Catalytic activity of Cu nanoparticles supported on Fe<sub>3</sub>O<sub>4</sub>–polyethylene glycol nanocomposites for the synthesis of substituted imidazoles
作者:Zohre Zarnegar、Javad Safari
DOI:10.1039/c4nj00645c
日期:——
In the present study, we carried out chemical synthesis and characterization for a Fe3O4âpolyethylene glycolâCu nanocomposite (Fe3O4âPEGâCu). Firstly, poly(ethylene glycol) was functionalized using cyanuric chloride (PEG-Cl4). Then PEG-Cl4 was linked with Fe3O4 nanoparticles via formation of covalent bonds (Fe3O4âPEG). The Cu nanoparticles were supported by reducing copper ammonia complexes with hydrazine hydrate on the surface of this nanocomposite. Nanoparticles have been characterized by FT-IR, XRD, SEM, EDAX, TGA-DTA, AAS and VSM techniques. The catalytic activity of the Fe3O4âPEGâCu catalyst was evaluated for the synthesis of highly substituted imidazoles. This new catalyst was found to be a highly active and green catalyst for the synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-substituted imidazoles. The synthesized catalysts displayed magnetic properties, which allowed their fast separation from the reaction medium using a simple magnet.
在本研究中,我们进行了Fe3O4-聚乙烯醇-Cu纳米复合材料(Fe3O4-PEG-Cu)的化学合成和表征。首先,聚乙烯醇通过氰尿酸氯化物(PEG-Cl4)进行了功能化。然后,PEG-Cl4通过形成共价键与Fe3O4纳米粒子连接(Fe3O4-PEG)。铜纳米粒子通过在该纳米复合材料表面用肼水合物还原氨铜络合物来支持。纳米粒子通过FT-IR、XRD、SEM、EDAX、TGA-DTA、AAS和VSM技术进行表征。Fe3O4-PEG-Cu催化剂的催化活性在合成高度取代的咪唑时进行了评估。发现这款新催化剂在合成2,4,5-三取代咪唑和1,2,4,5-取代咪唑方面表现出很高的活性且环保。合成的催化剂显示出磁性特性,这使得它们能够通过简单的磁铁快速从反应介质中分离出来。