Abstract
Encapsulation behavior, as well as the presence of Âé¶¹Ó°Òô catalytically active sites, has been spurring the applications of a 3 nm hollow spherical metal oxide cluster {Mo132} as an encapsulation host and a nanoreactor. Due to its well-defined and tunable cluster structures, and nanoscaled Âé¶¹Ó°Òô void space comparable to the volumes of small molecules, this cluster provides a good model to study the dynamics of materials under nanoconfinement. Neutron scattering studies suggest that bulky Âé¶¹Ó°Òô ligands inside the cluster show slower and limited dynamics compared to their counterparts in the bulk state, revealing the rigid nature of the skeleton of the Âé¶¹Ó°Òô ligands. NMR studies indicate that the rigid Âé¶¹Ó°Òô ligands that partially cover the interfacial pore on the molybdenum oxide shells are able to block some large guest molecules from going inside the capsule cluster, which provides a convincing protocol for size-selective encapsulation and separation.