Trigonal Prismatic Cu6L3 Coordination Cage: Encapsulation of Aromatic Molecules and Tuned Photoluminescence.

A trigonal prismatic Cu6L3 coordination cage has been assembled from Cu(I) and semi‐rigid bipyrazolyl ligand. The X‐ray crystallography demonstrates that the cage has a cavity and can encapsulate the toluene as a guest, exhibiting thermochromism phenomenon. Empty cage can be obtained by expulsion of the guest through single crystal to single crystal transformation. After removed the guest, the empty cage shows a blue‐shifted emission (580 nm), in comparison to its parent cage (615 nm). The empty cage could further serve as a host to encapsulate other aromatic molecules (e. g. mesitylene), which shows new emission band. The trigonal prismatic Cu6L3 coordination cage provides a platform to make advanced luminescent materials. [ABSTRACT FROM AUTHOR]