Spring Lock: Constructing Cluster Emitters with Colorful TADF from Non-Conjugated Polymaleimide Helical Chains

Abstract

Non-conjugated luminescent polymers have received much attention due to their excellent flexibility, processability, and biocompatibility. However, the single emission color and low solid-state luminescence efficiency restrict their further development. Herein, by introducing carboxyl-terminated alkyl chains on the rigid and helical polymaleimide backbone, a series of non-conjugated luminescent polymers are designed and synthesized. Due to the “spring lock” formed by the synergism of scalable helical main chains and flexible alkyl side chains, these polymers exhibit effective cluster luminescence with thermally activated delayed fluorescence (TADF) property, thereby significantly improving the solid-state luminescence efficiency with the quantum yield up to 59.6%. The TADF emission wavelengths of the polymer powders can be tuned from 498 to 639 nm through changing reaction solvents, because the conformation of helical chains forming clusters is sensitive to solvent polarity. Interestingly, metal ions can induce the polymers to construct self-repairing cluster luminescence gels, which show excellent potential applications in ammonia detection and information encryption. This work not only provides an effective design strategy for the colorful cluster luminescence with high-efficiency TADF, but also further reveals the cluster luminescence mechanism and enlightens the promising applications of cluster luminescent gels.