Synthesis, structure and spectroscopic properties of the trinuclear cobalt(II) and nickel(II) complexes based on 2-hydroxynaphthaldehyde and bis(aminooxy)alkane

• [{CoL(DMF)}2(OAC)2Co] has been synthesized and characterized structurally.
• [{NiL(H2O)}2(OAc)2Ni]⋅2C2H5OH has been synthesized and characterized structurally.
• The two complexes form novel 2D hydrogen-bonding supramolecular structure.
• Results are very important to coordination chemistry and supramolecular chemistry.

A new Salen-type bisoxime ligand, 2,2′-[ethylenedioxybis(nitrilomethylidyne)]dinaphthol (H2L) and its corresponding cobalt(II) and nickel(II) complexes, [{CoL(DMF)}2(OAC)2Co] and [{NiL(H2O)}2(OAc)2Ni]⋅2C2H5OH have been synthesized, and characterized by elemental analyses, IR spectra, UV–vis spectra, TG–DTA and molar conductance measurements, etc. The X-ray crystal structure studies reveal that the cobalt(II) and nickel(II) complexes are symmetric trinuclear structures. All of the M(II) (Co(II) or Ni(II)) ions for the cobalt(II) or nickel(II) complexes are six-coordinated and have slightly distorted octahedral coordination geometries.

Two new supramolecular trinuclear complexes, namely [{CoL(DMF)}2(OAC)2Co] and [{NiL(H2O)}2(OAc)2Ni]⋅2C2H5OH, with a new Salamo-type ligand (H2L = 2,2′-[ethylenedioxybis(nitrilomethylidyne)]dinaphthol) have been synthesized and structurally characterized by elemental analyses, IR, UV–vis, TG–DTA and X-ray crystal structure analyses, etc. Some new results are very important to modern coordination chemistry and supramolecular chemistry. In the crystal structure, the cobalt(II) or nickel(II) complex is linked by intermolecular CH⋯O (or CH⋯π) and π–π* stacking interactions into a novel 2D infinite supramolecular structure.Figure optionsDownload as PowerPoint slide