Coordination chemistry of some new Cu(II), Ni(II) and Co(II) macroacyclic (N2O4) Schiff base complexes: X-ray crystal structure of Cu(II) complex

Six new Cu(II), Ni(II) and Co(II) macroacyclic Schiff base complexes [M^II(H₂L)](ClO₄)₂ (L = L¹ and L²) (I–VI) were prepared by the reaction of two new N₂O₄ Schiff base ligands in equemolar ratios. The ligands H₂L¹ and H₂L² were synthesized by reaction of 2-[2-(2-formyl phenoxy)ethoxy]benzaldehyde (A¹) and/or 2-[2-(3-formylphenoxy)propoxy]benzaldehyde (A²) and ethanol amine and characterized with IR and ¹H, ¹³C NMR spectroscopy. All complexes were characterized by microanalysis, IR and mass spectrometry, whereas complex I was also characterized by single crystal X-ray (CIF file CCDC no. 1020055). The X-ray structure of complex I revealed that all nitrogen and oxygen atoms of ligand (N₂O₄) have coordinated to the metal ion. However, Cu²⁺ ion is in six coordination environment that can bedescribed as a distorted octahedral geometry.