 35125 Padova, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Gabrielli
authors.affiliation: Università di Padova , Dipartimento di Scienze Chimiche, via Marzolo 1, 35125 Padova, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Mancin
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy; D005459:Fluorides / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006860:Hydrogen Bonding; D015335:Molecular Probes; D066244:Proton Magnetic Resonance Spectroscopy; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D015335:Molecular Probes; D005459:Fluorides