Oxovanadium(IV)‐salophen covalently immobilized on silica‐coated Fe₃O₄ nanoparticles: A magnetically recoverable nanocatalyst for the selective oxidation of sulfides

Abstract

The current study introduces an approach toward the development of heterogeneous, magnetically recoverable oxovanadium(IV)‐salophen complex to employ in the selective oxidation of sulfides using H2O2 as oxidant. A salophen ligand containing hydroxyl functional group was synthesized, which is conducive to successful, covalent immobilization of metal complex onto the silica‐modified Fe3O4 magnetic nanoparticles (SMNPs). This type of metal anchoring is achieved through an intermolecular condensation reaction. The in‐depth investigation on the catalyst (Fe3O4@SiO2@VO(salophen)) productivity and lifetime in the oxidation of a wide range of linear and aromatic sulfides is well represented and discussed. The use of the current catalyst in the selective oxidation of prototype substrate (methyl phenyl sulfide) resulted in an appreciable increase in the selectivity toward the desired sulfoxide (92%) and conversion rate (95%) compared with similar studies, reported to this day. Analytical techniques such as field emission scanning electron micrograph (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD) analysis, and inductively coupled plasma optical emission spectrometer (ICP‐OES) provided data on structural/compositional characterization of materials in catalyst preparation steps.

Fe3O4@SiO2@CSH+VO3− as a novel recyclable heterogeneous catalyst with core–shell structure for oxidation of sulfides

“…Vanadium is one of the transition metals in the third row of the periodic table, exhibiting various coordination numbers. It is abundantly present on the earth's surface, surpassing the quantities of copper and palladium, and is associated with fewer adverse effects on the environment compared to many other metals 41 – 43 . Up to now, various catalytic systems based on transition metals and hydrogen peroxide have been explored for the conversion of sulfides to sulfoxides.…”

Fe3O4@SiO2@CS.HCl.VO3 as A Novel Recyclable Heterogeneous Catalyst with Core-Shell Structure for Oxidation of Sulfides

“…This metal is present on the surface of the earth in a much larger amount than copper and palladium and has less adverse effects on the environment than many other metals. [41][42][43] Up to now, for the conversion of sul de to sulfoxide, various catalytic systems based on transition metals and hydrogen peroxide have been mentioned, which unfortunately suffer from disadvantages such as environmental hazards, di cult reaction methods, long time, low e ciency and using expensive reagents. 44 According to the mentioned materials, the need for the synthesis and design of heterogeneous nanocatalysts that are inexpensive, compatible with the environment, recoverable, stable and with high activity is always one of the concerns of researchers.…”