Clustering-triggered Emission Liquid Crystalline Polymer Bearing Cholesterol: Tunable Circularly Polarized Luminescence and Room-Temperature Phosphorescence.

Circularly polarized luminescence (CPL) materials with clustering-triggered emission (CTE) characteristic have gradually attracted attention for their unique photo-physical properties. However, the majority of reported clusteroluminogens lack chirality and exhibit heterogeneity, making it challenging to achieve a well-defined helical structure necessary for efficient CPL with high dissymmetry factor (g lum ). In this article, we constructed chiral liquid crystals to obtain CTE based CPL materials with high g lum values. We designed and synthesized side chain liquid crystal polymer PM6Chol bearing cholesterol clusteroluminogens. PM6Chol coated film and PM6Chol thermal treated film were also successfully prepared by different film-forming methods. Both the two films inherited the CTE characteristic of cholesterol and showed excitation wavelength-dependent luminescent behavior. While, the two polymer films exhibited different liquid crystal phase structures, with PM6Chol coated film being a chiral bilayer smectic C phase and PM6Chol thermal treated film being an achiral bilayer smectic A phase. Attributed to helical arrangement of cholesterol, PM6Chol coated film emitted efficient CPL with g lum values up to 1.0 × 10 -1 . For PM6Chol thermal treated film, no CPL signal was detected due to the absence of helical structure. However, it showed obvious room temperature phosphorescence with 2.0 s afterglow and 23.9 ms lifetime. This article is protected by copyright. All rights reserved.