Synthesis, characterizations of co(II) complex of n,n’bis(Salicylidene)ethylenediamine as anti corrosion screening / Nurfarhana Husin

The synthesis, characterizations and anti corrosion activity on Schiff base ligand and its Co(II) complex namely N,N’-Bis(salicylidene)ethylenediamine and N,N’-Bis(salicylidene)ethylenediamine Co(II) complex was conducted in this research project. N,N’-Bis(salicylidene)ethyelediamine were synthesized from the reaction of salicylaldehyde with ethylenediamine undergo further insertion with Co(II) metal center to produce N,N’-Bis(salicylidene) ethylenediamine Co(II) complex. The ligand and complex were characterized by using elemental analysis, UV-Vis and IR spectroscopy. Through the IR spectra, it was found that the Co(II) metal coordinate through the azomethine-N and phenolic-O producing a bidentate ligand. From the UV-Vis data showed the charge transfer from nonbonding orbital of azomethine nitrogen to half-filled d-orbitals of Cobalt(II) at 382 nm. The anti corrosion screening has been done with different concentration which are 0.1 M, 0.01 M and 0.001 M of inhibitors. The results showed that the inhibition efficiency of ligand and complex were increased with increased in concentration of inhibitors. However, the N,N’-Bis(salicylidene)ethylenediamine ligand possess a good corrosion inhibitor compared to the complex. This maybe was due to the presence of lone pair of electrons in nitrogen and oxygen atoms along with the delocalized π electron. The chemical adsorption of metal complex was less than ligand because the lone pair was shared with the metal ion that was reduced the effective adsorption on mild steel surface.