Comparison the anticorrosion behavior of three symmetrical Schiff-base ligands: experimental and theoretical studies

The effect of structural difference of synthesized symmetrical Schiff bases, named 2,2′-((1Z,1′Z)-((piperazine-1,4-diylbis(2,1-phenylene))bis(methanylylidene))bis(azanylylidene)) (M1), 2,2′-((1Z,1′Z)-((( propane-1,3-diylbis(oxy))bis(2,1-phenylene))bis(methany lylidene))bis(azanylylidene)) diethanol (M2), and 2,2′-((1Z,1′Z)-(((1,2-phenylenebis(oxy))bis(2,1-phenylene))bis (methanylylidene))bis (azanylylidene))diethanol (M3), on protection of steel in 1 M HCl has been investigated. Weight loss method, electrochemical impedance measurements, and current transient tests were used. The outcome demonstrated that three ligands are efficient corrosion inhibitors but M3 illustrated the excellent inhibiting specification for this system, with a maximum IE of about 94% contained only 2 × 10 −3 M. The outputs gained by density functional theory methods were consistent with experimental results. Specimen surfaces were characterized using an atomic force microscopy. Graphical abstract