N,N-Dimethylformamide (DMF)-Promoted SpecificN-Alkylation of Hydroxyl N-Heterocycles with Organohalides: A Direct and Efficient Method for Synthesis of Pyridone Derivatives

Cholesteric Chiral Molecular Tweezer for Rapid Detection of F- in Food Samples

Chiral cholesteric molecular tweezer 7d was synthesized and its influences on changes in the ultraviolet (UV) and fluorescence spectra of various anions were investigated. The results displayed that molecular tweezer 7d selectively recognized F⁻ ions in dimethyl sulfoxide with a detection limit of 5.14 μmol/L, while other anions had little interference. On this basis, a method for the rapid detection of F⁻ ions by host molecular tweezer 7d was established, and the naked-eye detection of F⁻ was realized through the unique yellow color of the complex solution. According to the determination of F⁻ ions in real food samples, it was proved that the established method had good application prospects in F⁻ ion detection.