Long Time CO Storage Under Ambient Conditions in Isolated Voids of a Porous Coordination Network Facilitated by the "Magic Door" Mechanism.

A coordination network containing isolated pores without interconnecting channels is prepared from a tetrahedral ligand and copper(I) iodide. Despite the lack of accessibility, CO is selectively adsorbed into these pores at 298 K and then retained for more than one week while exposed to the atmosphere. The CO adsorption energy and diffusion mechanism throughout the network are simulated using Matlantis, which helps to rationalize the experimental results. CO enters the isolated voids through transient channels, termed "magic doors", which can momentarily appear within the structure. Once inside the voids, CO remains locked in limiting its escape. This mechanism is facilitated by the flexibility of organic ligands and the pivot motion of cluster units. In situ powder X-ray diffraction revealed that the crystal structure change is negligible before and after CO capture, unlike gate-opening coordination networks. The uncovered CO sorption and retention ability paves the way for the design of sorbents based on isolated voids.