Synthesis and Characterization of Some Cobalt (ІІ) and Copper (ІI) Complexes with N2O2 Ligands Derived from 2-Hydroxybenzaldehyde

Abstract

2-Hydroxybenzaldehyde has been reacted with 1,4-phenylendiamine and 1,2-phenylendiamine to give the N₂O₂ Schiff Base type ligands named N,N'-bis( salicylidene)-1,4-phenylenediamine (L'H₂) and N,N'-bis( salicylidene)-1,2-phenylenediamine (L''H₂). The structures of the ligands were elucidated by FT-IR, ¹H-NMR, ¹³C-NMR and UV-Vis electronic spectra. The coordination behavior of the (L'H₂) and (L''H₂) towards Cu(II) and Co(II) ions has been investigated. The reaction of the Schiff base ligands (L'H₂), (L''H₂) with cobalt (II) and copper (II) ions in 1:2 molar ratio afforded binuclear metal complexes.The changes in the selected vibration bands in FT-IR indicate that Schiff bases behave as N₂O₂ tetradentate ligands and coordinate to metal ions from phenolic oxygen atoms and azomethine nitrogen atoms. Characterization and structure elucidation of the prepared complexes were achieved by FT-IR, UV-Vis electronic spectra. The metal complexes exhibited different geometrical arrangements such as square planner and tetrahedral arrangements.

Keywords: 2-Hydroxybenzaldehyde, Schiff base, binuclear complexes, tetradentate ligands.