Abstract
The present work describes the synthesis and comparative investigations of Cu2+ and Cu+ ions sensing properties of two novel π-extended coumarin-Schiff base-derived electronically distinct fluorescent probes (4 and 5). Due to the additional electron donating group substituent (-NEt2) close proximate to the binding site of Schiff base in probe 5, it exhibits distinct electronic properties compared to probe 4. Our studies indicate that probe 5 displays efficient and highly selective fluorescence quenching behaviors with Cu2+ and Cu+ ions compared to other competitive metal ions (Ca2+, Mg2+, Al3+, Hg2+, Pb2+, Cd2+, Mn2+, Co2+, Ni2+, Fe2+, Fe3+, Cr3+ and Zn2+). In our studies, Job's plot experiments revealed that the binding stoichiometry of the ligand-Cu2+ was 1:1 for both probes. The limit of detection (LOD) of 2.35 × 10–5 M and 1.56 × 10–5 M were obtained for the probes 4 and 5, respectively. Further, the Stren-Volmer equation has been used to calculate the binding abilities of probes with Cu2+ ions; it reveals the binding constant of 6.70 × 104 M-1 and 22.0 × 104 M-1 for probes 4 and 5, respectively. Also, in the present studies, our DFT computed results were comparatively presented to understand the electronic parameters (HOMO-LUMO energy band gaps, ESP and Mulliken atomic charge distribution) of compound 1, probes 4 and 5. We anticipate that the developed probes can be used to analyze Cu2+ and Cu+ ions in environmental and biological samples.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call