CoFe2O4@SiO2–HClO4 magnetic nanoparticles: synthesis and its application in catalysis

Nanostructured catalysts represent a new frontier between homogeneous and heterogeneous catalysis. Nanocatalysts and nanocatalysis have received intensive attention over the past two decades, because of high activity and selectivity. Owing to this, in the present research work we utilized nanoparticles to improve the catalytic properties of a material. However, the isolation and recovery of these tiny nanoparticles from the reaction mixture are not easy. To overcome this issue, the use of magnetic nanoparticles has emerged as a viable solution; their insoluble and paramagnetic nature enables easy and efficient separation of the catalysts from the reaction mixture with an external magnet. In the present study, the microwave-assisted, three-component reaction between aryl aldehyde, ammonium acetate, and aryl 1,2 diketone that led to the synthesis of 8-phenyl-7H-acenaphtho[1,2-d]imidazoles in the presence of magnetically recoverable nanocatalyst has been described (CoFe 2 O 4 @SiO 2 –HClO 4 ). Characterization of magnetic nanoparticles was carried out with FT-IR, XRD, SEM-EDX, TEM, TGA-DSC, and VSM techniques. The advantages of the present protocol are a simple method of catalyst preparation, high yield of desired products, short reaction time, and easy magnetic recovery and reusability of catalyst. These features provide attractive objectives for the present study. Graphical abstract