| Popis: |
A novel chemosensor (PK1) has been designed and synthesized in three steps. The binding ability of sensor PK1 with different anions (F ^ -, Cl ^ -, Br ^ -, C_6H_5COO ^ -, CH_3COO ^ -, H_2PO_4 ^ -) in DMSO was evaluated by using ^H NMR, UV-vis and fluorescence spectroscopic techniques. Upon addition of fluoride ion, the NH proton of PK1 disappeared because of deprotonation process. The sensor PK1 exhibited the spectral changes of selectivity to fluoride anion (F ^ -) over other anions, and the new absorption was found at 308 nm due to the internal charge transfer. The fluorescence emission at 415, 438, and 560 nm was quenched due to the complexation of PK1-F-. The stoichiometric complexation was studies by Job’s method as a 1:1 ratio of PK1 with F ^ -. The association constant between PK1 and fluoride was 4.5x10 ^ 4 M ^ in the DMSO solution |
