Bimodal calix[2]triazole[2]arene fluorescent ionophore

Area of Science:

• Supramolecular Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Calixarenes are versatile macrocyclic hosts with tunable properties.
• Pyrene derivatives are widely used as fluorescent probes.
• Developing selective metal ion sensors is crucial for environmental and biological monitoring.

Purpose of the Study:

• To synthesize a pyrene-appended calix[2]triazole[2]arene for bimodal metal ion sensing.
• To investigate the selective detection of specific metal ions using fluorescence.
• To elucidate the sensing mechanism through experimental and theoretical studies.

Main Methods:

• Synthesis of a pyrene-appended calix[2]triazole[2]arene.
• Fluorescence spectroscopy for metal ion sensing (monomeric and excimeric emissions).
• Density Functional Theory (DFT) calculations for mechanistic insights.

Main Results:

• The synthesized probe exhibited selective enhanced monomeric emission for Zn(2+) and Cd(2+) (13-20-fold increase).
• The probe showed selective enhanced excimeric emission for Fe(2+) (10-fold increase) over other metal ions, including Fe(3+).
• DFT calculations supported the experimental observations and explained the bimodal sensing behavior.

Conclusions:

• A novel calixarene-based fluorescent probe with bimodal sensing capabilities for metal ions was successfully developed.
• The probe demonstrates high selectivity for Zn(2+)/Cd(2+) and Fe(2+) based on distinct fluorescence emission modes.
• This work offers a promising platform for developing advanced chemosensors for specific metal ion detection.