نتایج جستجو برای: magnetic catalyst

تعداد نتایج: 381387  

Javad Safari Zohre Zarnegar

To be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. Fe3O4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature under ultrasound irra...

Hosein Hamadi, Maryam Gholami Mehdi Khoobi

A novel magnetically immobilized polyethyleneimine (PEI) fabricated by covalently anchoring on silica coated Fe3O4 nanoparticles (PEI@Si-MNPs) was prepared. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The immobili...

Javad Safari Zohre Zarnegar

To be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. Fe3O4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature under ultrasound irra...

2014
David Greene Raquel Serrano-Garcia Joseph Govan Yurii K. Gun’ko

In this work, CoFe₂O₄@SiO₂@TiO₂ core-shell magnetic nanostructures have been prepared by coating of cobalt ferrite nanoparticles with the double SiO₂/TiO₂ layer using metallorganic precursors. The Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Analysis (EDX), Vibrational Sample Magnetometer (VSM) measurements and Raman spectroscopy results confirm the presence both of the silic...

Journal: :Chemical communications 2015
Yangzhi Zhu Xiangcun Li Gaohong He Xinhong Qi

Magnetic C-C@Fe3O4 hollow microspheres were prepared by using aerosol-based Fe3O4@C-SiO2 core-shell particles as templates. The magnetic double-shelled microspheres efficiently worked as carriers to load Pt nanoparticles, thus making the catalyst recyclable and reusable.

Journal: :organic chemistry research 0
meghdad karimi tarbiat modares university-tehran_iran athar nakisa tarbiat modares university-tehran_iran kobra azizi tarbiat modares university-tehran, iran akbar heydari tarbiat modares university-tehran_iran

we have used tungestophosphoric acid to catalyze oxidative amidation reaction from benzyl alcohols and methylarens with hydrochloride salts of amines. to achieve this purpose, modified magnetic nanoparticles (γ-fe2o3@sio2@h3pw12o40) were applied as catalyst and tbhp as external oxidant. after optimizing, different derivates of benzamides were synthesized in good yields. also, the result of two ...

اعظمی گیلان, رؤیا , شکوهی, رضا , ملا محمودی, محمد ,

Background and purpose: Bisphenol A is an estrogenic substance that can cause endocrine dysfunction, which extensively enters water resources due to its large use in industry. The aim of this study was to synthesis modified magnetic nanoparticles with sodium alginate and study of its efficiency for removal of Bisphenol A from aqueous solutions using heterogeneous fenton process. Materials an...

Journal: :Chemical communications 2012
Rafael Cano Miguel Yus Diego J Ramón

A new impregnated iridium on magnetite catalyst has been prepared, characterized, used and recycled, up to ten times with practically the same activity, for the first practical cross-alkylation of primary alcohols. The catalyst showed a wide reaction scope, is easy to prepare and handle, and it could be removed from the reaction medium just by magnetic sequestering.

Journal: Journal of Nanoanalysis 2018

In this work, various 3-cyano-4-aryl-4H-pyran derivatives were prepared efficiently through a one-pot,multicomponent synthesis between aromatic aldehyde, malononitrile and acetophenone derivativesor ethyl acetoacetate using Fe3O4/EDTA magnetic nanocatalyst and ethanol as solvent. The reactionswere completed at room temperature in 10 min using 5 mg of catalyst and 2 mL of solvent to prepare1 mmo...

Journal: :Organic & biomolecular chemistry 2015
Ali Khalafi-Nezhad Maryam Nourisefat Farhad Panahi

In this study, L-cysteine was chemically grafted to magnetic nanoparticles in order to prepare a reusable magnetic material incorporating an amino acid moiety. For this purpose, silica-coated magnetic nanoparticles (Fe3O4@SiO2) were reacted with trimethoxy(vinyl)silane to produce vinyl-functionalized magnetic nanoparticles (VMNP). Reaction of a VMNP substrate with L-cysteine in the presence of ...

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