In alignment with the principles of green chemistry as well as environmental sustainability, herein two novel double-armed corrosion inhibitors (CIs) 5,5′-((1,4-phenylenebis(azanylylidene))bis(methanylylidene))bis(2-methoxyphenol) (PAMM-1) and 6,6′-((1E,1′E)-(1,4-phenylenebis(azanylylidene))bis(methanylylidene))bis(2-methoxyphenol) (PAMM-2) were synthesized through energy-efficient ultrasound assisted synthetic pathway. Both of the CIs exhibited excellent corrosion inhibition properties toward the protection of mild steel (MS) in static HCl medium. Remarkably, the highest inhibition efficiency (IE) achieved through electrochemical analysis was 94.7% and 93.4% for 4 mM of PAMM-1 and PAMM-2, respectively. Morphological analysis has been evaluated through field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and water contact angle (WCA) measurements. The protective performance of CIs have been validated using density functional theory (DFT) and non covalent interaction (NCI) in a perceptive way. To delve deeper into the molecular level insights, the interactions of the CIs with corrosive elements and metal atoms in a real corrosive environment have been analyzed using molecular modelling, indicating spontaneous adsorption of the green CIs with high binding energy (947.37 kJ/mol). The present research is shedding light on how the IE is influenced by different positional substituents (–OCH and –OH) within the molecular scaffold, resulting in the ultimate achievement of ‘4E factors’: energy, economy, environment, and efficiency.

中文翻译：

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双臂亚苯基双(氮杂亚基)双(亚甲亚基)衍生物的节能合成与防腐行为深入解析：奏响4E协同的绿色国防交响曲


本着绿色化学和环境可持续性的原则，本文提出了两种新型双臂腐蚀抑制剂（CI）5,5'-((1,4-亚苯基双(氮杂亚基))双(亚甲基亚基))双(2-合成了 6,6′-((1E,1′E)-(1,4-亚苯基双(亚氮基))双(亚甲基))双(2-甲氧基苯酚)(PAMM-2)通过节能超声辅助合成途径。两种 CI 均表现出优异的缓蚀性能，可保护静态 HCl 介质中的低碳钢 (MS)。值得注意的是，通过电化学分析，4 mM PAMM-1 和 PAMM-2 的最高抑制效率 (IE) 分别为 94.7% 和 93.4%。通过场发射扫描电子显微镜 (FE-SEM)、原子力显微镜 (AFM)、X 射线光电子能谱 (XPS) 和水接触角 (WCA) 测量来评估形态分析。 CI 的保护性能已通过密度泛函理论 (DFT) 和非共价相互作用 (NCI) 以感知的方式得到验证。为了更深入地研究分子水平，我们使用分子模型分析了真实腐蚀环境中CI与腐蚀性元素和金属原子的相互作用，表明具有高结合能（947.37 kJ/mol）的绿色CI的自发吸附。目前的研究正在揭示分子支架内不同位置取代基（-OCH和-OH）如何影响IE，从而最终实现“4E因素”：能源、经济、环境和效率。