Two Different Emission-Wavelength Fluorescent Probes for Aluminum Ion based on Tunable Fluorophores in Aqueous Media

Two simply and highly selective aluminium ion fluorescent probes based on 4-aminoantipyrine derivate have been successfully synthesized and systemically characterized, The investigation of absorption and emission spectra revealed that the compounds exhibited highly selective fluorescence behaviours toward Al3+ in aqueous media and showed differential fluorescent emission peaks corresponding to blue and green. which resulted from different fluorophores, and the fluorescence process is attributed to the Photoinduced Electron Transfer (PET) mechanism, In addition, the association constants between sensors L1 and L2 with aluminum ion are 1.58 × 106 M−1 and 8.72 × 106 M−1, respectively, which were obtained by fluorescent titration experiments. Moreover, the binding site of sensors with Al3+ were determined by 1HNMR titration experiments.