Synthesis of Functionalized 1-cyclooctyl-3-methyl-1,2,3-triazolium via click chemistry and their polymerization by ROMP

Abstract

This paper describes the synthesis of a new ionic liquid (IL) monomer of 5-substituted cyclooctene 1,2,3-triazolium iodides salt via click chemistry, and an anion exchange reaction with two different counteranions: bis(trifluoromethylsulfonyl)imide [N(SO2CF3)2]−(NTf2−), and hexafluorophosphate ([PF6]−). The structural properties of all monomers were determined by MALDI-TOF-MS, (1H; 13C; 19F;)NMR spectroscopy. 1,2,3-triazolium-based poly(ionic liquid)s (TPILs) with the pendant triazolium moieties were also synthesized by Ring-Opening Metathesis Polymerization (ROMP) using Grubbs second generation (Grubbs II) ruthenium as a catalyst with good control during the polymerization process and gave viscous solutions. The Synthesis of the polymers (TPILs) was confirmed by 1HNMR spectroscopy. The thermal properties were characterized by thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The thermal stability of monomers was found to be high (∼286°C). Furthermore, monomers salts with [NTf2−] have low melting points below 100°C (25-99°C), and their TPILs are viscous liquids at room temperature, with a low glass transition temperature (Tg = -23°C). This result suggests that the 5-substituted cyclooctene 1,2,3-triazolium ionic liquid monomer offers high chain flexibility to the resulting polymers (TPILs). Hence this new class of IL monomer and TPILs may be potentially useful in electrolyte membrane applications.