Fluorescent BINOL-based sensor for thorium recognition and a density functional theory investigation

Area of Science:

• Analytical Chemistry
• Inorganic Chemistry
• Materials Science

Background:

• Selective detection of heavy metal ions is crucial for environmental monitoring and safety.
• Fluorescence sensors offer sensitive and rapid detection methods.
• 1,1′-bi-2-naphthol (BINOL) derivatives are versatile scaffolds for designing chemosensors.

Purpose of the Study:

• To develop a novel 1,1′-bi-2-naphthol (BINOL) derivative fluorescence sensor, designated L-1.
• To investigate the sensor's selectivity and sensitivity for thorium ion recognition.
• To elucidate the coordination mechanism between the sensor and metal ions using theoretical calculations.

Main Methods:

• Synthesis of the BINOL derivative fluorescence sensor L-1.
• Fluorescence spectroscopy for metal ion detection.
• Density Functional Theory (DFT) calculations to study coordination effects.

Main Results:

• The L-1 sensor exhibited high selectivity and sensitivity for thorium ion detection.
• A distinct fluorescence quench response was observed upon thorium ion binding.
• DFT calculations confirmed the coordination modes and sites of thorium ions with the L-1 ligand.
• The coordination abilities with Th(4+) and UO2(2+) were evaluated.

Conclusions:

• The novel BINOL derivative L-1 is a highly selective and sensitive fluorescence sensor for thorium ions.
• The fluorescence quenching mechanism is attributed to specific coordination interactions.
• The findings provide a foundation for developing advanced sensors for heavy metal ion analysis.