Trackable Supramolecular Fusion: Cage to Cage Transformation of Tetraphenylethylene‐Based Metalloassemblies

Herein, the trackable supramolecular transformation of a two-component molecular cage to a three-component cage through supramolecular fusion with another two-component molecular square is described. The use of tetraphenylethene (TPE), a chromophore with aggregation-induced emission (AIE) character, as a component for the molecular cages enables facile fluorescence monitoring of the transformation process: while both cages exhibit fluorescence emission via the restriction of intramolecular motion of the TPE motif, the interactions between TPE and 4,4'-bipyridine introduced in the supramolecular fusion process result in partial fluorescence quenching and shifts in the emission maximum. This study provides a simple and efficient approach towards complex supramolecular cages with emergent functions and demonstrates that AIE features could provide unique opportunities for the characterization of complex, dynamic supramolecular transformation processes.