The present study aims to assess the potential of three pyrimidine derivatives—namely, ethyl 4-[4-(dimethylamino)phenyl]-2-imino-6-methyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate (EDTP), 1-{4-[4-(dimethylamino)phenyl]-2-imino-6-methyl-1,2,3,4-tetrahydropyrimidin-5-yl}ethan-1-one (DITP), and 4-[4-(dimethylamino)phenyl]-2-imino-6-methyl--phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxamide (DPTP)—in protecting mild steel against acidic corrosion. The anti-corrosive effectiveness of these synthesized pyrimidine derivatives is evaluated using various electrochemical techniques. Based on the electrochemical findings, it is observed that all synthesized pyrimidine derivatives function as mixed-type inhibitors. Notably, DPTP demonstrates superior efficacy at 750 ppm (91.7 %) in comparison to EDTP (88.9 %) and DITP (88.4 %). Analysis utilizing the Langmuir isotherm model reveals the most precise correspondence with the studied derivatives, suggesting a mixed mode of adsorption involving both chemisorption and physisorption. Furthermore, a surface analysis investigation is conducted to assess the morphology of metallic surfaces exposed to varying inhibitor concentrations within an acidic environment. To corroborate the experimental findings, theoretical approaches including Monte Carlo simulation (MC simulation) and density functional theory (DFT) have been employed.

中文翻译：

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嘧啶衍生物作为低碳钢酸腐蚀的有效防腐剂：电化学和计算验证

本研究旨在评估三种嘧啶衍生物的潜力，即 4-[4-(二甲基氨基)苯基]-2-亚氨基-6-甲基-1,2,3,4-四氢嘧啶-5-甲酸乙酯 (EDTP) )、1-{4-[4-(二甲基氨基)苯基]-2-亚氨基-6-甲基-1,2,3,4-四氢嘧啶-5-基}乙-1-酮 (DITP) 和 4- [4-(二甲氨基)苯基]-2-亚氨基-6-甲基-苯基-1,2,3,4-四氢嘧啶-5-甲酰胺(DPTP)——保护低碳钢免受酸性腐蚀。使用各种电化学技术评估这些合成的嘧啶衍生物的防腐蚀效果。根据电化学结果，观察到所有合成的嘧啶衍生物都起到混合型抑制剂的作用。值得注意的是，与 EDTP (88.9%) 和 DITP (88.4%) 相比，DPTP 在 750 ppm (91.7%) 下表现出卓越的功效。利用朗缪尔等温线模型的分析揭示了与所研究的衍生物最精确的对应关系，表明涉及化学吸附和物理吸附的混合吸附模式。此外，还进行了表面分析研究，以评估在酸性环境中暴露于不同抑制剂浓度的金属表面的形态。为了证实实验结果，采用了蒙特卡罗模拟（MC模拟）和密度泛函理论（DFT）等理论方法。