Synthesis, spectroscopic, and thermal analyses of binuclear mixed ligand Co(II) and Ni(II) complexes

Abstract

Two isostructural mixed ligand binuclear metal complexes, [Co₂(µ₂-H₂O)(µ₂-L₁)₂(L₁)₂(L₂)₂]0.5C₇H₈ (1) and [Ni₂(µ₂-H₂O)(µ₂-L₁)₂(L₁)₂(L₂)₂]0.5C₆H₆ (2) (L₁ = CCl₃COO⁻, L₂ = N,N,N′,N′-tetramethylethylenediamine(tmen)), have been synthesized and structurally characterized by X-ray crystallography. Complex 1 crystallizes in orthorhombic system with space group Pbcn and 2 crystallizes in orthorhombic system with space group Pbca. L₁ has two different coordination modes, µ₂-bidentate bridging-(0,0′) and monodentate-(0); L₂ coordinates in chelating mode (N,N′) in both 1 and 2. The coordination geometry around metals is highly distorted octahedral. The elemental, spectral (IR, diffused electronic spectra), physical (thermogravimetry, molar conductivity) and magnetic moment studies are reported. Molar conductance measurements of 1 and 2 in acetonitrile correspond to the non-electrolytic nature of the complexes.

Keywords:

• Cobalt(II)
• Nickel(II)
• Mixed ligand complexes
• X-ray crystallography

Acknowledgments

Ms Deepika Saini gratefully acknowledges the meritorious fellowship as a financial assistance from UGC, New Delhi, India. The project “Factoría de Cristalización, CONSOLIDER INGENIO-2010” provided X-ray structural facilities for this study.