Supramolecular Mechanoluminescence via Fluorine Interactions.

Area of Science:

• Materials Science
• Organic Chemistry
• Supramolecular Chemistry

Background:

• Mechanoluminescent (ML) materials convert mechanical energy into light without external excitation, offering potential for sustainable optoelectronics and wearables.
• Organic ML systems face challenges balancing brightness, sensitivity, and mechanical durability.
• Existing ML materials often lack the robustness required for practical applications.

Purpose of the Study:

• To overcome the trade-off between brightness, sensitivity, and durability in organic ML materials.
• To develop a supramolecular assembly strategy for enhanced ML performance.
• To create highly sensitive ML stress sensors.

Main Methods:

• Utilized directional fluorine interactions (C─H···F─C and C─F···F─C contacts) to design supramolecular assemblies.
• Investigated structure-property relationships to identify key design criteria for high-performance ML.
• Established a supramolecular platform for Förster resonance energy transfer (FRET) across the visible spectrum.

Main Results:

• Achieved bright and durable ML emission, even under continuous mechanical grinding, by stabilizing molecular packing.
• Demonstrated efficient FRET from ML hosts to ML-inactive luminophores, enabling tunable emission colors (green, yellow, red).
• Fabricated prototype ML stress sensors with high sensitivity, detecting impacts as low as 0.05 N visually.

Conclusions:

• Fluorine-driven supramolecular assembly is a robust strategy for developing advanced organic ML materials.
• The designed materials overcome previous limitations, paving the way for improved optoelectronic and wearable devices.
• The developed platform offers a versatile approach for creating customized ML sensors and light-emitting systems.