Synthesis, Characterization And Properties Of Ir(Ⅲ) Complexes And Novel Five-membered Heterocycles Containing Zole Units

The flat-panel-display device will have great improved, as OLEDs are successfullymade. Phosphorescent heavy metal complexes competing with fluorescent material mayhave potential of highly quantum efficiencies. Because both singlet and triplet statesexcitions are contributed to phosphorescence, the internal quantum efficiencies canreach 100 % in theory. As the result, a more efficiency Iridium complexes become moreand more popular in the OLEDs field.One of the best emitting heteroleptic iridium complexes with 1,3,4- oxadiazolederivatives as cyclometalated ligands, and actylacetone (acac) or dithiolates, such asO,O'-diethyldithiophosphate (Et₂dtp) or N,N'-diethyldithio carbamate (Et₂dtc), asancillary ligands, have been synthesized. In order to gain better emitting iridiumcomplexes, five iridium complexes have successfully been synthesized by chemicallymodifying the cyclometalated ligands.There are three parts to be included in this paper:I) On the chapter (I), two series compounds which separatetly substitute by fluorinand carbazole have been systematically designed, synthesized. The five-memberedheterocycles contains thiadiazole, oxadiazole, triazole unites separately. Thesecompounds are successfully synthesized and proved by NMR, IR and MS. The crystalstructures of compounds (cth and cox) have been determined by x-ray diffractionanalysis. The electrochemistry and photophysical characterization of this complex havebeen investigated. This provides some clue to design and develop new phosphorescentmaterials. The second series compounds are of subsituting fluorin of first compounds bycarbazole. As the carbazole and oxadiazole with function of transmitting cavity andelectron, the second compounds including two groups have greatly improvedefficiency.These compounds are required which can make the fabrication smplified andimprove emitting efficency largely.II) On the chapter (II), we report a systematic design, synthesis, characterizationand Crystal Structure of yellow-emitting Ir (III) complexes, (fth)₂Ir(acac) (acac=actylacetone), (fth)₂Ir(Et₂dtp) (Et₂Bdtp=O,O'-diethyldithiophosphate), (fth)₂Ir(Et₂dtc)(Et₂dtc = N,N'-diethyldithiocarbamate). Fth (2, 5-bis (4-fluorophenyl)-1, 3, 4- thiadiazole),which contain F groups in the pyridyl of the ligand, can result in markedlyreduced concentration quenching of luminescence and excellent volatility that aidsdevice processing. What is more, the three ancillary ligands are expected to contributeto modulate wavelength luminescence of its iridium complexes. III) On the chapter (III), two of Ir (III) complexes with the second series compounds (cox and cth) and ancillary Ligand (acac) have successfully been synthesized and fully characterized by NMR, IR. The electrochemistry and photophysical characterization of this complex have been investigated. These Ir (III) complexes show much higher efficiency.