Ultralong room-temperature phosphorescence of a solid-state supramolecule between phenylmethylpyridinium and cucurbituril†
Long-lived organic room-temperature phosphorescence (RTP) has received great attention because of its various potential applications. Herein, we report a persistent RTP of a solid-state supramolecule between a cucurbituril (CB) host and a heavy-atom-free phenylmethylpyridinium guest. Significantly, the long-lived phosphorescence completely depends on the host–guest complexation, revealing that the non-phosphorescent guest exhibits a 2.62 s ultralong lifetime after being complexed by CB under ambient conditions. The ultralong RTP is because of tight encapsulation of CB, which boosts intersystem crossing, suppresses nonradiative relaxation and possibly shields quenchers. Moreover, several phosphorescent complexes possessing different lifetimes are prepared and successfully applied in triple lifetime-encoding for data encryption and anti-counterfeiting. This strategy provides a new insight for realizing purely organic RTP with ultralong lifetime and expands its application in the field of information protection.