title: [Synthesis and spectral characteristics of novel di-schiff base derivatives incorporting oxadiazole ring].
abstract: 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.
authors.affiliation: Key Laboratory of Organo-Pharmaceutic Chemistry of Jiangxi Province, Gannan Normal College, Ganzhou. wutongshu2008@163.com
authors.forename: Tong-bin
authors.initials: TB
authors.lastname: Chen
authors.forename: Xiong-lu
authors.initials: XL
authors.lastname: Zhang
authors.forename: Xiao-lin
authors.initials: XL
authors.lastname: Fan
authors.forename: Xun
authors.initials: X
authors.lastname: Li
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010069:Oxadiazoles / Q000737:chemistry*; D012545:Schiff Bases / Q000138:chemical synthesis* / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010069:Oxadiazoles; D012545:Schiff Bases