Insights into the Corrosion Inhibition Performance of Three 2-Isoxazoline-γ-Lactones for Carbon Steel in Acidic Medium: Linking Molecular and Experimental-Level Information with Microscopic-Scale Modeling

The corrosion inhibition properties of three spiro-isoxazoline derivatives, namely 3,4-diphenyl-1,7-dioxa-2-azaspiro[4.4]non-2-en-6-one (DDA), 3-phenyl-4-(p-tolyl)-1,7-dioxa-2-azaspiro[4.4]non-2-en-6-one (PDA) and 4-(4-methoxyphenyl)-3-phenyl-1,7-dioxa-2-azaspiro[4.4]non-2-en-6-one (MDA) on carbon steel in 1.0 mol/L HCl acid medium were experimentally computationally investigated. experimental results showed that the inhibitory efficiency reached remarkable values 76.26, 80.31, 82.91%, respectively, for DDA, PDA MDA at a maximum concentration 10−3 mol/L. potentiodynamic polarization curves (PPCs) investigated compounds had mixed type character, controlling both anodic cathodic reactions. In addition, electrochemical impedance spectroscopy (EIS) indicated addition increasing tested to solutions led significant increase resistance steel, which was accompanied with simultaneous decrease double layer capacitance. On other hand, morphological study metal surface by scanning electron microscope (SEM) energy dispersive X-ray (EDX) confirmed effective protection inhibitors against through formation protective film its surface. adsorption characteristics assessed microscopic level using Density Functional Based Tight Binding (DFTB) simulation, revealed covalent bonds between inhibitors’ atoms Fe atoms. Furthermore, additional insights into compounds’ reactivity configurations obtained from global descriptors Monte Carlo simulation. present work’s outcomes are interesting further design performance evaluation organic environments.