Precise Synthesis of Structurally Diverse Aggregation-Induced Emission-Active Polyacrylates by Cu(0)-Catalyzed SET-LRP with Macromolecular Structure-Correlated Emission

Abstract

The rational design and precise synthesis of aggregation-induced emission (AIE) active polymers with diverse macromolecular structures are crucial to their applications in various fields. Herein, four tetraphenylethylene (TPE) bromopropionate initiators with the number of initiation sites of n = 1−4 were synthesized for the first time and applied in the Cu(0)-mediated single-electron transfer living radical polymerization (SET-LRP) of methyl acrylate (MA) and tert-butyl acrylate (tBA). Well-controlled polymerization and high chainend fidelity were confirmed by 1 H NMR and GPC. The produced polymers had diverse topology (linear/star) and the location of TPE moiety (chain-end/midchain/core), which were all precisely dictated by initiator structure. The macromolecular structure had a remarkable effect on the AIE properties of TPE-(PMA) n in THF/H 2 O mixtures and TPE-(PAA) n (obtained after deprotecting tert-butyl groups from TPE-(PtBA) n ) in the B-R buffer solutions of different pH values. The fundamental insights gained into the macromolecular structure−AIE property correlation in our work are important for the design of AIE-active polymer-based functional materials.

Multi Stimuli-Responsive Aggregation-Induced Emission Active Polymer Platform Based on Tetraphenylethylene-Appended Maleic Anhydride Terpolymers

“…It is striking that the three TPE-appended maleic acid terpolymers exhibited a widely varied response to Ca 2+ . hPTSM-39 displayed the largest dynamic range (86), which was much higher that of hPTVM-39 (17) and hPTSM-39 (15). This is consistent with the highest chain rigidity and strongest aromatic ring-involved intramolecular interactions of hPTSM-39.…”

“…Recently, aggregation-induced emission luminogens (AIEgens) have been utilized in developing stimuli-responsive AIE-active polymer systems. − Owing to their inherent high sensitivity to the aggregated state dictated by their surrounding environment, AIEgens play the dual roles of “stimuli acceptor” and “signaling module” in the system. This often gives rise to intriguing stimuli-responsive fluorescence performance, contrasting to the case of traditional fluorophores with the troublesome aggregation-caused quenching effect.…”

Aggregation-Induced Emission Polymers via Reversible-Deactivation Radical Polymerization

“…A comparison study was performed between pristine DOX solution as the control and TPE-PEGA-Hyd-DOX solutions at the same concentration, where drug release reached only 10% after 96 hours under normal cell conditions compared with 40% after 24 hours under cancer cell conditions helps confirmed that conjugation of DOX to the drug carrier controls the release of DOX and protects normal cells against DOX. Many other studies also employed the Cu(0)-RDRP methods to synthesize AIE polymers such as Cu(0)-catalyzed SET-LRP reported by Wang, Yang and co-workers for the study of multi-arm star polymers with TPE-functionalized core, [183] and the study of through-space charge-transfer thermally activated delayed fluorescence (TSCT-TADF) phenomenon using AIE-functionalized monomers. [184][185][186] NMP can also be used for the synthesis of AIE polymers with a unique morphology as demonstrated by Nicolas and co-workers in 2017, whom employed carbodiimide chemistry to link 4-(N -methylpiperazine)-1,8-naphthalimide-based AIE dye, [187] with AMA-SG1 alkoxyamine, yielding Napht-AMA-SG1 in 82% yield via the grafting from or 'drug-initiated' method.…”

Tailoring Polymerization Controllability and Dispersity Through a Photoswitchable Catalyst Strategy

“…and easily removing catalyst. [43][44][45][46][47] Notably, SET-LRP is highly sensitive for monomers, initiators, and ligands. The matching of initiators and ligands affects the controllability SET-LRP of methyl methacrylate (MMA).…”

“…Single‐electron transfer mediated living radical polymerization (SET‐LRP) was selected to validate our hypothesis due to its unique advantages, such as high end‐group fidelity, fast polymerization rate, and easily removing catalyst. [ 43–47 ] Notably, SET‐LRP is highly sensitive for monomers, initiators, and ligands. The matching of initiators and ligands affects the controllability SET‐LRP of methyl methacrylate (MMA).…”