BF<sub>3</sub>-Functionalized Silica-Coated Magnetic Nanoparticles as a Novel Heterogeneous Solid Acid for Synthesis of Formazan Derivatives via a Green Protocol
作者:Abdolhamid Bamoniri、Naimeh Moshtael-Arani
DOI:10.1246/bcsj.20140298
日期:2015.5.15
A new type of green heterogeneous solid acid was prepared by the immobilization of BF3·Et2O on the surface of Fe3O4@SiO2 core–shell nanocomposite (Fe3O4@SiO2–BF3) and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDS), and transmission electron microscope (TEM). The activity of this super solid acid was probed through the synthesis of aryl diazonium salts as the starting reactant and then, their diazo coupling with aldehyde phenylhydrazones for formation of formazan derivatives in a solvent-free medium at room temperature. This clean and environmentally benign methodology has advantages such as: no need for corrosive and toxic liquid acids, solvents, or buffer solutions, room temperature reaction, high yields, and short reaction times. In addition, long-term stability of aryl diazonium salts supported on the surface of Fe3O4@SiO2–BF3 magnetic nanoparticles (MNPs) at room temperature was one of the most important results of this procedure.
通过在Fe3O4@SiO2核壳纳米复合材料(Fe3O4@SiO2-BF3)表面固定BF3-Et2O制备了一种新型绿色异质固体酸,并通过傅立叶变换红外光谱(FT-IR)、X射线衍射(XRD)、振动样品磁力计(VSM)、场发射扫描电子显微镜(FE-SEM)、能量色散X射线(EDS)和透射电子显微镜(TEM)对其进行了表征。通过合成芳基重氮盐作为起始反应物,然后在室温无溶剂介质中将其与醛基苯肼重氮偶联以形成甲酰肼衍生物,从而探究了这种超固体酸的活性。这种清洁环保的方法具有以下优点:无需腐蚀性和有毒的液体酸、溶剂或缓冲溶液,室温反应,产率高,反应时间短。此外,Fe3O4@SiO2-BF3 磁性纳米粒子(MNPs)表面支持的芳基重氮盐在室温下的长期稳定性也是该方法最重要的成果之一。