Synthesis and Electrochemistry of M(II) N2O2 Schiff Base Complexes: X-Ray Structure of {Ni[Bis(3-chloroacetylacetone)ethylenediimine]}

The synthesis and characterization of [Ni(BCE)] and [Cu(BCE)] (where BCE = bis(3-chloroacetylacetone)ethylenediimine) are described. The coordination geometry of [Ni(BCE)] was determined by X-ray crystallography. It was found to be planar and four coordinate in the solid state. The electrochemical properties of M(Chel), where M = Co(II), Ni(II) and Cu(II), and Chel = BAE (bis(acetylacetone) ethylenediimine), BBE = bis(benzoylacetone) ethylenediimine, BFE (bis(1,1,1-triflouroacetylacetone) ethylenediimine and BCE ligands were investigated in DMF and DMSO as solvents. The oxidation potentials changed from left to right in the periodic table in the trend: Co < Ni < Cu, while the reduction potentials changed according to the trend: Ni > Co > Cu. The oxidation potentials of M(II) to M(III) (M = Ni and Cu) increased according to the Schiff base ligands in the trend: BAE < BBE < BCE < BFE, while the reduction potentials followed a reverse trend: BAE > BBE > BCE > BFE. The oxidation potentials of M(II) to M(III) increased according to the solvent in the trend: DMSO < DMF.