Synthesis, characterization and immobilization of a new cobalt(ii) complex on modified magnetic nanoparticles as catalyst for epoxidation of alkenes and oxidation of activated alkanes†
Abstract
The [Co(2-hydroxy-1-naphthaldehyde)2(DMF)2] complex 1 was prepared and characterized by X-ray crystallography, successfully supported on modified Fe3O4 nanoparticles using tetraethylorthosilicate (TEOS) and (3-aminopropyl)trimethoxysilane (APTMS) and designated as Fe3O4@SiO2@APTMS@complex nanocatalyst. FT-IR, elemental analysis, XRD, VSM and TEM studies have been used to characterize the nanocatalyst. The catalytic activity of Fe3O4@SiO2@APTMS@complex was evaluated by the epoxidation of norbornene, cyclooctene, styrene, α-methyl styrene, trans-stilbene and limonene, with 50–100% conversions and 83–100% selectivities. Furthermore, it was found that Fe3O4@SiO2@APTMS@complex successfully catalyzes the oxidation of activated secondary alkanes such as fluorene, adamantane, diphenyl methane, and ethylbenzene with 40–100% conversions and 80–100% selectivities toward the corresponding products. Based on the obtained results, the heterogeneity and reusability of the catalyst seems promising.