Novel Azo-benzoyl acetone metal complexes for inhibition of atmospheric steel corrosion

The high concentration of corrosive elements in the air causes atmospheric corrosion of metals, and this often occurs in industrial cities. It causes a variety of materials to be destroyed, mainly metals and their alloys. Therefore, a New 2-((1H-indazol-5-yl) diazenyl)-1-phenylbutane-1,3-dione ligand (L) and its divalent cobalt, nickel, and copper complexes were synthesized and characterized using CHN, ICP, m, XRD, TGA, magnetic moment measurements, and FT-IR, 1H-NMR,13C-NMR, mass, and UV-Vis spectroscopy. Through the nitrogen atom of the azo group and one oxygen atom of the carbonyl group, the ligand performs the function of a bidentate ligand. From the characterization and theoretical results, it was found that Co (II) and Ni (II) have an octahedral geometry, whereas the Cu (II) complex has a tetrahedral structure. The average particle size falls between 0.16 -0.48 nm. The activity of ligand and its metal complexes as inhibitors to reduce the rate or prevent atmospheric corrosion of iron was investigated. Materials Studio 2017 software was used to study the adsorption on the iron (110) surface. From the adsorption energy data, the % IE of the ligand and the complexes are arranged as Cu (II) complex > L > Ni (II) complex > Co (II) complex. SEM analysis proved that the specimen covered with Cu (II) complex has a good inhibitory effect that slows down the rate of corrosion compared with the blank and untreated specimen. Highlights The Azo- β-diketone dye and its divalent cobalt, nickel, and copper complexes were synthesized and characterized. The activity of these compounds towards the inhibition of the iron steel corrosion was investigated. The Cu (II) complex revealed the highest rate of corrosion inhibition. The DFT and Molecular Materials Studio software were applied.