Abstract The corrosion inhibition properties of two newly synthesized Quinoline derivatives5-((2-(4-dimethylamino)phenyl-1H-benzo[d]imidazol-1-yl)methyl)quinolin-8-ol (Q-N(CH3)2) and 5-((2-(4-nitrophenyl)-1H-benzo[d]imidazol-1-yl)methyl)quinolin-8-ol (Q-NO2) on mild steel (MS) in 2.0 M H3PO4 solution has been evaluated by weight loss (WL), Tafel polarization and Electrochemical Impedance Spectroscopy (EIS). The experimental findings reveal that these organic compounds performed as good corrosion inhibitors in 2.0 M H3PO4. The inhibition efficiency increased with increasing of quinoline derivatives concentration. The potentiodynamic polarization studies showed that Q-N(CH3)2 and Q-NO2 acts as a mixed type of inhibitors. The EIS studies showed that the charge transfer resistance increases with the inhibitor concentration and the adsorption of Q-N(CH3)2 and Q-NO2 obeys the Langmuir isotherm. Calculated quantum chemical parameters for studies inhibitors in gas and aqueous were further performed using density functional theory (DFT) at B3LYP/6-31G (d,p) to simulate the order of inhibitor’s performance on mild steel surface.

中文翻译：

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新型喹啉衍生物作为缓蚀剂在磷酸介质中吸附低碳钢的电化学和理论研究

摘要 两种新合成的喹啉衍生物5-((2-(4-二甲氨基)苯基-1H-苯并[d]咪唑-1-基)甲基)喹啉-8-醇(QN(CH3)2)和5-((2-(4-nitrophenyl)-1H-benzo[d]imidazol-1-yl)methyl)quinolin-8-ol (Q-NO2) 在低碳钢 (MS) 上的 2.0 M H3PO4 溶液已被评估通过重量损失 (WL​​)、Tafel 极化和电化学阻抗谱 (EIS)。实验结果表明，这些有机化合物在 2.0 M H3PO4 中作为良好的缓蚀剂发挥作用。抑制效率随着喹啉衍生物浓度的增加而增加。动电位极化研究表明，QN(CH3)2 和Q-NO2 是一种混合型抑制剂。EIS 研究表明电荷转移阻力随着抑制剂浓度的增加而增加，QN(CH3)2 和Q-NO2 的吸附服从Langmuir 等温线。使用密度泛函理论 (DFT) 在 B3LYP/6-31G (d,p) 下进一步计算气体和水中抑制剂的量子化学参数，以模拟抑制剂在低碳钢表面上的性能顺序。