Phosphine‐Manipulated <i>p</i>‐π and π<i>‐</i>π Synergy Enables Efficient Ultralong Organic Room‐Temperature Phosphorescence
Xiaoqing Song, Guang Lu, Yi Man, Jing Zhang, Shuo Chen, Chunmiao Han, Hui Xu
Abstract
Abstract Organic room temperature phosphorescence (RTP) attracts extensive attentions, but still faces the challenge of achieving both high RTP efficiencies ( η RTP ) and long lifetimes ( τ RTP ), due to the intrinsic contradiction between triplet radiation and stabilization. In this work, we developed three carbazole‐triphenylphosphine hybrids named x CzTPP, in which phosphine groups provide nonbonding electrons and steric hindrance to modulate intermolecular p ‐π and π‐π interactions. With the rational orientations and spatial positions of functional groups, para ‐substituted p CzTPP achieves high η RTP over 10 % and more than twofold increased τ RTP (>600 ms), compared to ortho ‐ and meta ‐ isomers. Theoretical simulation and photophysical investigation indicate that the strongest intermolecular p ‐π and π‐π electronic interplays of p CzTPP harmonize high transition probability of 3 p π state and triplet stability of 3 ππ state, reflecting the p ‐π and π‐π synergy in RTP process.