Spontaneous amino-yne click polymerization enabled by pyridinium-activated alkynes toward p-π conjugated ionic polymers

Abstract

The p-π conjugated polymers have garnered considerable interests owing to their distinctive electronic structures, which arise from the interaction between p orbitals and π electrons. Currently, the p-π conjugated polymers with charged side chains have been extensively studied, those featuring charged backbones are rare due to the synthetic difficulties. In this work, we developed a spontaneous amino-yne click polymerization utilizing pyridinium-activated alkyne and aromatic primary amine monomers, enabling the efficient synthesis of p-π conjugated ionic polymers with high weight-average molecular weights (Mw, up to 44100) and excellent yields (up to 98%). The resultant polymers are emissive, but demonstrate remarkable photothermal properties. Upon irradiation with an 808 nm laser (1.0 W/cm²), the polymer powders rapidly reach temperatures as high as 310 °C within 20 s, the highest reported value for polymeric photothermal materials while maintaining outstanding photostability. Additionally, these polymers function as effective electrode materials via a four-electron-transfer process, retaining 85.2% of their capacity after 100 charge-discharge cycles. This work not only establishes a novel pyridinium-activated alkyne-based spontaneous amino-yne click polymerization but also provides a versatile strategy for designing p-π conjugated ionic polymers with broad application potentials.