Preparation, Characterization, and Application of Preyssler Heteropoly Acid Immobilized on Magnetic Nanoparticles as a Green and Recoverable Catalyst for the Synthesis of Imidazoles

Resumo

An efficient, magnetically separable catalyst was synthesized by immobilization of Preyssler heteropoly acid (HPA) on Ni_0.5Zn_0.5Fe₂O₄ magnetite nanoparticles (MNPs) coated with hydroxyapatite (HA). The catalyst was characterized by scaning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR, energy dispersive spectroscopy (EDS), and TGA. Activity of this catalyst was tested in the synthesis of imidazole derivatives via one-pot three-component condensation of [9,10]-phenanthraquinone with aryl aldehydes and ammonium acetate at room temperature under solvent-free conditions.