Au nanoparticles decorated on EDTA functionalized Poly (NIPAM- co -allylamine) grafted Fe 3 O 4 for reduction of nitroarenes

A novel smart catalyst of Au nanoparticles supported on EDTA (ethylenediaminetetraacetic acid) functionalized temperature-sensitive copolymer consists of N -isopropyl acrylamide (NIPAM) and allylamine onto silica-modified Fe 3 O 4 MNP (Fe 3 O 4 @Si@P(NIPAM- co -allylamine)-EDTA@Au) was prepared. Initially, Fe 3 O 4 was synthesized and modified with silica particles, and then P(NIPAM- co -allylamine) was grafted onto it via conventional free radical polymerization. Afterwards, polymer grafted MNPs were functionalized with EDTA and decorated with Au NPs to produce an organized heterogenous catalytic structure. Easy separation and recycling, high dispersion of catalytic sites, as well as good thermal stability, and superior efficiency in water as a green solvent are among the great advantages of this system. The novel heterogeneous catalyst showed remarkable catalytic activity for the reduction of numerous aryl-nitro derivatives containing electron-poor, electron-rich, and ortho-substituted. This catalytic system performed excellently for at least 8 repeated cycles without significant degradation in catalytic activity, structure change, and leaching. Furthermore, the temperature responsiveness feature of the catalyst causes the catalyst's switchable on/off behavior.