Tunable and Switchable Control of Luminescence through Multiple Physical Stimulations in Aggregation-Based...

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Photophysics

Background:

• Naphthalimide derivatives are known for their luminescent properties.
• Controlling luminescence through external stimuli is crucial for advanced materials.
• Aggregation-induced emission and mechanochromism are key phenomena in smart materials.

Purpose of the Study:

• To investigate the tunable luminescence of naphthalimide-based organogelators.
• To achieve switchable color and fluorescence control using physical stimuli.
• To explore applications in sensing and advanced material design.

Main Methods:

• Synthesis of naphthalimide-based organogelators (N3-N7).
• Induction of gelation and mechanochromism using sonication and grinding.
• Characterization of photophysical properties (emission wavelength, intensity) under various stimuli.
• Application of mechanochromic properties for mechanical pressure sensing.

Main Results:

• Sonication triggered reversible gelation, shifting emission color and quenching fluorescence.
• Grinding solid-state xerogels induced mechanochromism (color and emission changes).
• One xerogel (N3) quantitatively sensed mechanical pressure from 2-40 MPa via fluorescence changes.
• Stimuli-induced changes in aggregation and molecular arrangement affected internal charge transfer (ICT) and photophysical properties.

Conclusions:

• Developed a strategy for tunable and switchable luminescence control using non-chemical stimuli.
• Demonstrated the potential of naphthalimide-based organogelators in aggregation-based systems.
• Highlighted the influence of molecular structure and solvent on stimuli-responsive luminescence.
• Showcased a novel application of gelation assembly for mechanical sensing.