The inhibition effect of three novel Schiff bases on corrosion of carbon 
steel was studied in 1 M HCl solution. The inhibition efficiency was 
measured by weight loss, potentiodynamic polarization and 
electrochemical impedance spectroscopy (EIS) methods. The obtained 
results showed that the prepared Schiff bases are very good corrosion 
inhibitors. The adsorption of inhibitors on carbon steel surface obeys 
Longmuir adsorption isotherm. The adsorption of these Schiff bases 
involves two types of interaction physical and chemical adsorption. The 
inhibition efficiency increases with increasing inhibitor concentration and 
temperature. Quantum chemistry calculations for the geometrical full 
optimization of the inhibitors were calculated.