Tunable Circularly Polarized Luminescence from Polyether‐Based Liquid Crystalline Polymer

Abstract Circularly polarized luminescence (CPL) materials have garnered considerable attention for applications in optical data storage, anti‐counterfeiting, and photonic devices. However, precisely controlling over chirality and emissive properties of chiral luminescent polymers remains challenging. Herein, this work presents a series of polyether‐based chiral luminescent liquid crystalline copolymers (LCPs), denoted Cy x Ch y , synthesized via organocatalyzed ring‐opening copolymerization of epoxides bearing cyanostilbene (Cy) and cholesterol (Ch) units. The resulting polymers exhibit controlled molar masses, narrow distributions, and excellent thermal stability. The liquid crystal phase transitions exhibit tunable behavior dependent on Ch content, progressing sequentially from a chiral nematic phase in Cy 4 Ch 1 and Cy 3 Ch 2 to a chiral smectic phase in Cy 2 Ch 3 , and ultimately to a smectic phase in Cy 1 Ch 4 . Notably, efficient π–π interactions of cyanostilbene moieties confer pronounced photoluminescence, with emission shifting to shorter wavelengths as the proportion of Cy decreases. Simultaneously, the chiral cholesterol segments introduce strong CPL signals, achieving |glum| values up to 0.28 for specific compositions. Remarkably, a CPL signal inversion is observed at a 4:1 Cy:Ch molar ratio due to selective Bragg reflection within the self‐assembled copolymer matrix. These results demonstrate a versatile pathway to advanced polyether‐based LCPs with robust CPL activity, heralding new opportunities for high‐performance optoelectronic and photonic technologies.