Facile Synthesis of Functional Poly(methyltriazolylcarboxylate)s by Solvent- and Catalyst-free Butynoate-Azide Polycycloaddition

Abstract

The copper-catalyzed and metal-free azide-alkyne click polymerizations have become efficient tools for polymer synthesis. However, the 1,3-dipolar polycycloadditions between internal alkynes and azides are rarely employed to construct functional polymers. Herein, the polycycloadditions of dibutynoate (1) and tetraphenylethene-containing diazides (2) were carried out at 100 °C for 12 h under solvent- and catalyst-free conditions, producing soluble poly(methyltriazolylcarboxylate)s (PMTCs) with high molecular weights in high yields. The resultant polymers were thermally stable with 5% weight loss temperatures up to 377 °C. The PMTCs showed aggregation-induced emission (AIE) properties. They could work as fluorescent sensors for detecting explosive with high sensitivity, and generate two-dimensional fluorescent photopatterns with high resolution. Furthermore, their triazolium salts could be utilized for cell-imaging applications.