Selective fluoride ion sensing using novel quinoline chemosensor insights into kinetics and molecular logic gate functions.

CQHC, a novel colorimetric fluorescent sensor, developed for the selective sensing of ions and well characterised, including SC-XRD. It demonstrated selective sensing for Co, Zn, Hg and F using absorbance titration at 420 nm, 446 nm and the binding constants estimated follows the order F > Co > Hg > Zn. On light of this, molecular logic gate was built for CQHC's selective multi-ion detection. However, fluorescence titration analysis revealed that CQHC is solely selective for F ions. This conclusion was validated by H-NMR titration, clearly showed deprotonation occurs from N-H. Fluorescent decay titration, kinetic investigations and computational studies all contributed to the selective sensing of F. According to TD-DFT calculations, added fluoride ion interacts with N-H proton and deprotonates to generate F-H in the excited state.