Synthesis, Photophysical Properties, and Practical Hg(II)-Sensing Applications of a Rigidified Phenolo-Merocyanine...

Area of Science:

• Organic chemistry
• Photophysics
• Analytical chemistry

Background:

• Scaffold rigidification enhances photophysical properties of organic fluorophores.
• Developing high-performance phenolic fluorophores is crucial for advanced imaging and sensing applications.

Purpose of the Study:

• To synthesize a conformationally restrained analog of Brooker's merocyanine for improved fluorescence.
• To develop novel phenolic fluorophores with enhanced yellow emission and photostability.
• To create sensitive chemodosimeters for mercuric ion detection.

Main Methods:

• Acid-catalyzed domino double cyclization for synthesizing fluorescent phenol KR306.
• Comprehensive photophysical studies to evaluate optical properties.
• Modification of the hydroxyl group to create thiophosphinate and thiophosphonate esters for sensing applications.

Main Results:

• KR306 exhibits outstanding optical properties: high brightness (71,500 M⁻¹ cm⁻¹) and yellow emission (λem ≈ 560 nm) at neutral pH.
• Modified KR306 derivatives function as effective chromo-fluorogenic chemodosimeters for mercuric ions (Hg(II)).
• The thiophosphinate derivative 5 demonstrated superior sensing performance and enabled naked-eye detection of Hg(II) in kefir grains.

Conclusions:

• Scaffold rigidification is an effective strategy for developing high-performance organic fluorophores.
• KR306 and its derivatives offer promising tools for sensitive Hg(II) detection in aqueous and biological environments.
• The developed chemodosimeters show potential for practical applications in sensing and diagnostics.