Novel pyrazolone–thiophene Schiff base functionalized Fe3O4 nanocomposite: core–shell structure and multi-technique characterization

Abstract

This work reports the synthesis and structural characterization of a new magnetic nanocomposite, Fe₃O₄@PyTh, created by forming a surface-functionalized magnetic nanocomposite with a pyrazolone–thiophene Schiff base (PyTh). The ligand was produced via a one-pot condensation reaction and attached as a shell on the Fe₃O₄ core, forming an organic–inorganic hybrid interface. Comprehensive characterization using Nuclear Magnetic Resonance (NMR), Fourier-Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), Transmission Electron Microscopy (TEM), and Selected Area Electron Diffraction (SAED) confirmed successful ligand attachment, the preservation of the cubic spinel Fe₃O₄ core, and the formation of a uniform organic shell. TEM analysis showed an increase in size from 7.5 to 9.1 nm after PyTh modification, while EDX mapping confirmed the presence of nitrogen, sulfur, and carbon, indicating effective functionalization. This study highlights the structural stability and hybrid nature of the Fe₃O₄@PyTh surface-functionalized magnetic nanocomposite, offering experimental structural insights into Schiff base functionalization as an adaptable route for designing advanced magnetic hybrid materials.