Solvent-Dependent Fluorescence Properties of CH₂-bis(BODIPY)s

Area of Science:

• Organic Chemistry
• Supramolecular Chemistry
• Analytical Chemistry

Background:

• Organic dyes with environment-sensitive fluorescence are valuable analytical agents.
• BODIPY dimers (bis(BODIPY)) exhibit fluorescence sensitive to solvent polarity.

Purpose of the Study:

• To investigate the fluorescence sensitivity of novel CH2-bis(BODIPY) dyes to polar solvents.
• To elucidate the mechanism of fluorescence quenching and the formation of supramolecular complexes.

Main Methods:

• Steady-state absorption and fluorescence spectroscopy
• Time-resolved fluorescence spectroscopy
• Computational modeling

Main Results:

• CH2-bis(BODIPY) dyes (1-3) show intense fluorescence in nonpolar solvents, dramatically quenched in polar solvents (acetone, DMF, DMSO).
• Fluorescence quenching is attributed to specific solvation by electron-donating molecules, forming stable supramolecular CH2-bis(BODIPY)·2Solv complexes.
• The formation, composition, structure, and stability of these supramolecular complexes were substantiated.

Conclusions:

• CH2-bis(BODIPY)s exhibit significant fluorescence changes in response to polar solvents.
• The formation of stable supramolecular complexes drives the fluorescence quenching mechanism.
• These findings highlight the potential of CH2-bis(BODIPY)s as fluorescent probes for detecting toxic N/O-containing compounds.