High incorporation of magnetite nanoparticles inside tetraaza macrocyclic Schiff base cavity: spectroscopic characterization and modeling by DFT calculation

This work presents a simple synthesis of tetraaza macrocyclic Schiff base ligand (C40H28N4), its complex [(C40H28N4)@Fe(II)], and novel magnetite Fe3O4NPs incorporated inside cavity [(C40H28N4)@Fe3O4NPs] by the co-precipitation method in order to obtain well-dispersed nanoparticles, controlled size prevent aggregation Fe3O4 NPs due strong dipole–dipole magnetic attractions interactions between particles. The characterization structural identification were carried out X-ray spectroscopy as well 1H NMR, 13C DEPT 135 NMR spectroscopy, FT-IR, UV–visible, EDX, TGA, finally VSM using both experimental theoretical methods. XRD measurements indicate that presence Schiff's bases does not modify crystal structure nanoparticles (11.05 nm). All spectra suggested success all structures with high purity. FTIR was used illuminate tetrahedral octahedral sites their coordination imine (C = N) macrocyclic. UV–visible frontier molecular orbitals (FMOs) title compounds calculated at TD-DFT/CAM-B3LYP-D3/6–311 G (d, p) level theory. corresponding result yield shows good agreement data. morphological SEM, which revealed shape generally spherical. SEM images also show prepared situ able form stable complexes. Thermal TGA there are 64% formed situ, corresponds grafting density 25 mmol.g−1. analysis displays similar hysteresis loop compared free NPs, confirmed ferromagnetic character significant decrease saturated magnetization.