Giant Concentric Metallosupramolecule with Aggregation-Induced Phosphorescent Emission

Fluorescent metallosupramolecules
have received considerable attention
due to their precisely controlled dimensions as well as the tunable
photophysical and photochemical properties. However, phosphorescent
analogues are still rare and limited to small structures with low-temperature
phosphorescence. Herein, we report the self-assembly and photophysical
studies of a giant, discrete metallosupramolecular concentric hexagon
functionalized with six alkynylplatinum­(II) bzimpy moieties. With
a size larger than 10 nm and molecular weight higher than 26 000
Da, the assembled terpyridine-based supramolecule displayed phosphorescent
emission at room temperature. Moreover, the supramolecule exhibited
enhanced aggregation-induced phosphorescent emission compared to the
ligand by tuning the aggregation states through intermolecular interactions
and significant enhancement of emission to CO2 gas.