A Hydrogen-Bonded yet Hydrophobic Porous Molecular Crystal for Molecular-Sieving-like Separation of Butane and Isobutane.

Porous molecular crystals sustained by hydrogen bonds and/or weaker connections are an intriguing type of adsorbents, but they rarely demonstrate efficient adsorptive separation because of poor structural robustness and tailorability. Herein, we report a porous molecular crystal based on hydrogen-bonded cyclic dinuclear Ag complex, which exhibits exceptional hydrophobicity with a water contact angle of 134°, and high chemical stability in water at pH 2-13. The seemingly rigid adsorbent shows a pore-opening or nonporous-to-porous type butane adsorption isotherm and complete exclusion of isobutane, indicating potential molecular sieving.

Two Isostructural Flexible Porous Coordination Polymers Showing Contrasting Single-Component and Mixture Adsorption Properties for Propylene/Propane.

Solvothermal reactions of 3-(3-methylpyridin-4-yl)benzoic acid (Hmpba) with Mn(NO) or Co(NO) yielded isostructural porous coordination polymers, [Mn(mpba)]·guest (MCF-56, ) and [Co(mpba)]·guest (MCF-57, ), respectively. X-ray diffraction revealed that and possess similar one-dimensional ultramicroporous channels, and guest-free [Mn(mpba)] () and [Co(mpba)] () possess significantly and slightly contracted channels, respectively. Single-component CH/CH adsorption isotherms and computational simulations showed the typical nonporous-to-porous structural transformations for , in which CH exhibits a significantly lower threshold pressure, and the typical small-pore-to-large-pore structural transformations for , in which CH exhibits a slightly lower threshold pressure.