ZnFe2O4@SiO2@n-pr@xanthine-Pr: as a highly versatile catalyst for the preparation of 1H-tetrazoles and sulfoxidation reaction

Abstract

Herein, a novel ZnFe₂O₄@SiO₂@n-pr@xanthine-Pr nanoparticle was successfully synthesized as a green catalyst, which contains the xanthine-Pr catalytic moiety on the surface of silica-coated zinc ferrite as the catalyst support. Then, ZnFe₂O₄@SiO₂@n-pr@xanthine-Pr were characterized by some physicochemical techniques such as Fourier-transformed infrared spectroscopy, X-ray powder diffraction, inductively coupled plasma, energy-dispersive X-ray spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis, and vibrating sample magnetometry (VSM). SEM patterns of ZnFe₂O₄@SiO₂@n-pr@xanthine-Pr show that the particle’s size is in nanometer dimensions. The preparation of 1H-tetrazole derivatives and oxidation of sulfides were efficiently performed through the catalytic performance of ZnFe₂O₄@SiO₂@n-pr@xanthine-Pr. The VSM analysis of the catalyst exhibits that it is recoverable by an external magnet; therefore, it can be reused several continuous times with negligible loss of catalytic properties or praseodymium leaching. Also, the catalytic reactions proceed in high turnover number and turnover frequency numbers, which proves high activity and selectivity in all catalytic experiments. The chemical and thermal stability as well as the heterogeneous nature of the catalyst was confirmed by a hot filtration experiment.