Magnetically Reusable MnFe₂O₄ Nanoparticles Modified with Oxo‐Peroxo Mo (VI) Schiff‐Base Complexes: A High Efficiency Catalyst for Olefin Epoxidation under Solvent‐Free Conditions

Abstract

In this research work, we report on the preparation of a new catalyst based on MnFe2O4 nanoparticles modified with an oxo‐peroxo molybdenum (VI) Schiff base complex. The catalyst was characterized by various techniques, including Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS). The epoxidation catalytic activity of the developed catalyst was tested on various alkenes by t‐butyl hydroperoxide (TBHP) as oxidant under solvent‐free condition. The catalyst showed excellent conversion (>99%), selectivity (100%), turn over frequency (9504 h−1), and a short reaction time (5 min). Moreover, the catalyst is recoverable up to five cycles with no significant loss in selectivity towards epoxide.

Recent developments in penta-, hexa- and heptadentate Schiff base ligands and their metal complexes

“…They also found applications in polymeric materials [66,67], sensors [26,68], organic photovoltaic materials [69], energy materials [70], nuclear medicine [71] and as components of pharmaceutically active cocrystals [72]. Schiff base complexes exhibit also remarkable catalytic activities for a wide variety of organic A c c e p t e d m a n u s c r i p t transformations [73][74][75][76][77][78][79][80][81][82][83][84][85][86][87]. For instance, the use, efficiency, scope and recyclability of a Cu (II) complex featuring an unsymmetrical N2O2-tetradentate Schiff-base ligand and its covalently poly(methyl) (methacrylate) (PMMA)-grafted counterpart were disclosed, for the first time, as catalysts in the copper-catalyzed azides to alkynes cycloaddition (CuAAC) [88][89][90] for the regioselective formation of a wide variety of 1,4-disubstituted 1,2,3-triazoles via "click" reactions of organic azides and terminal alkynes [91].…”

Manganese Ferrite Nanoparticles Modified by Mo(VI) Complex: Highly Efficient Catalyst for Sulfides and Olefins Oxidation Under Solvent‐less Condition

“…The atomic percentage ratios of Mo/Cl=0.43 (theoretical value 0.5), Mo/Br=0.44 (theoretical value 0.5), Mo/Si=0.43 (theoretical value 0.5), Mo/N=0.42 (theoretical value 0.5) and Fe/Mn=2 (theoretical value 2) are in agreement with the chemical composition of the particles. The XRD pattern of the MnFe 2 O 4 –Mo(VI) particles is seen in Figure C showing Bragg reflections of (111), (220), (311), (400), (422), (511), (440), (533) and (622) planes and matching well with the standard XRD pattern of cubic manganese ferrite NPs …”

“…According to our previous works on the catalytic activity of d‐block Schiff base complexes, a MnFe] 2 O 4 supported Mo(VI) Schiff base complex, MnFe 2 O 4 ‐Mo(VI), derived from 1,3‐bis(4‐bromo‐2‐carboxyaldehyde phenoxy)propane has been developed in the presented work (Figure ). The novel heterogeneous catalyst was tested for its ability to oxidize olefins and sulfides selectively into epoxides and sulfoxides in green solvent‐less condition.…”

CNRS Silver and Bronze Medals 2018

“…Szunerits is currently interested in materials (mostly based on graphene) for sensing and transdermal delivery as well as on the development of nanostructures against viral and bacterial infections. Her report on glycan‐modified nanodiamonds was featured on a cover of ChemNanoMat , and she is co‐author of a report in ChemistrySelect on the catalytic properties of MnFe 2 0 4 nanoparticles nodified with Schiff base complexes …”