Synthesis of Functional Hyperbranched Poly(methyltriazolylcarboxylate)s by Catalyst-free Click Polymerization of Butynoates and Azides

Azide-alkyne click polymerization has become a powerful tool for polymer synthesis.However,the click polymerization between internal alkynes and azides is rarely utilized to prepare functional polymers.In this work,the polymerization reactions of activated internal alkyne monomers of tris(2-butynoate)s(1)with tetraphenylethene-containing diazides(2)were performed in dimethylformamide(DMF)under simple heating,affording four hyperbranched poly(methyltriazolylcarboxylate)s(hb-PMTCs)with high molecular weights(A4W up to 2.4 x 104)and regioregularities(up to 83.9%)in good yields.The hb-PMTCs are soluble in common organic solvents,and thermally stable with 5%weight loss temperatures up to 400℃.They are non-emissive in dilute solution,but become highly emissive in aggregated state,exhibiting aggregationinduced emission characteristics.The polymers can generate fluorescent photopatterns with high resolution,and can work as fluorescent sensors to detect nitroaromatic explosive with high sensitivity.