Design,Synthesis and Photo/Electro Luminescence Property Study of Novel Linked Imidazole Lonic Iridium Complexes
|School||Northeast Normal University|
|Keywords||Light-emitting electrochemical cell (LEC) Ionic Iridium complexes|
Also known as the Twenty-First Century is information age. With the rapiddevelopment of information industry, Display as an information carrier is an essentialpart of people’s lives. Conventional displays such as the bulky, heavy, high drivevoltage shortcomings have been unable to meet the demand of people. Therefore, theperformance of study the better and better monitor becomes one of the hot.Currently more advanced display technology is a solid light-emittingelectrochemical cell （LEC）. Solid-state light-emitting electrochemical cell of theselected materials are mostly ionic transition metal complexes, This is due to themetal and the strong interaction between the ligand, making the transition metalcomplexes have triplet characteristics of the metal-ligand charge transfer （MLCT）excited state, That metal complexes of heavy metals in the atomic spin-spin coupling,the singlet and triplet mixed, triplet exciton symmetry are destroyed and decayedfaster, so more higher efficient electricity phosphorescence can be generated. Theintersystem crossing （ISC） efficiency from the singlet to triplet is increased. Amongthe several common heavy metals complexes, Ir（Ⅲ） complexes have the advantagesof short phosphorescence life and luminescence quantum efficiency, making these tobe the focus in the research field.Ionic iridium complexes also have more advantages than the neutral iridiumcomplexes. Such as high quantum efficiencies and easily tunable emissionwavelength. Then the ionic iridium complexes can be better electroluminescentmaterials. First, compared with the neutral iridium complexes, conditions for thesynthesis of the ionic iridium complexes are more moderate; Second, ionic iridiumcomplexes as light-emitting materials can use inert metal, such as gold for theelectrode to be efficient light-emitting devices; Third, these complexes have redoxreversibility and stability, can help to improve the stability of the device; Fourth, sincethese complexes carry charge and couter ions, so it is conducive to carrier injection,transport and reduce device power consumption.The main contents of the paper are as follows:1. Linked imidazole is a bidentate ligand containing two protons and two livelylinked imidazole proton is replaced by the solubility of the derivativesincreases, the coordination ability to synthesize more complex. Wesynthesized four contain associated imidazole ionic iridium complexes,Linked imidazole is a bidentate ligand containing two protons and two livelylinked imidazole proton is replaced by the solubility of the derivativesincreases, the coordination ability to synthesize more complex. Wesynthesized four contain associated imidazole ionic iridium complexes, （1）[Ir（ppy）2（byz）]+（PF6-）,（2）[Ir（ppy）2（dbz）]+（PF6-）,（3）[Ir（poz）2（byz）]+（PF6-）and （4）[Ir（poz）2（dbz）]+（PF6-）, where ppy, poz, byz and dbz are phenylpyridine,2,5-Diphenyl-[1,3,4] oxadiazole,1,1’-Bis-pyridin-3-ylmethyl-1H,1’H-[2,2’]biimidazolyl and1,1’-Dibenzyl-1H,1’H-[2,2’]biimidazolyl. All the complexes are characterized bysingle crystal structure, IR, NMR and other characterization.2. Photophysics and electrochemical properties of these complexes are studied.By the UV-visible absorption spectrum and fluorescence emission spectrum,we discuss the excited state properties of the complexes, and clarify thechemical structure of the ligand, Photophysical and electrochemical propertiesof relationships.3. LEC devices are produced to study the electroluminescent properties. Fromthe start-up voltage, response time, maximum brightnessof the LEC devices,we investigate the molecular structure of the complexes changes in the impacton device performance.