Molybdenum Schiff Base Complex Covalently Anchored to Silica-Coated Cobalt Ferrite Nanoparticles as a Novel Heterogeneous Catalyst for the Oxidation of Alkenes

Abstract

Silica-coated cobalt ferrite nanoparticles were prepared and functionalized with Schiff base groups to yield immobilized bidentate ligands. The functionalized magnetic nanoparticles were then treated with Mo (O 2 ) 2 (acac) 2 , resulting in the novel immobilized molybdenum Schiff base catalyst. The as-prepared catalyst was characterized by X-ray powder diffraction, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, and inductively coupled plasma atomic emission spectroscopy. The immobilized molybdenum complex was shown to be an efficient heterogeneous catalyst for the oxidation of various alkenes using t-BuOOH as oxidant. This catalyst, which is easily recovered by simple magnetic decantation, could be reused several times without significant degradation in catalytic activity.

Recent Advances in Facile Liquid Phase Epoxidation of Light Olefins over Heterogeneous Molybdenum Catalysts

“…[41] (m) Mo-salenSi@Si-MNPs. [42] [43] (MoO 2 salpr@MCM-41), [44] MoO 2 Sal@MCM-41, [45] results showed that MoO 2 Sal/APTSCMNPs are more active in cyclohexene epoxidation in the same reaction conditions due to the fact that MoO 2 Sal/APTSCMNPs has better site isolation, insignificant pore diffusion limitations and relatively strong interaction between the chelating ligand and the Mo center.…”

“…(l) MoO 3 (sal‐phz)Fe 3 O 4 ‐SBA‐15(3B) . (m) Mo‐salenSi@Si‐MNPs . (n) (MoO(O 2 ) 2 (phox)/Fe 3 O 4 ‐SBA .…”

“…VSM results showed that the saturation magnetization for the Fe 3 O 4 nanoparticles and catalysts 2 A and 3B are 60.9, 54.8 and 45.6 emu g À 1 , respectively (Figure 3A, 3B, Table S1, #72-77). Kooti et al [42] prepared a novel immobilized Mo Schiff base catalyst ( Figure 3m) which is active in cyclooctene epoxidation (Y = 68 %, Table S1, #78). They first functionalize the silica-coated cobalt ferrite nanoparticles with Schiff base groups.…”

New magnetic supported hydrazone Schiff base dioxomolybdenum (VI) complex: An efficient nanocatalyst for epoxidation of cyclooctene and norbornene

“…[48][49][50][51] Regarding the application of magnetically separable catalysts, there are several reports that investigate the catalytic role of immobilized Mo complex on magnetic nanoparticles in the oxidation of alkenes. [52][53][54][55][56] According to this background, in this study, we report the synthesis and characterization of a new dioxomolybdenum complex with tridentate hydrazone Schiff base ligand ((2-hydroxy-5-nitrobenzylidene) benzhydrazide), followed by immobilization on the modified Fe 3 O 4 nanoparticles. The catalytic activities of both homogeneous and heterogeneous catalysts in the oxidation of various alkenes are evaluated.…”

Immobilized magnetic nano catalyst for oxidation of alcohol

“…However, the main drawback of these homogeneous catalysts is the necessity of their separation from the reaction mixture at the end of the reaction. Immobilization of Schiff base complexes to the magnetic nanoparticle support via covalent attachment provides facile separation of the catalyst during the reaction by external magnet [3]. The magnetic support offers high catalytic efficiency and better recycling without having the inherent problems of leaching of complex/ligand during the reaction.…”