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.