Indolo[3,2-b]carbazole-containing hypercrosslinked microporous polymer networks for gas storage and separation

Abstract

Two indolo[3,2-b]carbazole-containing hypercrosslinked microporous organic polymers have been successfully synthesized via Friedel-Crafts alkylation reaction in the presence of anhydrous FeCl3. It was found that the polymer InCz-HCP2 produced from the monomer with more reaction active sites shows a higher Brunauer-Emmet-Teller specific surface area up to 1421 m2 g−1 than InCz-HCP1. Both polymers show high isosteric heats of CO2 adsorption over 27 kJ mol−1 because the incorporation of indolo[3,2-b]carbazole unit into the skeleton of the polymers enhanced the binding affinity between the pore wall of the polymer and CO2 molecules. InCz-HCP2 shows a hydrogen uptake ability of 1.68 wt% (77.3 K/1.13 bar) and a carbon dioxide capture capacity of 3.58 mmol g−1 at 273 K/1.13 bar with a good CO2/N2 selectivity of 29:1 at 273 K. With those adsorption properties, these materials could be considered as potential candidates for gas storage and separation.