Synthesis And Application Of Benzoxazole Photoelectric Materials And Optimization For Synthesis Of Intermediates

OLED(organic light-emitting diode)is a self luminous display under current passing condition,mainly composed of organic layer,cathode and anode.OLED is widely used in TV,smart phones,smart wearable,VR,automotive display,automotive lighting and other fields,with the advantages of traditional LED lighting.However,in the process of production and use of OLED devices,the problem of poor performance of devices still exists.The main factors affecting the device performance are the thermal stability,electrochemical performance and optical performance of organic molecules.In this thesis,two kinds of organic electroluminescent materials(BBS and BBF)were synthesized and characterized.The energy levels,thermal stability,electrochemical properties and optical properties of the organic electroluminescent materials were studied.The synthesis of important OLED intermediates was optimized.The main contents are as follows:1.The novel organic compound(BBF)was synthesized by 7 steps,using 2-brombiphenyl as starting reactant.The synthesis of BBF involved Suzuki reaction,bromination of aromatics,reduction of nitro into amino group,and syncyclization of aromatic amines.The synthesis is based on the most elementary small organic molecules to produce achieves economic production.The compound BBS was synthesized by 2 steps involved cyclization reaction and Suzuki reaction.In the synthesis of BBS,grinding was used to avoid the pollution of the solvent and the loss of raw materials with 89% yield.Economic,environmental and efficient organic synthesis was realized.Then,through the Gaussian 09 software,the highest occupancy orbit(HOMO)and the lowest space orbit(LUMO)energy level of BBS and BBF were calculated by density functional theory(DFT)at the levels of b31yp/6-31g(d).The energy levels of BBS are 4.72 e V and 2.06 e V respectively.The energy levels of BBF are 4.92 e V and 1.87 e V respectively.The electrochemical properties of BBS and BBF were studied by cyclic voltammetry.The thermodynamic properties of BBS and BBF were studied by thermogravimetric analysis(TGA).The thermal decomposition temperature(Td)of BBS was 427 ?,and the thermal decomposition temperature(Td)of BBF was 493?.The intensity of fluorescence emission and UV-Vis absorption of BBS and BBF were studied by spectroscopic analysis.2.The preparation and detection of devices: the detection results of phosphorescent devices BBS-1 and BBS-2 show that:(1)the hole injection layer HAT-CN plays a positive effect in the device structure,which can effectively reduce the starting voltage and increase the luminance of the device;(2)The performance of phosphor device BBF-1 is better than that of phosphorescent device BBS-1.Therefore,the material BBF is stabler than BBS material and is more suitable for luminescent layer materials.The detection results of the OLED device BBF-3 show that BBF can be successfully used as the luminescent layer material and makd the non-doped fluorescent OLED devices with reliable and stable properties.The detection results of the fluorescent device BBF-2 show that the new material BBF is doped with the fluorescent agent YLE,the performance of the device is greatly improved.3.The optimization of the synthesis of 1,8-dibrom naphthalene,4,7-dibrom-5,6-difluoro benzothiazolidine and 2-(3-bromophenyl)-1,3-diazotriphenylene which are important intermediates for synthesis of organic electroluminescent materials with the yields of 49%,73% and 81% respectively.