Synthesis, and Characterization of Metal Transition Complexes Derived from the Schiff Base Ligand N,N'-Bis (5-bromosalicylidene)-Propane-1,2-Diamine (H2L)

Abstract

Five new transition metal complexes [Mn(L)(Cl)] (1), [Fe(L)(Cl)] (2), [Co(L)(H2O)2] (3),  [Ni(L)(H2O)] (4) and [Cu(L)] (5), are synthesized from the Schiff base ligand N,N'-Bis(5-bromosalicylidene)-propane-1,2-diamine (H2L) which derived from the condensation of 5-bromosalicylaldehyde with propane-1,2-diamine in methanol. The complexes are characterized by elemental analysis, FTIR and UV-visible spectroscopies, conductivity and magnetic moment measurements. The results show that the complexes 1-5 are mononuclear neutral electrolytes in DMF. The dinegative tetradentate ligand is coordinated to the metal ion through two phenolate oxygen atoms and two azomethine nitrogen atoms. Octahedral geometry is proposed for complex 3, square planar geometry is proposed for complexes 4 and 5 and square pyramidal geometry is proposed for complex 1 and 2. The structures of complexes 1 and 5 were solved by single crystal X-ray diffraction. Complex 1 crystallizes in a monoclinic system, with space group P21/c, while complex 5 crystallizes in a monoclinic system, with space group C2/c.