<p>The present work involves the synthesis of six Schiff base ligands through the condensation of 2-hydroxy-1,2-di(phenyl)ethanone and diamine derivatives. Microelemental analysis, UV–Visible, FT-IR, NMR, EI, and Mass spectral studies were employed to characterize all the synthesized compounds. As very effective corrosive inhibitors of mild steel corrosion, they were used after their identification and biological assessment. The weight loss method was used to evaluate the inhibitory efficiency. Additionally, the surface morphology was examined using a scanning electron microscope (SEM). The calculated Gibbs free energy value validates the chemical nature of the adsorption, and the adsorption of BPA on the carbon steel surface was consistent with the Langmuir adsorption isotherm model. The charge in the impedance parameters (Rt and Cdl) with BPA concentrations was indicative, according to the EIS data. A protective layer forms on the surface of carbon steel as a result of this molecule's adsorption. Surface morphology investigations have also been used to support the electrochemical data. According to EIS analysis, resistance increased as inhibitor concentration increased, indicating the creation of a protective layer at the C-S/HCl interface. Polarisation curves show that the inhibitor impacts both the cathodic and anodic corrosion currents. Several factors influence the inhibition efficiency of the inhibitor, including the concentration, molecular weight, double bond conjugation, and amount of nitrogen it contains. The hydroxyl and N, N-dimethylamino substituent ligand achieved 98% efficiency. Based on the zone of inhibition, the antibacterial activity of the agar cup plate method against Escherichia coli, Staphylococcus aureus, and Candida albicans was measured.</p>