Synthesis Of Cyclometalated Platinum Complexes And Their Application In White OLED

Among the phosphorescent materials with heavy atoms,the Pt complex has good planarity,which leads to obvious intermolecular interactions and affects its luminescence performance.Studies have shown that the introduction of large bulky substituents can effectively solve this problem.Among various substituents,the spiro ring is an ideal substituent,and its rigidity is good,which is conducive to the light emission.However,the synthesis of Pt complexes with spirocyclic rings is relatively complicated,especially the synthesis of spirocyclic intermediates,which generally requires multi-step reactions and has complex synthesis operations.Based on this problem,our main work is as follows:1)We explored a one-pot method to prepare spiro ring intermediate M1,the reaction yield reached74.6%;2)we explored a more reasonable synthesis of spiro ring Pt The synthetic route of the complex,especially the discovery of the intermediate M3 that has two reaction sites-Cl and-Bpin.By adjusting the reaction conditions,we introduced different groups at different sites to obtain different Pt complexes with spiro ligands.3)We have performed theoretical calculations and spectral tests on the Pt complex synthesized by this route,and found that the frontal orbital is less distributed on the spiro ring,and the main effect of the spiro ring is only to increase the distortion of the molecule;4)We combined one of them Pt4 is used as a guest material and a TADF sky blue molecule(DMAC-DPS)is used as a host material as a light-emitting layer.By adjusting the doping ratio of Pt4(1%,2%,3%),different mixed white light can be obtained.The device has a maximum external quantum efficiency(EQE)of 5%and a maximum brightness of 1776 cd/m~2.