Effect of alkyl chain length on the corrosion inhibition performance of 2-thioxo-2,3-dihydroquinazolin-4(1H)-one derivatives for carbon steel in HCl solution

in the inhibited solution of Q-C4. The surface of carbon steel was examined using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and Fourier-transform infrared spectroscopy (FT-IR), demonstrating the formation of a protective layer on the CS surface, mitigating the corrosion. Finally, the adsorption affinity of these compounds on the carbon steel surface was theoretically examined utilizing quantum calculations. The outcomes of the theoretical study in quantum chemistry were corroborated by data from chemical and electrochemical methods.