Long‐Lived Room‐Temperature Phosphorescence of Coronene in Zeolitic Imidazolate Framework ZIF‐8

Long-lived phosphorescence is demonstrated with an emission lifetime of 22.4 s at room temperature from coronene-d 12 encapsulated in the zeolitic imidazolate framework ZIF-8. The guest emitter coronene-d 12 is well isolated in the rigid framework of ZIF-8, enabling long-lived triplet excitons even at higher than 300 K. It is also demonstrated that thermally activated delayed fluorescence can be achieved at temperatures >300 K.