Versatile click functionalization of poly(1,2,3-triazolium ionic liquid)s

Abstract

Although poly(ionic liquid)s (PILs) are rapidly gaining attention in the fields of materials science and alternative energies, methods for their functionalization have only been scarcely addressed so far. Herein, we present an efficient and broad in scope strategy for the functionalization of 1,2,3-triazolium-based PILs. The principle of this general concept is illustrated using a poly(1,2,3-triazole) template obtained by click chemistry step growth polymerization. Alkylation of the 1,2,3-triazole groups by 5-iodo-1-pentyne affords 1,2,3-triazolium iodides having a tunable amount of pendant alkyne functionalities. Further click coupling of (co)polymers having different contents of alkyne groups is demonstrated using several model azides and characterization by NMR and UV–Vis spectroscopies. Since 1,2,3-triazole groups are generated after click coupling, this sequential quaternization/CuAAC ligation approach has the potential to be further extended to the perpetual multi-functionalization of polymer templates or to the synthesis of ion conducting oligomers.