First-Row-Transition Ion Metals(II)-EDTA Functionalized Magnetic Nanoparticles as Catalysts for Solvent-Free Microwave-Induced Oxidation of Alcohols

authors	Martins, NMR; Martins, LMDRS; Amorim, CO; Amaral, VS; Pombeiro, AJL
nationality	International
journal	CATALYSTS
author keywords	alcohol oxidation; ferrite magnetic nanoparticles; transition metals; magnetic recovery; functionalized nanoparticles; microwave irradiation; solvent-free
keywords	ASSISTED PEROXIDATIVE OXIDATION; AEROBIC OXIDATION; SELECTIVE OXIDATION; FE3O4 NANOPARTICLES; EFFICIENT CATALYST; ORGANIC FRAMEWORKS; NANO-ADSORBENT; REMOVAL; COMPLEXES; MICROSPHERES
abstract	A series of first-row transition-metals combined with ethylenediamine tetraacetic acid (EDTA), as metal-based N,O-chelating ligands, at the surface of ferrite magnetic nanoparticles (MNPs) was prepared by a co-precipitation method. Those EDTA functionalized MNPs with general formula Fe3O4@EDTA-M2+ [M = Mn2+ (1), Fe2+ (2), Co2+ (3), Ni2+ (4), Cu2+ (5) or Zn2+ (6)] were characterized by FTIR (Fourier Transform Infrared) spectroscopy, powder XRD (X-ray Diffraction), SEM (Scanning Electron Microscope), EDS (Energy Dispersive Spectrometer), VSM (Vibrating Sample Magnetometer) and TGA (Thermal Gravity Analysis). The application of the magnetic NPs towards the microwave-assisted oxidation of several alcohol substrates in a solvent-free medium was evaluated. The influence of reaction parameters such as temperature, time, type of oxidant, and presence of organic radicals was investigated. This study demonstrates that these MNPs can act as efficient catalysts for the conversion of alcohols to the corresponding ketones or aldehydes with high selectivity and yields up to 99% after 2 h of reaction at 110 degrees C using t-BuOOH as oxidant. Moreover, they have the advantage of being magnetically recoverable catalysts that can be easily recycled in following runs.
publisher	MDPI AG
issn	2073-4344
year published	2017
volume	7
issue	11
digital object identifier (doi)	10.3390/catal7110335
web of science category	Chemistry, Physical
subject category	Chemistry
unique article identifier	WOS:000416780900024