Abnormal Compressive Behaviors of Metal-Organic Frameworks under Hydrostatic Pressure

Intuition indicates that materials will contract in all crystal directions under hydrostatic pressure, i.e., all of their axes exhibit positive linear compressibility (PLC) when uniformly compressed. However, some exceptions have been found to exhibit negative linear compressibility (NLC), negative area compressibility (NAC), zero linear compressibility (ZLC), or zero area compressibility (ZAC); these materials are thought to have promising applications under high-pressure conditions, such as would be needed for highly sensitive pressure detectors and deep-sea optical devices. In this Perspective, we summarize the four kinds of abnormal compressive behaviors of MOFs under hydrostatic pressure, including the mechanisms and effects of guest, PTM, and metal atomic radius, which we hope to be helpful to develop practical future application of abnormal compressive materials.