Three-dimensional nanoporous organic frameworks based on rigid unites

Abstract

With rigid 1,3,5,7-Tetrakis(4-bromophenyl)adamantane (TBPA) and 3,3′,5,5′,7,7′-Hexa(4-bromophenyl)-1,1′-biadamantane (HBPBA) separately coupling with 4,4′-Bisethynylstilene and 4,4′-Bisethynltolan, porous polymers (T1, T2, H1, and H2) were successfully synthesized. The obtained polymers have high surface area (755 m2 g−1) and superior thermal stability (their initial decomposition temperature under N2 condition could reach to 400 °C). In addition, the polymers show ultra-high chemical stability (no apparent decomposition in organic solvents for more than 96 h). At 1.0 bar (273 K), their uptake of CO2, N2, CH4, C2H2 and C2H4 could reach to 11.0 wt%, 1.5 wt%, 6.2 wt% and 7.2 wt%, respectively. Moreover, they also can absorb a large amount of vapor molecules at 298 K, with the largest values up to 232 mg g−1 (benzene), 196 mg g−1 (cyclohexane) and 169 mg g−1 (hexane) when P/P0 = 0.8. The adsorption selectivity for CO2/N2 is 42.6 and for CO2/CH4 is 4.25. These combined properties render the synthesized polymers an attractive candidate as chemical stable adsorbents for practical use in gas storage, gas separation and pollutant vapor adsorption.