Boron-dipyrromethene based reversible and reusable selective chemosensor for fluoride detection

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Boron-dipyrromethene (BODIPY) dyes are known for their photophysical properties.
• Developing selective sensors for anions like fluoride is crucial for various applications.
• Benzimidazole moieties can modulate the electronic and binding properties of organic molecules.

Purpose of the Study:

• To synthesize and characterize a benzimidazole-substituted BODIPY derivative (BODIPY 1).
• To investigate the anion binding properties of BODIPY 1, focusing on fluoride ion (F-) selectivity.
• To elucidate the sensing mechanism and explore the reversibility of the sensor.

Main Methods:

• Synthesis of BODIPY 1 via condensation of 3,5-diformyl BODIPY with o-phenylenediamine.
• Characterization using spectroscopic techniques (UV-Vis, fluorescence) and X-ray crystallography.
• Anion binding studies involving titration experiments and fluorescence spectroscopy.

Main Results:

• BODIPY 1 exhibited bathochromic shifts, improved quantum yields, and longer lifetimes compared to the parent BODIPY.
• The sensor demonstrated high selectivity and specificity for fluoride ions over other common anions.
• Fluoride binding induced a color change from pink to blue and fluorescence quenching via disruption of hydrogen bonding and photoinduced electron transfer (PET).

Conclusions:

• The synthesized benzimidazole-BODIPY derivative functions as an effective and selective fluoride sensor.
• The sensing mechanism involves structural changes and PET, leading to fluorescence quenching.
• The sensor displays excellent reversibility and reusability over multiple detection cycles.