Copper(II) Schiff Base Complex Immobilized on Magnetic-Fe₃O₄ Nanoparticles for Selective Oxidation of Anthracene

A novel heterogeneous catalyst Fe3O4@SB@Cu that contains a copper(II) Schiff base complex covalently immobilised on Fe3O4 nanoparticles was synthesised. The prepared catalyst is well characterised by FTIR spectroscopy, UV-Visible spectroscopy, FE-SEM, TEM, VSM analysis, EDX, XRD analysis, TGA, CV technique, XPS and PL studies to confirm its structural and morphological features. The high BET surface area (117.34 m(2)/g) was achieved for particles with size 25-30 nm and saturation magnetisation of 43.4 emu/g. The catalytic potential of the synthesised catalyst Fe3O4@SB@Cu was investigated by employing H2O2 as an oxidant for the oxidation of anthracene to anthraquinone. Various parameters like catalytic loading, temperature and solvents were varied to determine the optimal catalytic conditions, and 96% yield of the product is obtained within 36 min when the reaction was performed in the acetonitrile solvent with 1.8% loading of the catalyst. The catalytic reaction was monitored by UV-Visible spectroscopy. Using an external magnet, the modified nanoparticles were easily retrieved from the reaction mixture and can be utilised for five more reaction cycles without the significant loss of activity or copper leaching.