新型含噁二唑环双元席夫碱的合成与光谱特性

4-硝基苯甲酸与硫酸联氨在H₃PO₄/P₂O₅作用下脱水环化生成2, 5-二(4-硝基苯基)-1,3, 4-噁二唑(1)，(1)被Zn/CaCl₂还原为2, 5-二(4-氨基苯基)1,3, 4-噁二唑(2)，(2)与芳香醛反应合成8个含噁二唑环的新型双元席夫碱，产率为65%～81%，用1H NMR，FTIR，MS对其结构进行了验证。研究了它们的UV-Vis光谱和荧光光谱，并用循环伏安法测定了其电化学性能。UV-Vis光谱表明：标题化合物没出现噁二唑环和席夫碱单元所对应的特征吸收峰，共轭效应使两个结构的能带发生了部分杂化而形成新的能带结构，在345～357 nm出现最大吸收峰。荧光光谱表明：目标化合物发射强的紫蓝色荧光，在390～407 nm出现最大发射峰。电化学性能表明：电子亲合势为2.36～3.04 eV，离子势为5.35～6.06 eV，除了3a，3h外，它们的电子传输性比常用的电子传输材料PBD(E_A=2.82 eV)优越。此研究为进一步研究其在有机电致发光器件中的应用提供了参考。

Synthesis and Spectral Characteristics of Novel Di-Schiff Base Derivatives Incorporting Oxadiazole Ring

4-nitrobenzoic acid and hydraxine sulfate were cyclized with H₃PO₄/P₂O₅ to afford 2,5-bis(4-nitrophenyl)-1,3,4-oxadiazole(1), then(1)was reduced to 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole using Zn/CaCl₂ as reduction reagent, and at last, a series of novel di-schiff base derivatives containing oxadiazole ring were obtained by the reaction of 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole with aromatic aldehydes (yield：65%-81%). The structures of these compounds were confirmed by 1H NMR, FTIR and MS. Their UV-Vis spectra as well as fluorescence spectra were studied and the electrochemical properties were tested with cyclic voltammetry. The UV-Vis spectroscopy results show that the characteristic absorption peaks of 1,3, 4-oxadiazole unit and di-schiff base unit disappeared. The maximum absorption wavelength was detected at 345-357 nm because conjugation effect made the two energy bands partially hybrid and form a new energy band structure. Fluorescence spectroscopy results show that they emit strong blue and purple fluorescence, and the emission maximum wavelengths of di-schiff base are from 390 to 407 nm. Electrochemical properties results show that they have higher affinity energy (2.36-3.04 eV) and ionic potential (5.35-6.06 eV), which indicated that they have better electron-transporting properties than PBD except 3 a and 3 h. The results give a reference to further application to organic electroluminescent devices of the target compound.