Molecular Sieving of Propyne/Propylene by a Scalable Nanoporous Crystal with Confined Rotational Shutters
Jingmeng Wan, Hao‐Long Zhou, Kim Hyeon‐Deuk, I‐Ya Chang, Yuhang Huang, Rajamani Krishna, Jingui Duan
Abstract
Abstract Soft porous coordination polymers (PCPs) have the remarkable ability to recognize similar molecules as a result of their structural dynamics. However, their guest‐induced gate‐opening behaviors often lead to issues with selectivity and separation efficiency, as co‐adsorption is nearly unavoidable. Herein, we report a strategy of a confined‐rotational shutter, in which the rotation of pyridyl rings within the confined nanospace of a halogen‐bonded coordination framework ( NTU‐88 ) creates a maximum aperture of 4.4 Å, which is very close to the molecular size of propyne (C 3 H 4 : 4.4 Å), but smaller than that of propylene (C 3 H 6 : 5.4 Å). This has been evidenced by crystallographic analyses and modelling calculations. The NTU‐88o (open phase of activated NTU‐88 ) demonstrates dedicated C 3 H 4 adsorption, and thereby leads to a sieving separation of C 3 H 4 /C 3 H 6 under ambient conditions. The integrated nature of high uptake ratio, considerable capacity, scalable synthesis, and good stability make NTU‐88 a promising candidate for the feasible removal of C 3 H 4 from C 3 H 4 /C 3 H 6 mixtures. In principle, this strategy holds high potential for extension to soft families, making it a powerful tool for optimizing materials that can tackle challenging separations with no co‐adsorption, while retaining the crucial aspect of high capacity.