Guest effects on crystal structure and phosphorescence of a Cu6L3 prismatic cage†
Coordination cages with a nanocavity can encapsulate various guests, which allows modulation of the physical and chemical properties of the host–guest inclusion complexes. In this work, we designed and prepared a phosphorescence Cu6L3 trigonal prismatic cage, which accommodates a series of aromatic guest molecules. Single crystal X-ray analysis revealed that the intermolecular Cu⋯Cu distance can be mediated by changing the volume of the guests. Moreover, the host–guest charge-transfer interactions can be also fine-tuned via tailoring the ionization potential of guests. Consequently, we have observed the guest-induced photoluminescence properties change including a gradual red shift of the maximum emission peak and a linear relationship between the quantum yield and ionization potential of guests.