High Pressure In Situ Single‐Crystal X‐Ray Diffraction Reveals Turnstile Linker Rotation Upon Room‐Temperature Stepped Uptake of Alkanes

Abstract The rare availability of suitable single‐crystal X‐ray diffraction (SCXRD) structural data allows for the direct interpretation of the response of a framework to gas sorption and may lead to the development of improved functional porous materials. We report an in situ SCXRD structural investigation of a flexible MOF subjected to methane, ethane, propane, and butane gas pressures. Supporting theoretical investigations indicate weak host–guest interactions for the crystallographically modelled gaseous guests and, in addition, reveal that a turnstile mechanism facilitates the transport of alkanes through the seemingly nonporous system. Inflections present in the adsorption isotherms are furthermore rationalized as due to gate‐opening, but without the expected creation of new accessible space.