Soft corrugated channel with synergistic exclusive discrimination gating for CO(2) recognition in gas mixture

Developing artificial porous systems with high molecular recognition performance is critical but very challenging to achieve selective uptake of a particular component from a mixture of many similar species, regardless of the size and affinity of these competing species. A porous platform that integrates multiple recognition mechanisms working cooperatively for highly efficient guest identification is desired. Here, we designed a flexible porous coordination polymer (PCP) and realised a corrugated channel system that cooperatively responds to only target gas molecules by taking advantage of its stereochemical shape, location of binding sites, and structural softness. The binding sites and structural deformation act synergistically, exhibiting exclusive discrimination gating (EDG) effect for selective gate-opening adsorption of CO(2) over nine similar gas molecules, including N(2), CH(4), CO, O(2), H(2), Ar, C(2)H(6), and even higher-affinity gases such as C(2)H(2) and C(2)H(4). Combining in-situ crystallographic experiments with theoretical studies, it is clear that this unparalleled ability to decipher the CO(2) molecule is achieved through the coordination of framework dynamics, guest diffusion, and interaction energetics. Furthermore, the gas co-adsorption and breakthrough separation performance render the obtained PCP an efficient adsorbent for CO(2) capture from various gas mixtures.