Fluoride recognition by a chiral urea receptor linked to a phthalimide chromophore.
The anion chemosensor 1 based on a urea-activated phthalimide with a stereogenic centre was synthesized using an efficient procedure involving a Curtius rearrangement. Its photophysical properties were estimated in several solvents. Sensor 1 detected fluoride with absorption as well as fluorescence changes and was only observable for this case and not for other halides. The appearance of a new CT complex emission at a longer wavelength and no changes in the singlet lifetime of 1 in the presence of fluoride supported a fluorescence static quenching mechanism. 1H-NMR studies, together with theoretical calculations based on DFT methods at the B3lYP/6-31G* level of theory confirmed the formation of a [1-F]- complex through H-bonding interactions rather than receptor deprotonation in the recognition process. Reversibility of this process was observed upon addition of a protic solvent.
Pérez-Ruiz
Raúl
R
Department of Chemistry, Organic Division, University of Cologne, Greinstr. 4, D-50939, Köln, Germany.
Díaz
Yrene
Y
Goldfuss
Bernd
B
Hertel
Dirk
D
Meerholz
Klaus
K
Griesbeck
Axel G
AG
D005459:Fluorides / Q000032:analysis*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010797:Phthalimides / Q000737:chemistry*; D012997:Solvents; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014508:Urea / Q000737:chemistry
D010797:Phthalimides; D012997:Solvents; D014508:Urea; D005459:Fluorides