Selective and Efficient Olefin Epoxidation by Robust Magnetic Mo Nanocatalysts

Iron oxide magnetic nanoparticles were synthesized with different sizes (11 and 30 nm). Subsequently they shelled a silica layer allowing grafting of an organic phosphine ligand that coordinated to the [MoI2(CO)3] organometallic core. The was prepared by Stöber method using either mechanical (both 11 nm nanoparticles) or ultrasound (30 only) stirring. latter once coated obtained less aggregation, which beneficial for final material holding moiety. Mo loadings found be 0.20, 0.18, 0.34 mmolMo·g−1 MNP30-Si-phos-Mo,MNP11-Si-phos-Mo, MNP30-Sius-phos-Mo, respectively, ligand-to-metal ratio reaching 4.6, 4.8, 3.2, same order, confirming coordination moieties two phos ligands. Structural characterization from powder X-ray diffraction (XRD), scanning electron microscopy (SEM)/ transmission (TEM) analysis, Fourier-transform infrared (FTIR) spectroscopy data confirmed successful synthesis all nanomaterials. Olefin epoxidation several substrates catalyzed these nano-hybrid materials tert-butyl hydroperoxide (tbhp) as oxidant, achieved very good results. Extensive testing catalysts showed are highly active, selective, recyclable, efficient concerning oxidant consumption.