Synthesis And Characterization Of Phosphorescent Cyclometalated Complexes

Recently, iridium complex have received considerable attention because of their high emission efficiencies and easy tuning of emission colors by changing chemical structures of ligands.An efficacious solution to this problem is to modify the structrure of ligands or introduce phosphorescent dye into the polymer chain by grafting.In this thesis a series of heteroleptic cyclometalate Ir complexes with acylamide derivants as ancillary ligands (pq)₂Ir(LX) (pq=2-phenylquinoline,LX=acetylaniline, N-phenylbenzamide,N-tert-butylbenzamide,pyridine) have been successfully synthesized. At first, the iridium complexe containing pyridine ligands was synthesized in order to confirm the stabilization of Ir-Cl bond. The synthetic procedures are as follows: (pq)₂Ir(μ-Cl)₂Ir(pq)₂ was refleuxed with pyridine, and obtained the (pq)₂Ir(pyridine)Cl. Then the Ir complexes containing amides ligands were synthesized. The synthetic procedures are as follows:Stirred the dicholoro-phenylquinoline complex and amide derivants in the presence of alkali in 2-ethoxyethanol to give birth to the aimed complexes,these are (pq)₂Ir(acetylaniline), (pq)₂Ir(pyridine),(pq)₂Ir(N-Phenylbenzamide),(pq)₂Ir(N-tert-butylbenzamide).All of the structures of complexes were characterized by HNMR, x-ray single crystal diffusion or element analysis.All the complexes give rise to resemble absorptions at around 260nm, and their solution emissions are all fell into the red light region but differ in the max emission wavelength around 590nm, which prove all the complexes are red phosphorescence complexes. The cyclic voltammetry spectra of these complex show that they are redox reversibility The stability of devices can be expected due to their excellent redox stabilities.