Accelerated Solvent- and Catalyst-Free Synthesis of 1,2,3-Triazolium-Based Poly(Ionic Liquid)s
Résumé
A straightforward and expeditious monotopic approach for the preparation of 1,2,3-triazo- lium-based poly(ionic liquids) (TPILs) is reported. It is based on the solvent- and catalyst-free polyaddition of an α-azide-ω-alkyne monomer in the presence of methyl iodide or N -methyl bis[(trifl uoromethyl)sulfonyl]imide alkylating agents. Poly(1,2,3-triazole)s generated in bulk or by thermal azide–alkyne cycloaddition (AAC) are quaternized in-situ to afford TPILs composed of 1,3,4- and 1,3,5-trisubsti- tuted 1,2,3-triazolium units. The physical and ion-conducting properties of the prepared samples are compared with the TPILs composed solely of 1,3,4-trisubstituted 1,2,3-triazolium units obtained through a multistep approach involving copper(I)- catalyzed AAC polyaddition, quaternization of the 1,2,3-tria- zole groups, and anion metathesis. TPILs obtained through the monotopic approach display thermal stabilities and ionic con- ductivities comparable to their pure regioisomeric analogues.