Construction and Application of Large Stokes-Shift Organic Room Temperature Phosphorescence Materials by Intermolecular Charge Transfer

Notably, the intermolecular charge transfer between pyrene(Py)and benzophonenes (BPs) can significantly enhance the quantum yieldof the triplet state of Py, which will convert Py from a fluorescencemolecule to a phosphorescence molecule. The intermolecular chargetransfer is confirmed by steady-state and time-resolved spectroscopyand theoretical study. Based on these foundations, Py is doped intoBPs systems and a large Stokes-shift organic room temperature phosphorescence(ORTP) is observed. By using different benzophenone derivatives, aseries of host-guest ORTP materials with different luminescentproperties adjusted by intermolecular charge transfer features aredeveloped. Fortunately, these host-guest ORTP systems frombenzophenone derivatives and pyrene are readily fabricated, and thered gradient color lasting as long as 3 s is observed after removingUV excitation. This host-guest charge transfer strategy playsan important role in the mechanism of the luminous type shift. Ourstrategy paves the way to design ORTP materials conveniently and applythese materials in encryption and temperature alarm device.