Polymerization of Polydiacetylene-based Supramolecular Chiral Gel and Its Photoirradiation Regulated CPL

This study presents a co-assembled gel system based on L-histidine methyl ester-functionalized diacetylene (L-HisDA) and pyrene-1-carboxylic acid (1-Py), designed to achieve ultraviolet-induced enhancement of circularly polarized luminescence (CPL). By incorporating the achiral fluorescent molecule 1-Py into the L-HisDA supramolecular gel, the chiral information from the host matrix was successfully transferred to the guest. Systematic characterization revealed that the co-assembled system undergoes a UV‑induced polymerization transition from the blue to the red phase while retaining its original nanoribbon morphology. A distinct CPL signal emerged at 400 nm during photopolymerization, whose intensity increased progressively throughout the phase transition, reaching a maximum in the red phase with dissymmetry factor glum of 0.85 × 10–2. This enhancement effect can be attributed to the amplification and transfer of chirality within the co-assembled gel during UV irradiation. This work provides a novel co-assembly strategy for developing photo-responsive CPL-active materials.