biostudies-literatureCao JNatural Science Foundation of Zhejiang ProvinceNational Natural Science Foundation of ChinaNational Key Research and Development Program of China7536-7540https://www.ebi.ac.uk/biostudies/studies/S-EPMC9242012biostudies-literatureUnknown13(25)Pyrrolidine, an important feedstock in the chemical industry, is commonly produced <i>via</i> vapor-phase catalytic ammoniation of tetrahydrofuran (THF). Obtaining pyrrolidine with high purity and low energy cost has extremely high economic and environmental values. Here we offer a rapid and energy-saving method for adsorptive separation of pyrrolidine and THF by using nonporous adaptive crystals of per-ethyl pillar[6]arene (EtP6). EtP6 crystals show a superior preference towards pyrrolidine in 50 : 50 (v/v) pyrrolidine/THF mixture vapor, resulting in rapid separation. The purity of pyrrolidine reaches 95% in 15 min of separation, and after 2 h, the purity is found to be 99.9%. Single-crystal structures demonstrate that the selectivity is based on the stability difference of host-guest structures after uptake of THF or pyrrolidine and non-covalent interactions in the crystals. Besides, EtP6 crystals can be recycled efficiently after the separation process owing to reversible transformations between the guest-free and guest-loaded EtP6.Chemical scienceSeparation of pyrrolidine from tetrahydrofuran by using pillar[6]arene-based nonporous adaptive crystals.PMC924201222035006LD21B0200012021YFA0910100Liu YHuang FJie KCao JLi QZhu HZhu WWang ZWu YfalseSeparation of pyrrolidine from tetrahydrofuran by using pillar[6]arene-based nonporous adaptive crystals.Pyrrolidine, an important feedstock in the chemical industry, is commonly produced <i>via</i> vapor-phase catalytic ammoniation of tetrahydrofuran (THF). Obtaining pyrrolidine with high purity and low energy cost has extremely high economic and environmental values. Here we offer a rapid and energy-saving method for adsorptive separation of pyrrolidine and THF by using nonporous adaptive crystals of per-ethyl pillar[6]arene (EtP6). EtP6 crystals show a superior preference towards pyrrolidine in 50 : 50 (v/v) pyrrolidine/THF mixture vapor, resulting in rapid separation. The purity of pyrrolidine reaches 95% in 15 min of separation, and after 2 h, the purity is found to be 99.9%. Single-crystal structures demonstrate that the selectivity is based on the stability difference of host-guest structures after uptake of THF or pyrrolidine and non-covalent interactions in the crystals. Besides, EtP6 crystals can be recycled efficiently after the separation process owing to reversible transformations between the guest-free and guest-loaded EtP6.2022-01-01T00:00:00Z2022 Jun2026-05-09T23:42:21.331Z2025-04-04T22:12:17.747ZS-EPMC92420123587281410.1039/d2sc02494b