Design, Synthesis and Physico-Chemical Investigation of the Iron (II) Complexes Containing Heterocyclic Nitrogen Donor Ligands

A number of iron metal complexes of type [FeL₄(H₂O)₂]SO₄ where L=hetero cyclic nitrogen donor ligands (imidazole, pyridine, piperadine piperazine, indole, benzimidazole, benzotriazole, triazole, quinoline, iso-quinoline, carbazole) have been synthesized and characterized. These complexes are soluble in ordinary organic solvent. The conductivity data shows that these complexes are 1:1 electrolytic in nature. The IR spectra reveal the coordination of nitrogen of the ligand to central iron metal atom. The mass spectra for benzimidazole complex shows the molecular ion peak at 660 and base peak at 119. The thermal decomposition studies indicate the presence of water molecule which is associated to central metal ion. The loss of water molecule and decomposition of sulphate ion occurs at 250°c. Then after 100°c imidazole molecule is removed one by one, giving the Fe3O4 as the final product.