Main content area

Metathesis Strategy for the Immobilization of Copper(II) onto Carboxymethylcellulose/Fe3O4 Nanohybrid Supports: Efficient and Recoverable Magnetic Catalyst for the CuAAC Reaction

Zhang, Zhuan, Song, Ping, Zhou, Junbin, Chen, Yang, Lin, Bijin, Li, Yiqun
Industrial & Engineering Chemistry Research 2016 v.55 no.48 pp. 12301-12308
Fourier transform infrared spectroscopy, X-ray diffraction, air, alkynes, carboxymethylcellulose, catalysts, copper, copper sulfate, differential scanning calorimetry, energy-dispersive X-ray analysis, engineering, ferrous chloride, iron oxides, magnetism, nanohybrids, nanoparticles, organic halogen compounds, oxidation, scanning electron microscopy, sodium azide, sodium hydroxide, thermogravimetry, transmission electron microscopy, triazoles
To overcome the inherent obstacles facing the traditional surface modification of Fe₃O₄ magnetic nanoparticles with appropriate capping agents to anchor the catalytically active complexes, a novel retrievable copper(II) catalyst immobilized on carboxymethylcellulose/Fe₃O₄ nanoparticles (Cuᴵᴵ–CMC–Fe₃O₄) magnetic hybrid materials was successfully prepared through three steps of sequential metathesis and one step of oxidation. First, ferrous carboxymethylcellulose (CMC–Feᴵᴵ) was prepared by ionic exchange of ferrous chloride and sodium carboxymethylcellulose (CMC–Na). Second, the resulting CMC–Feᴵᴵ was treated with NaOH solution to form the corresponding hybrid material Na–CMC–Fe(OH)₂, which proceeded to be exposed to the air to afford the Na–CMC–Fe₃O₄. Finally, the as-prepared Na–CMC–Fe₃O₄ was immersed in copper sulfate solution to self-assembly-fabricate the Cuᴵᴵ–CMC–Fe₃O₄ hybrid catalyst by ionic exchange of Cu(II) with Na–CMC–Fe₃O₄. The morphology and structural feature of the catalyst were characterized by different microscopic and spectroscopic techniques such as FT-IR, ICP-AES, XRD, SEM, EDS, TEM, TGA, and DSC. The ensuring catalyst has been successfully applied in the CuAAC reaction of benzyl halides, sodium azide, and terminal alkynes to the synthesis of 1,2,3-triazoles. Furthermore, the Cuᴵᴵ–CMC–Fe₃O₄ could be easily isolated and recovered by magnetic decantation and reused for five consecutive cycles without much loss in activity.