Synthesis And Fluorescence Properties Of Pyrazole Oxadiazole And Pyrazole Benzothiazole Oxadiazole Derivatives

The 1,3,4-oxadiazole has great unparalleled performance in electronic-injection and electronic-transmission. It has been widely researched in organic electrotransporting electroluminescent (EL) materials which are small molecule and polymer. In recent years, synthesis and study of pyrazole derivatives have become more and hotter in heterocyclic chemistry because pyrazole possesses good biological activity. Some people have studied for it in photochromic materials, Some compounds with pyrazole ring are good fluorescent whitening agent. Lots of papers about fluorescence property of benzothiazole derivatives were published, and some papers discussed the theory of fluorescence generated in different polar solvent. Compounds containing vinylbenzene structure can be employed as stable materials with high pure rotated blue property. In order to ensure the luminous efficiency, it is important way to embed structure unit of electronic transmission-type in appropriate site of materials.In this paper, twelve pyrazole oxadiazole compounds that three contained non-benzothiazole group and nine contained benzothiazole group were designed and synthesized. The twelve new pyrazole oxadiazole compounds contain the benzothiazole or benzene group in the 1 position of pyrazole, the aromatic group in the 3 position of pyrazole and the formacyl group in the 4 position of pyrazole. A new method of synthesizing 1,3,4-oxadiazole compound was described. The synthesized 1,3, 4-oxadiazole compound was connected with 4-formylpyrazole through Wittig reaction. Their structures were characterized by IR, MS and H NMR spectra. The fluorescence properties were measured by fluorometry. The results showed that the target compounds had good fluorescence andλem ranged from 410 to 450 nm and fluorescence quantum yields up to 0.69.