Manganese(II) complexes with bis(3-halo-2-hydroxy- 5-methylacetophenone)ethylenediamine; structure, characterization and redox behavior

Abstract

A series of manganese(II) complexes containing tetradentate Schiff-base ligands have been synthesized. The Schiff-base ligands were obtained by condensation of salicylaldehyde, 2-OH acetophenone or 2-OH, 3-X, 5-methyl acetophenone with ethylenediamine (X = Cl, Br, I). The complexes have been characterized by elemental analysis, IR, UV-VIS, ESMS, EPR spectroscopy, cyclic voltammetry and thermal analysis. The cyclic voltammograms of the complexes exhibit quasi-reversible behavior. The electrochemical potentials are influenced by the methyl and halogen atoms grafted on the ligand molecules. An EPR spectrum for the polycrystalline sample shows one broad isotopic signal as compared with the six lines for frozen solution in DMF.

Keywords:

• Manganese(II) complexes
• Schiff bases
• Synthesis
• Characterization
• Cyclic voltammetry
• EPR
• Magnetic and thermal studies