Potential chiral fluorescent molecular probes based on an α,β-unsaturated ketone for anion detection

A series of potential chiral compounds containing an α,β-unsaturated ketone was developed for anion detection. The interplay of compounds and biological momentous anions (Cl^-, H₂PO₄^-, I^-, AcO^-, HS^-, F^-, and Br^-) was evaluated by UV-vis experiments, fluorescence experiments, and electrochemical tests. By comparison, compound 1 had the best selectivity and compound 5 had the strongest binding ability among the five compounds. And compound 5 had the highest sensitivity to H₂PO₄^- among the measured anions, and it also can be applied to actual samples, the content of H₂PO₄^- tested in the potassium dihydrogen phosphate fertilizer solution reached above 97.5% of the marked content, and the recovery rates were within the range of 98.5-99.1%, attesting that this method was reliable for the test of H₂PO₄^- in fertilizer. Through HRMS titration, circular dichroism and optical rotation experiments, the probable interacted mechanism was proved that the interaction site was the C=C of the α,β-unsaturated ketone structure. In addition, the interacted mechanism was researched from the perspective of chirality. Furthermore, theoretical investigation analysis was introduced to reveal that the roles of molecular frontier orbitals in molecular interplay were determined. Therefore, this series of potential chiral compounds has potential application prospects in anion recognition.