Design, preparation and characterization of Fe 3 O 4 @SiO 2 @ECH@Thiocarbazide@Au(III)@Chitosan nanoparticles as a catalyst for the synthesis of 3, 4-dihydropyrano [3,2 -c]chromenes

Abstract

Abstract A magnetic nanostructured iron/silica/ linker/ gold ions/ chitosan, has been synthesized to achieve an efficient and reusable catalyst characterized by X-ray diffraction, scanning, and transmission electron microscopies, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and inductively coupled plasma optical emission spectrometry. To improve their stability and increase surface the achieved multilayer nanocomposite has been capsulated in chitosan and glutaraldehyde network. It was found that the obtained nanoparticles have diameter size from 43 to 72 nm. The optimized nanocatalyst applied an efficient and easy friendly procedure for the synthesis of 3, 4-dihydropyrano [3,2-c]chromenes from aromatic aldehyde or aromatic glyoxal, malononitrile, and cyclohaxane-1,3-dione in water at room temperature. The prepared nanocatalyst will be quickly recovered employing an external magnet and reused several times without significant activity loss.