Regulating the excited state chirality to fabricate high-performance-solid-state circularly polarized luminescence...

Area of Science:

• Materials Science
• Photochemistry
• Supramolecular Chemistry

Background:

• Developing solid-state circularly polarized luminescence (CPL) materials is crucial for advanced applications.
• Aggregation-caused quenching and low luminescence dissymmetry factors (g_lum) limit current CPL materials.
• Excited-state chirality regulation is key to overcoming these limitations.

Purpose of the Study:

• To engineer high-performance CPL-active solid-state materials.
• To investigate the switching of excited-state chirality using external stimuli.
• To elucidate the origin of chirality in pyrene-excimer systems.

Main Methods:

• Synthesis of bi-pyrene based chiral emitters.
• Investigation of mechanochromic luminescence properties.
• Solvent fumigation for controlled crystallization.
• Analysis of chiroptical properties in different states (amorphous, crystalline).

Main Results:

• Bi-pyrene based emitters exhibited switchable excited-state chirality.
• Mechanical grinding altered fluorescence color and eliminated CPL.
• Solvent fumigation induced crystallization, activating CPL emission.
• Crystalline state showed chirality amplification in both excited and ground states.

Conclusions:

• A novel method for fabricating high-performance CPL materials was established.
• The study clarifies the chirality origin in pyrene-excimer based luminophores.
• CPL is demonstrated as a valuable probe for excited-state chirality.