Multi-color tunable circularly polarized luminescence in one single AIE system

Area of Science:

• Materials Science
• Organic Chemistry
• Photophysics

Background:

• Circularly polarized luminescence (CPL) materials are crucial for advanced optical applications.
• Achieving both high luminescence dissymmetry factor (g_lum) and multi-color tunability in a single CPL-emitting component remains a significant challenge.
• Existing multi-color CPL systems often rely on multiple organic dyes, limiting their integration and efficiency.

Purpose of the Study:

• To design and synthesize a novel aggregation-induced emission (AIE) fluorophore capable of exhibiting multi-color tunable CPL with a high g_lum.
• To investigate the self-assembly behavior of the designed AIE fluorophore and its influence on CPL properties.
• To demonstrate a facile method for achieving multi-color CPL emission from a single molecular component through chemical stimuli.

Main Methods:

• Synthesis of a pyridine-functionalized cyanostilbene derivative attached to a chiral unit, designed as an AIE fluorophore.
• Characterization of the self-assembly behavior, including nanohelix formation, and the formation of gel and xerogel films.
• Spectroscopic analysis of CPL properties, including g_lum values and emission spectra, under different conditions (e.g., pyridine protonation).

Main Results:

• The synthesized AIE fluorophore self-assembles into nanohelices, forming gels and xerogel films.
• Blue CPL emission was observed with high g_lum values (up to -3.0 × 10^-2) in the assembled structures.
• Protonation of the pyridine moiety induced a significant red-shift in CPL emission from 480 nm to 530 nm, covering blue to orange colors while maintaining a constant g_lum.

Conclusions:

• A single-component AIE fluorophore has been successfully developed to achieve multi-color tunable CPL with high g_lum.
• The self-assembly and chemical modification (protonation) strategies provide a versatile platform for controlling CPL properties.
• This work presents a promising and straightforward approach for fabricating advanced multi-color CPL materials for various optoelectronic applications.