Monitoring the effect of metal compositions on the short- and long-range dynamic structural response of a flexible heterobimetallic MOF for

Structural dynamic in metal-organic frameworks (MOFs) has a dramatic impact on their CO2 adsorption properties. An understudied approach to induce this dynamic behavior is represented by the modulation of the metal composition of the metallic nodes. We recently discovered that the structural flexibility of a known MOF strictly depends on its metal composition, affecting and improving its CO2 uptake performances. We indeed propose to perform a combined in situ XAS/HR-PXRD+PDF experiment to deeply elucidate the short- and long-range structural rearrangement mechanisms and the host-guest interactions of such systems during CO2 adsorption. The results will highlight the direct influence of the nature and relative composition of the metal nodes on the structural dynamics of the framework and on its adsorption capability. We believe that the instrumental setup of BM31 is extremely suitable for performing such a study, and the results will be unprecedented in the field of CO2 adsorbents.