Abstract The corrosion inhibition of API 5 L X52 in 1 M HCl due to fluconazole as active substance 1 or drug (Afungil), and its fragments: 1,2,4-triazole 2 and 1-bromo-2,4-difluorobenzene 3 was evaluated through electrochemical techniques and DFT calculations. At 20 °C, 1 exhibited c.a. 90 % corrosion inhibition efficiency, IE, from 5 to 200 ppm. The fragment 2 displayed an IE of 83% at 30 ppm, while the fragment 3 reached 80% at all concentrations. However, the inhibition kinetics study of 1 demonstrated that it retained its IE properties up to 168 hours of immersion with 84% IE. 1 followed a Langmuir-type physisorption-chemisorption process while 2 and 3 a physisorption process. From SEM and AFM images it was directly verified the steel-protective capacity of 1 and from XPS analysis its presence onto the steel surfaces. Theoretical calculations, carried out at the dispersion corrected density functional theory BPW91-D2/6-311++G(2d,2p) level, are in full agreement with experimental observations, explaining that the physisorption-chemisorption process was provoked by the electrostatic interaction and electron pairs donation of fluconazole on the iron atoms. Similarly, the adsorption process of protonated fluconazole is due to electrostatic interactions and electrons shared from the metal cluster to the protonates species. Reactivity indices indicate that the steel surface is effectively covered and passivated.

中文翻译：

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作为 API 5L X52 钢浸入 1M HCl 的缓蚀剂的氟康唑和碎片

摘要 由于氟康唑作为活性物质 1 或药物 (Afungil) 及其片段：1,2,4-三唑 2 和 1-溴-2,4-二氟苯 3，API 5 L X52 在 1 M HCl 中的缓蚀作用为通过电化学技术和 DFT 计算进行评估。在 20 °C 下，1 表现出大约 90% 的腐蚀抑制效率，IE，从 5 到 200 ppm。片段 2 在 30 ppm 时的 IE 为 83%，而片段 3 在所有浓度下均达到 80%。然而，1 的抑制动力学研究表明，它在 84% IE 下浸泡 168 小时后仍保持其 IE 特性。1遵循Langmuir型物理吸附-化学吸附过程，而2和3遵循物理吸附过程。从 SEM 和 AFM 图像直接验证了 1 的钢保护能力，并从 XPS 分析它在钢表面上的存在。理论计算，在色散校正密度泛函理论BPW91-D2/6-311++G(2d,2p)水平上进行的，与实验观察完全一致，说明物理吸附-化学吸附过程是由静电相互作用和电子对引起的氟康唑对铁原子的捐赠。类似地，质子化氟康唑的吸附过程是由于静电相互作用和从金属簇到质子酸盐物质共享的电子。反应性指数表明钢表面被有效地覆盖和钝化。解释物理吸附 - 化学吸附过程是由氟康唑在铁原子上的静电相互作用和电子对捐赠引起的。类似地，质子化氟康唑的吸附过程是由于静电相互作用和从金属簇到质子酸盐物质共享的电子。反应性指数表明钢表面被有效地覆盖和钝化。解释物理吸附 - 化学吸附过程是由氟康唑在铁原子上的静电相互作用和电子对捐赠引起的。类似地，质子化氟康唑的吸附过程是由于静电相互作用和从金属簇到质子酸盐物质共享的电子。反应性指数表明钢表面被有效地覆盖和钝化。