Tailoring Dye Emissions within Metal-Organic Frameworks for Tunable Luminescence and Ratiometric Temperature Sensing

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Luminescence

Background:

• Metal-organic frameworks (MOFs) offer versatile platforms for controlling guest molecule properties.
• Tuning guest luminescence within MOFs is achievable through careful selection of host and guest components.
• Stimuli-responsive luminescence is a key characteristic for advanced sensor applications.

Purpose of the Study:

• To investigate the impact of MOF polarity on dye excimer luminescence.
• To explore the development of MOF-encapsulated dye systems for temperature sensing.
• To demonstrate ratiometric temperature sensing using dual-dye-loaded MOFs.

Main Methods:

• Encapsulation of polar and nonpolar dyes within MOFs of varying polarities.
• Characterization of luminescence properties, including excimer emission and thermal quenching.
• Synthesis and evaluation of a dual-dye MOF (Cz-Ant@ZIF-8) for ratiometric temperature sensing.

Main Results:

• MOF polarity significantly influences dye excimer emission spectra, with higher polarity leading to red-shifted emissions for polar dyes.
• Encapsulated dye excimer emissions exhibit strong thermal quenching.
• The Cz-Ant@ZIF-8 MOF demonstrated effective ratiometric temperature sensing with a sensitivity of 1.55% K⁻¹ over a 278–353 K range.

Conclusions:

• MOFs provide a powerful method for tuning dye luminescence and creating responsive materials.
• The developed MOF system shows promise for sensitive and selective ratiometric thermometry.
• This research highlights the potential of MOF-guest systems in designing novel optical sensors.