Design,Synthesis And Properties Study Of Pure Organic Phosphorescent Materials With Highl Efficient And Long Lifetime

In recent years,benefiting from their structural flexible,low cost,good processability and biocompatibility,pure organic phosphorescent materials have been widely used for high-sensitive bio-imaging,optoelectronic devices,sensors and anti-counterfeiting.However,due to the low ISC efficiency and the triplet nonradiative inactivation of pure organic phosphorescent materials,it is difficult to exhibit efficient and long-lived room temperature phosphorescence?RTP?.Combined with the phosphorescence mechanism,we designed and synthesized a series of phenylcarbazole derivatives,which improve the phosphorescence properties through the synergistic effect of hetero atoms and heavy atoms,and realize the efficient and long-life RTP emission excited by visible light.First,we designed and synthesized a series of isomerized bromo-substituted phenylcarbazoles,studied the effect of isomerization on the molecular phosphorescence properties,and controlled the crystal structure through homogeneous polymorphism to achieve a long life?200 ms?RTP,this way of changing the phosphorescence properties through structural isomerization and regulating the crystal packing has a certain significance for studying the structure-activity relationship of phosphorescence.Then we introduced heteroatom groups?-CN or-CONH₂?on the basis of Br substitution and systematically studied their phosphorescence properties.The results show that the disubstituted phenylcarbazole derivatives all exhibit strong fluorescence-phosphorescence dual emission.Under the excitation of visible light?400 nm?,the longest phosphorescence lifetime reaches 224 ms,and the highest phosphorescence quantum yield is 13.1%.Basically,the room temperature phosphorescence emission with high efficiency and long life is basically realized.This method of optimizing the phosphorescence properties at room temperature through the synergistic effect of the heavy atom effect and the heteroatom group is of guiding significance for the design and development of new,efficient,and long-lived organic phosphorescent molecules.