Ionic quaternary ammonium-triazole polymers as efficient single-component catalysts for CO2 conversion

Ionic organic polymers with halide counterions have been investigated as effective and reusable single- component, heterogeneous catalysts for the cycloaddition of COQ and epoxides to form cyclic carbonates. In this study, we synthesized three new ionic polymers featuring quaternary ammonium-triazole functional groups with iodide counterions. Copper-catalyzed azide-alkyne cycloaddition (CuAAC) between tetrapropargylammonium bromide and various diazide compounds (N3-Ar-N3), where Ar represents 1,4-xylene, 1,5-naphthalene, and 4,4 '-phenylbenzamide followed by halide exchange, afforded the organic polymers QAP1-3, respectively. The formation of triazole moieties and the disappearance of azide functional groups were confirmed by 13 C CP/ MAS NMR and FT-IR spectroscopy, respectively. CO2 sorption studies showed reduced adsorption capacities compared to neutral amine analogs. The xylene-linked polymer ( QAP1 ) exhibited the highest catalytic efficiency for CO2/epoxide cycloaddition, achieving high conversion and selectivity under 10 atm CO2 at 120 degrees C. Reusability study showed that QAP1 could be reused for four cycles with minimal loss in activity, though some thermal decomposition of quaternary ammonium groups was observed in solution.