Synthesis and Structural Characterizations of Ternary Iron(Ⅱ) Mixed Ligand Complex: Low Cost Materialsas a Precursor for Preparation of Nanometric Fe_2O_3 Oxide

The reaction of the ligands, ethylenediaminetetraacetic acid terasodium salt (Na₄EDTA) and N-N heterocyclic diamines like2,2’-bipyridine (bipy) with iron(Ⅱ) sulfate with 1∶2∶2 stoichiometric ratios form the mononuclear ternary complex of formulae, [Fe₂(EDTA)(bipy)₂] at pH~7. The FTIR and Raman laser spectra of the iron(Ⅱ) complex show that 2,2’-bipyridine is present asa bidentate ligand and the ethylenediaminetetraacetic acid terasodium salt as monodentate carboxylate anion. The electronic spectra and magnetic moments data suggest the six coordination number. It has two iron(Ⅱ) centers in octahedral environments, which are interlinked by carboxylato-O atoms of ethylenediaminetetraacetate and by nitrogen atoms of the two 2,2-bipyridine ligands in a chelating mode. Thermal analysis study show thatiron(Ⅱ) complex containing EDTA and 2,2’-bipyridine on its thermalde composition form the corresponding Fe₂O₃ oxide in nano size at the temperature range ~475 ℃. The iron(Ⅱ) complex was performed as a convenient low cost precursor for the preparation of Fe₂O₃ nanoparticles by the the thermal decomposition method. The iron(Ⅲ) oxide composition has been discussedusing FTIR, X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX).