Molecular Cursor Caliper: A Fluorescent Sensor for Dicarboxylate Dianions.

Area of Science:

• Supramolecular Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Developing selective and sensitive fluorescent chemosensors is crucial for detecting various anions.
• Vibration-induced emission (VIE) materials offer unique photophysical properties for sensing applications.
• Calixpyrrole derivatives are effective hosts for anion recognition via hydrogen bonding.

Purpose of the Study:

• To develop a single fluorescent probe for sensing diverse dicarboxylate anions.
• To investigate the mechanism of fluorescence sensing based on host-guest complexation.
• To explore the potential of combining VIE properties with supramolecular recognition for tunable chemosensors.

Main Methods:

• Synthesis of the bis-calix[4]pyrrole-appended phenazine probe (DPAC-bisC4P).
• Fluorescence titration studies in acetonitrile with various dicarboxylate anions.
• Analysis of emission spectral changes and chromaticity outputs.

Main Results:

• DPAC-bisC4P successfully detected aromatic and linear saturated dicarboxylate anions.
• Anion binding induced a blue-shift in the phenazine core's emission.
• Distinct chromaticity outputs were observed for different dicarboxylates, enabling visualization.
• The probe formed pseudomacrocyclic complexes with dicarboxylates via hydrogen bonding.

Conclusions:

• The DPAC-bisC4P probe acts as a rudimentary sensor for dicarboxylate anions.
• The system demonstrates effective fluorescence tuning based on binding events.
• Combining tunable VIE cores with noncovalent interactions is a promising strategy for developing advanced fluorescent chemosensors.