Thermal Studies of Iron (II) Schiff Base Complexes: New Precursors for Preparation of α-Fe2O3 Nanoparticles via Solid-State Thermal Decomposition

Abstract

In this research study, four iron (II) complexes of tetradentate N₂O₂ Schiff base ligands with the general formula of Fe((MeO-bph)2 Am) (Am=1,2-ethyelenediamine (1), 1,3-propanediamine (2), 1,4-buanediamine (3) and 2,2-dimethyl-1,3-propanediamine (4) were synthesized and characterized using the elemental analysis (CHN) and FT-IR spectroscopy. Thermal properties and decomposition stages of all the complexes were evaluated. Finally, all complexes were decomposed at 600 °C for 3 h and the dark precipitates were characterized using the FT-IR, XRD and SEM. FT-IR and XRD results revealed that the precipitate were the pure phase of rhombohedral of magnetite (<em>α</em>-Fe₂O₃) nanoparticles. The SEM images showed that, the morphology of the precipitate was a relatively spherical shape and average diameter of 40-70 nm. The results of the thermogravimetric analysis the iron (II) complexes showed that the complexes 1–4 were stable until 140-200 °C. However, after that, all the complexes 1–4 decomposed in two stages at various temperatures.