Synthesis, characterization, and multifunctional evaluation of a new Schiff base: Corrosion inhibition, biological activity, and computational studies

A novel Schiff base inhibitor, 4,4’-Bis (2-pyrrole carboxaldehyde) diphenyl diimino ether, was synthesized and comprehensively characterized by elemental analysis, FTIR,1H-NMR, and UV-Visible spectroscopy. This compound delivered exceptional corrosion inhibition for carbon steel in 1 M HCl, achieving 94.46%±0.01 efficiency at 72h through time-dependent enhancement and minimal temperature sensitivity, validated by gravimetric, potentiodynamic polarization, electrochemical impedance spectroscopy, and SEM/EDS analyses across multiple experimental factors. This inhibitor adsorbs onto the steel surface, forming a protective layer, and follows the Langmuir adsorption isotherm. DFT quantum studies and molecular dynamics simulations correlated these results with superior Fe (110) adsorption via multiple active sites (dual imines, oxygen, pyrrole, aromatics). Additionally, the compound exhibited potent broad-spectrum antibacterial activity against Gram+/Gram-/yeast pathogens with favorable pharmacokinetic properties (Lipinski/Veber compliance). The molecular docking study revealed high binding affinity and significant interactions between the Schiff base and E. coli MsbA protein (binding energy −7.3 kcal/mol).