Spectroscopic characterization of some tetradentate Schiff bases and their complexes with nickel, copper and zinc

Three ligands have been formed by the 1:2 molar condensation of o-phenylenediamine with salicyldhyde, 2-hydroxy-1-naphthaldhyde or o-hydroxyacetophenone. The potentially tetradentate ligands are N,N ' -bis(salicyldhyde)-o-phenylenediamine (SalophH(2)), N,N ' -bis(2-hydroxy-1-naphthaldhyde)-o-phenylenediamine (NophH(2)) and N,N ' -bis(o-hydroxyacetophenone)-o-phenylenediamine (AophH(2)), respectively. These ligands form complexes (1:1 molar ratio) with nickel, copper and zinc ions. The complexes have been characterized by IR, H-1 NMR, MS, uv/vis spectra in addition to elemental analysis. The spectral data of the ligands and their complexes with nickel, copper and zinc are discussed in connection with the structural changes which occur due to complexation.