Synthesis And Properties Of Phosphorescent Materials Based On Iridium And Platinum Complexes

Transition metal complex phosphorescent materials have higher luminous efficiency than conventional fluorescent materials.In electroluminescence,the excitons generated by the recombination have singlet and triplet states,of which25%are singlet excitons,and 75%are triplet excitons,so their number ratio is 1:3.Therefore,the maximum internal quantum efficiency of the fluorescent material is25%;the quantum efficiency in the phosphorescent material is up to 100%.The iridium complex phosphorescent material has the advantages of high luminous efficiency and adjustable luminescent color,and is relatively mature in the development of phosphorescent materials.Platinum complexes also have strong spin-orbit coupling,and their emission wavelengths can cover the entire range of blue to red light,so they have begun to attract people's attention.In this paper,we synthesized eight new iridium complex phosphorescent materials and two new platinum complex phosphorescent materials,and determined their structures by NMR and MS,and their photophysical properties,electrochemical properties,and photoluminescence properties were tested.The main content of this paper:1.Three ligands were synthesized:a 3-methyl-6-phenylimidazo[2,1-b]thiazole?mpmt?ligand was synthesized,and then a trifluoromethyl group was introduced on the benzene ring of the ligand.Modification to give the derivative3-methyl-6-?4-?trifluoromethyl?phenyl?imidazo[2,1-b]thiazole?mtfpmt?ligand,in additionto1,10-phenanthroline?phen?synthesizing2-?1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl?phenol?L1?ligand;2.Using mpmt and mtfpmt as main ligands,L1,2,2-bipyridine?bpy?,1,10-phenanthroline?phen?are used as an auxiliary ligand,and six kinds of iridium complex phosphorescent materials are synthesized with metal IrCl₃·3H₂O;3.Using 2-?2-pyridyl?benzothiophene?btp?as the main ligand and binding L1,a novel iridium complex[?btp?Ir?L1?]Cl was prepared,followed by the synthesis of[?btp?Ir?L1?]Cl treated with boron trifluoride diethyl ether to synthesize a new iridium complex;4.Using btp as the main ligand,combined with L1,mpmt,and two kinds of platinum complex phosphorescent materials were synthesized with metal K₂PtCl₄;A series of characterization tests were performed on all complexes.[?mtfpmt?₂Ir?L1?]Cl and[?mtfpmt?₂Ir?phen?]Cl have increased the color purity and photon yield before introducing a trifluoromethyl group,among them,[?mtfpmt?₂Ir?phen?]Cl has a color purity of more than 80%and can be used as a good blue phosphorescent material.[?mtfpmt?₂Ir?bpy?]Cl after the introduction of the trifluoromethyl group,the expected red shift occurred at the maximum emission wavelength.[?btp?₂Ir?L2?]Cl increases the conjugate degree and red shift after the boron trifluoride is introduced into the ancillary ligand,and its color purity and photon yield are higher,which can be used as a good red phosphorescence material.We successfully cultured and parse a single crystal of?btp?Pt?mpmt?Cl.The results of various properties indicate that the luminescent properties of these complexes can be affected whether the main ligand is changed or the ancillary ligand is changed.In general,the introduction of trifluoromethyl and fluorine can red shift the maximum emission wavelength of the complex by reducing the LUMO orbital of the complex.However,the ancillary ligand also affects the luminescence of the complex.After the introduction of the trifluoromethyl group,the energy level gap of the complex may be increased,and the maximum emission wavelength of the complex is blue shifted.