Preparation and Characterization of Co(II), Ni(II),Cu(II) and Zn(II) Complexes with Unsymmetrical Tetradentate Schiff Bases Ligands

Complexes of Co(II), Ni(II),Cu(II) and Zn(II) with unsymmetrical tetradentate schiff bases ligands H₂L¹ =2-(1Z)- (8-(2-hydroxy benzylidene amino)naphthalen-1-ylimino) methyl) -6- methoxy phenol, H₂L² =2-((E) -1-(8-(Z)-2- hydroxyl benzylidene amino) naphthalen -1- ylimino) ethyl) phenol and H₂L³= 1-((8-((Z) -2-hydroxy benzylidene amino) naphthalen -1- ylimino) methyl) naphthalene-2-ol, have been prepared in (1:1) (L: M) molar ratio and characterized by elemental analysis, molar conductance, spectral method (I.R, electronic, ¹H-NMR), magnetic measurements and metal content analysis. The spectral data suggest that the ligands behave as a dibasic tetradentate ligands with ONNO donor, and coordinate with the metal ion to form mononuclear complexes via the oxygen and nitrogen atoms of the phenolic group and azomethine group respectively. Conductivity data in DMF solution showed that all complexes are non-electrolyte. Magnetic moment and electronic spectra data suggested square planar geometry for all complexes .