Synthesis and characterization of molybdenum (VI) complex immobilized on polymeric Schiff base‐coated magnetic nanoparticles as an efficient and retrievable nanocatalyst in olefin epoxidation reactions

Abstract

In this study, a new polymeric functionalized magnetic nanocatalyst containing a molybdenum Schiff base complex was prepared using a few consecutive steps. Poly (methylacrylate)‐coated magnetic nanoparticles were synthesized via radical polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups with hydrazine. Polymeric functionalization efficiently provides the advantage that more catalytic units can be grafted on the surface of magnetic nanoparticles. The functionalization process was continued with salicylaldehyde which introduced Schiff base groups on to the surface of the polymeric support. In the final step, the desired catalytic system was prepared via complexation of the Schiff base groups with MoO2(acac)2. The resulting nanoparticles were characterized by infrared spectroscopy, powder X‐ray diffraction, scanning and transmission electron microscopy, elemental analysis, inductively coupled plasma optical emission spectrometry, vibrating sample magnetometry and thermogravimetric analysis. This heterogenized catalytic system was also found to be highly active, sustainable and recyclable nanocatalyst in alkene epoxidation. Eventually, the attractive features of the synthesized catalyst such as simple work‐up, good stability, magnetic separation, high TOF and high surface area; make it appropriate for oxidation reactions.

A Guideline for Effectively Synthesizing and Characterizing Magnetic Nanoparticles for Advancing Nanobiotechnology: A Review

“…Even though FTIR provides information regarding the presence of binding on the surface and its type, it does not provide volumetric information, such as mass to mass ratio of the magnetic nanoparticles to its coating. This limitation can be addressed using thermal gravimetric analysis (TGA), which provides information about the composition and mass of the coating [100][101][102]. This technique increases the sample temperature while monitoring the mass change of the sample as it changes due to the degradation of components.…”