Solvated and Deformed Hairy Metal-Organic Polyhedron

Despite the fact that numerous studies have been conducted to explore the crystalline structures of various metal-organic polyhedrons (MOPs), the direct probing of solvated and deformed structures of MOPs is still rare but critical to the development of processing protocols and the understanding of their structure-property relationship for gas separation and ion transportation. Here, MOPs from the coordination of isophthalic acids and Cu2+ are covalently functionalized with alkyl chains for studies in solutions and at the air/water interface, respectively. As suggested from small-angle scattering studies, the MOP structures in the solvated state remain intact while the grafted linear alkyl arms exhibit an extended conformation, allowing solvent molecules to penetrate into the cavity of MOPs. Meanwhile, under surface pressure at the water/air interface, the hairy MOP structures, as suggested by in situ neutron reflectivity studies, can be deformed and MOP cores are close together while the grafted chains are squeezed upward and downward toward liquid and air phases, respectively. This discovery provides the first direct evidence for the existence of an ion transportation active conformation of hairy MOPs.