Two GiantCalixarene‐LikePolyoxoniobate Nanocups {Cu₁₂Nb₁₂₀} and {Cd₁₆Nb₁₂₈} Built from Mixed Macrocyclic Cluster Motifs

Abstract

Cup-shaped molecules are of great interest due to their appealing architectures and properties. Compared with widely studied calixarenes, polyoxometalate-based cupshaped molecules currently remain a virgin land waiting for exploration. In this work, we report the first discovery of two giant cup-shaped inorganic-organic hybrid polyoxoniobates (PONbs) of {Cu 12 Nb 120 } and {Cd 16 Nb 128 }. The former integrates three tricyclic Nb 24 clusters and a hexacyclic Nb 48 cluster into a cup-shaped molecule via a Cu 12 metallacalixarene, while the latter unifies two tricyclic Nb 24 clusters and a brandnew pentacyclic Nb 40 cluster into another cup-shaped molecule via a hybrid Cd 16 unit. With 132 and 144 metal centers, {Cu 12 Nb 120 } and {Cd 16 Nb 128 } show the largest two inorganicorganic hybrid PONbs known to date.