Synthesis and electrochemistry of M(II) N2O2 schiff base complexes: X-Ray structure of {Ni[Bis(3-chloroacetylacetone)ethylenediimine]}

Abstract

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.

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“…Scheme 1: Coordination modes of β-diketone [4] X-ray crystallography discovered additional patterns of these types of complexes due to the development of X-rays apart from the common classical O,O-bidentate chelates [5]. β-diketones and their complexes are characterized and extensively studied by 1 H-NMR, 13 C-NMR, IR, UVvisible spectroscopies, X-ray diffraction, cyclic voltammetry, and thermal analysis techniques [6][7][8][9].…”

Characteristic Studies of Hexamethylene Diamine Complexes

“…The presence of ion pair on the nitrogen atom of imino group enables the coordination of numerous metal cations [5]. Transition metal complexes with oxygen and nitrogen donor Schiff bases are of particular interest because of their ability to possess unusual configuration that is structurally labile and their sensitivity to molecular environments [6,7]. Schiff base can also accommodate different anions of the same center metal involving various coordination modes, thereby allowing successful synthesis of homo-and heterometallic complexes with varied stereochemistry.…”

“…Solid State of the Elictrical Conductivity for ligand (HBS) and its metal complexes(1)(2)(3)(4)(5)(6) Compound Tc ( ∘ K) 1 (eV) at lower temp.…”