Abstract
Herein, we present a flexible MOF (PCN-41) composed of a thioether-based linker and a stair-like {Cu4I4} cluster. Upon the inclusion of liquid organic molecules, PCN-41 undergoes a single crystal to single crystal transformation to allow for ordered arrangement of the guest molecules. By virtue of the low symmetry, structural flexibility, and the electron-rich cavity environment, PCN-41 exhibits crystalline sponge behavior toward a series of electron-deficient liquid molecules including DMF, MeCN, NMP, DMSO and benzaldehyde.