Abstract

Two imidazopyridine derivatives 6-chloro-2-(4-chlorophenyl) imidazo [1,2-a]pyridine (IPCl1) and 6-chloro-2-(4-chlorophenyl)imidazo[1,2-a]pyridine-3-carbal-dehyde (IPCl2) were investigated as corrosion inhibitors of mild steel in 1.0M HCl medium using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The concentrations used in this work ranged between 1.0 × 10^–6 and 1.0 × 10^–3 M. Those compounds were found to be good inhibitors. In addition, their adsorption on the mild steel surface obeyed the Langmuir adsorption isotherm. A quantum chemical calculation was computed using Gaussian 09 based on the density-functional theory method at B3LYP/6-31G (d, p) in order to relate some electronic properties of the studied compounds to the inhibition efficiencies achieved experimentally. The Fukui functions were calculated to estimate the most reactive sites of nucleophilic and electrophilic attacks. Finally, the molecular dynamics simulation was implemented to search for the equilibrium configurations of IPCl1 and IPCl2/Fe(110) adsorption systems in a hydrochloric acid solution at various temperatures. The theoretical and experimental results obtained were in good correlation.

中文翻译：

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咪唑并吡啶衍生物作为低碳钢在盐酸中的缓蚀剂的实验，密度泛函理论和动态分子研究

摘要

两种咪唑并吡啶衍生物6-氯-2-（4-氯苯基）咪唑并[1,2- a ]吡啶（IPCl1）和6-氯-2-（4-氯苯基）咪唑并[1,2-a]吡啶-3-使用电位动力学极化曲线和电化学阻抗谱研究了在1.0M HCl介质中作为低碳钢缓蚀剂的碳化钴（IPCl2）。在这项工作中使用的浓度范围为1.0×10 ^–6到1.0×10 ^–3M。发现这些化合物是好的抑制剂。另外，它们在低碳钢表面上的吸附遵循Langmuir吸附等温线。基于密度泛函理论方法在B3LYP / 6-31G（d，p），以便将研究化合物的某些电子性质与通过实验获得的抑制效率相关联。计算Fukui函数以估计亲核和亲电攻击的最活跃位点。最后，进行了分子动力学模拟，以寻找IPCl1和IPCl2 / Fe（110）吸附系统在盐酸溶液中不同温度下的平衡构型。获得的理论和实验结果具有良好的相关性。