Study On The Synthesis And Properties Of 1,3,4-Oxadiazole Derivatives

1,3,4-oxadiazole(OXD) derivatives are the most widely studied electron transport materials because of their electron deficiency, high photoluminescence quantum yield, and good thermal and chemical stabilities. In this paper, the synthesis of six aryl-oxadiazole small molecule compounds and 18 aryl-oxadiazole dual symmetric small molecule compounds. Their optical properties and electrochemical properties were studied. At the same time, was synthesized with main chain oxadiazole group three polymers. And their optical properties were studied. The main contents of this thesis include the following points:1. The development of organic electroluminescence was reviewed in detail. the development history and the Characteristics of OLED; working principles and structure of electroluminescence device were introduced. and then, a lot of electrode materials, light-emitting materials, hole-transporting materials and electron-transporting materials used in OLED were shown. The application of energy band structure in OLED were studied. At last, we set up our main conception of this thesis and the main work.2. Design and synthesis of aril-oxadiazole of small molecule by 1HNMR, FT-IR, MS. Their UV-visible absorption spectroscopy, fluorescence spectroscopy were studied. Absorption spectra show that: The largest UV-absorption peak of target compounds was 277~304nm, fired strong purple fluorescence.3 Design and synthesis of the six with dual dual-aryl-oxadiazole conjugated double bond of the symmetrical compounds, its structure were characterized by 1HNMR, FT-IR, MS. Studied their UV-visible absorption spectra, fluorescence spectroscopy. And determined their electrochemical properties by cyclic voltammetry method UV-visible absorption spectra show that: the largest absorption peak of the target compounds were in 336~350nm was the absorption peak of the benzene ring. In the absorption peak around 300nm is a benzene ring and C=N double bond conjugated. Fluorescence spectra show that: the target compounds launch a strong blue fluorescence. The maximum excitation wavelength occurs around the 395nm. The maximum emission peak appears in 390~477nm. Electrochemical properties show that: electron affinity is form 2.54 to 2.71 eV. Ion potential is form 5.45 to 5.76 eV, have a good hole-blocking effect, performance quite with the commonly used PBD electron transport material. PBD of EA is 2.82 eV.4. Design and synthesis the six dual dual-aryl-oxadiazole compounds of symmetry of the double bond. Using 1HNMR,FT-IR,MS were characterized by its structure. Studied their UV-visible absorption spectra and fluorescence spectrum. UV-visible absorption spectra show that: The largest absorption peak of the target compound is in the 388nm-409nm.Fluorescence spectra show that: The target compound launch a strong blue fluorescence, the maximum excitation wavelength occurs around the 358nm, in 354nm-407nm appears the maximum emission peak.5. Design and synthesis of the six with dual dual-aryl-linked-oxadiazole symmetric compounds. By HNMR,FT-IR,MS, its were characterized by its structure. Studied it`s UV-visible absorption spectroscopy and fluorescence spectroscopy. UV-visible absorption spectra show that: The target compounds appear the largest absorption peak in the 273~304nm. Fluorescence spectra show that: The target compounds launch a strong purple wavelength occurs around 339nm. In the 365nm~430nm, the maximum emission peak appears.Design and synthesis the three aryl-oxadiazole polymers. Using 1HNMR,FT-IR,MS, its structure were characterized. Studied their UV-visible absorption spectroscopy. Fluorescence spectra show that: The target compound 5a appears the largest absorption peak in the 324nm. The largest absorption peak of 5b and 5c appear in the 240nm and 244nm. Fluorescence spectra show that: The target compounds launch a strong blue fluorescence. The maximum excitation wavelength occurs around 364nm. The largest absorption peak of 5b appears in the 376nm. And the largest absorption peak of 5a and 5c respectively appears in the 405nm and 417nm.