Iridium Complex Organic Phosphorescent Materials Synthesis And Performance

Since the heavy metal complexes used as phosphorescent dye dopants in highly efficient OLEDs by Forrest,the utilization of the triplet energy through phosphorescent materials has received vast attentions recently.Heavy metal complexes,particularly those containing iridium(Ⅲ),can emit from their triplet state through strong spin-orbit coupling which leads to singlet-triplet state mixing.When the host materials are excited, both singlet and triplet generated by electron-hole combination on host materials can be transmitted to iridium complexes,revealing highly efficient phosphorescent emissions and enhances the luminance efficiency.However,the probability of singlet excitons formatting in fluorescent materials is 25%,amount to only one third that of the utility of both singlet and triplet excitons,which make the internal quantum efficiency approach 100%,theoretically.Recently,significant research has been focused on the syntheses of new iridium(Ⅲ) complexes and particularly in light emitting diodes.Both the emission wavelength and the EL efficiency of the device are affected greatly by the electronic properties,stereoconstitution and skeleton construction of their organic ligands.therefor -e,design and synthesis of new organic ligands in iridium(Ⅲ) complexes are significant in the exploration of different light emitting diodes.In this work,a series of phosphoresc ent(2-phenyl)-benzothiazolate Iridium(Ⅲ) acetylacetone complexes are synthesized with benzoyl chloride derivatives,2-aminothiophenol and Iridium trichloride anhydrat -e,on the basis of reference to the research in phosphorescent iridium(Ⅲ) complexes at home and abroad.These complexes are characterized by ~1HNMR,FT-IR and Elemental analysis.Solubility,Thermogravitometric analysis,UV-vis absorption and Photolumine scence of the complex are investigated.Finally,a series of 2-phenylbenzothiazolate/substituted(2-phenyl)benzothiazolate Iridium(Ⅲ) acetylacetonate complexes are synthesized.And the structure confirmations suggest that the structures of the resultant complexes are absolutely consistent with the designed ones.All these resultant complexes are almost insoluble in common inorganic solvents,and soluble in alcohol,acetone and dichloromethane slightly.But these comple xes have a better solubility in tetrahydrofuran,dimethyl sulfoxide and chloroform,thes e common organic solvents,which provides them with the facility in properties charac terization.Thermo-gravitometric analysis(TGA) shows the stability of these Iridium(Ⅲ) complexes in the range of 338～360℃.And they can be sublimed at low pressure which makes them easily for high-vacuum thermal evaporation films.The absorption spectra of all the complexes show intense higher energy transitions ~1π-π~*(from 250nm to 350nm) as well as comparatively lower energy and broad singlet and triplet metal to ligand charge-transfer from 400nm to 530nm.These complexes also give rise to a serials of strong yellow photoluminescenc e with wavelengths ranging from 560nm to 600nm.In conclusion,a series of novel phosphorescent material are synthesized in this article and these Iridium(Ⅲ) complexes to be promising organic phosphorescent material for their excellent performance.