Synthesis, Their Properties Of Heavy Metal Complexes And Pyrazine, Quinoxaline Derivatives

With the science and technology developing quickly, peoples life is improving continuousil. The light, illuminating the world, brings people luminosity and hope for living and working. The flat-panel-display devices have been improving by the generation and generation. With the OLED device successfully made, the properties of flat-panel-display have enhanced more and more. Recently scientists have beening reserached the phosphorescence materials, mostly heterocyclic organic compounds with heavy metal. Because the electrons of heterocyclic and empty orbits of metal combine, the metal complexes have a strong spin-orbit coupling, and the origanal prohibited triplet state transitions into permitting. Double singlet and triplet excitons are used for phosphorescence, consequently the luminous efficiency of OLED apparatus can be improved greatly. In theory, the internal quantum efficiencies can reach 100 %. Therefore the metal complexes applying OLED apparatus have great potential.Heterocyclic organic matters, which have two nitrogen atoms, were mostly reported in this paper, and synthesized a series of pyrazine and quinoxaline compounds. The ancillary ligands are actylacetone(acac), N,N'-diethyldithio carbamate(Et2dtc), O,O'-diethyldithiophosphate(Et2dtp), and the heavy metals are iridium and platinum. Good results were obtained by experimentation. This paper involves three parts:(Ⅰ) A series of pyrazine and quinoxaline were designed and synthesized, including 2,3-diphenyl-pyrazine(DPP), 5-methyl-2,3-diphenyl-pyrazine(MDPP), dibenzo[f,h]quinoxaline (DBQ), 2-methyl-dibenzo[f,h]quinoxaline (MDQ) and their iridium complexes. All the compounds were detected by melting point , IR, NMR, MS, element analysis. At the same time the photophysical characterization and electrochemistry of these complexes have been investigated. The experiment results show that the complexes with actylacetone used for ancillary ligands have high yield and good purity. Different substituent groups and different conjugate degrees influence the luminous efficiency for phosphorescence materials. These iridium complexes are preferable luminescent materials.(Ⅱ) 5-methyl-2,3-diphenyl-pyrazine(MDPP) and MDQ as initiative material, bromized with NBS, then substituented by carbazole. The complexes with carbazole, which have function of transmitting cavity, were synthesized. These iridium complexes were detected by melting point , IR, NMR, MS, element analysis. Also the photophysical characterization and electrochemistry of these complexes have been investigated. Relative to the first heterocycle compounds, the iridium complexes with carbazole have some difficulty for purity and yield. The experiment results show that the maximal emission wavelength of these iridium complexes red shift, which have high-efficiency for phosphorescence materials.(Ⅲ) Four platinum complexes were designed and synthesized. The heterocycle organic compounds are 9-(5,6-Diphenyl-pyrazin-2-ylmethyl)-9H-carbazole (CzMDPP). 5-methyl-2,3-diphenyl-pyrazine(MDPP), 2,3-diphenyl-quinoxaline(DPQ), 2-methyl-dibenzo[f,h]quinoxaline (MDQ), All the platinum complexes were detected by IR, NMR, MS, element analysis. And the photophysical characterization have been researched. Compared to iridium complexes, the maximal emission wavelength of platinum complexes blue shift, and their luminescence efficiency becone lower.