Selective and colorimetric fluoride anion chemosensor based on s-tetrazines

Area of Science:

• Analytical Chemistry
• Supramolecular Chemistry
• Organic Chemistry

Background:

• s-Tetrazines are nitrogen-rich heterocyclic compounds with unique electronic properties.
• Selective and sensitive detection of fluoride anions remains a significant challenge in various fields.
• Colorimetric chemosensors offer a simple and visual method for analyte detection.

Purpose of the Study:

• To develop and investigate s-tetrazine derivatives as selective colorimetric chemosensors for fluoride anions.
• To elucidate the mechanism of fluoride recognition by tetrazine receptors.
• To assess the sensor's performance in terms of selectivity and tolerance to water.

Main Methods:

• Synthesis and characterization of s-tetrazine derivatives.
• Spectrophotometric titration to study the interaction between tetrazines and fluoride.
• Investigation of supramolecular interactions, including anion-π and charge/electron transfer.
• Evaluation of selectivity against common anions and tolerance to water in DMSO.

Main Results:

• s-Tetrazines exhibit selective colorimetric sensing of fluoride anions.
• A distinct color change from red to green was observed upon fluoride binding.
• The sensing mechanism involves anion-π interaction and electron transfer, generating a tetrazine radical anion.
• The sensor demonstrated excellent selectivity for fluoride over other anions and tolerance to water (9:1 DMSO-H2O).

Conclusions:

• s-Tetrazine derivatives are effective colorimetric chemosensors for fluoride detection.
• The observed color change provides a visual indicator for the presence of fluoride.
• The developed sensor shows high selectivity and robustness, making it suitable for practical applications.