Awad Mohamed K, Halim W S Abdel, Atlam Faten M, Fawzy Mohamed M
Chemistry Department, Theoretical Applied Chemistry Unit (TACU), Faculty of Science, Tanta University, Tanta, Egypt.
Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
Sci Rep. 2025 Sep 17;15(1):32576. doi: 10.1038/s41598-025-19022-6.
The potential corrosion inhibition properties of pyrazolo-pyrimidine derivatives with extended π system for carbon steel in acidic medium were investigated through a combined DFT, Monte Carlo and molecular dynamic simulations to establish the relationship between electronic properties and adsorption behavior. Geometrical optimization, quantum chemical parameters, (FT-IR) and UV-Vis spectra were explored. The charge transfer and primary sites of adsorption corresponding to enhancement the corrosion inhibition were identified by NBO and Fukui analysis. The Pauli exchange repulsion effect was utilized for the examination of Localized Orbital Locator and Electron Localization Function. To identify bonding and anti-bonding interactions, a study of non-covalent interaction was conducted. Monte Carlo and molecular dynamic simulations predicted strong adsorption energies and explained the stability of inhibitor metal complexes. The ethyl ester substituted inhibitor showed the smallest energy gap (4.640 eV) and the highest negative adsorption energy (- 129.998 kcal·mol), indicating superior adsorption capability and inhibition efficiency. These findings offer theoretical framework for designing efficient corrosion inhibitors with extended π systems for carbon steel protection.
通过结合密度泛函理论（DFT）、蒙特卡罗模拟和分子动力学模拟，研究了具有扩展π体系的吡唑并嘧啶衍生物在酸性介质中对碳钢的潜在缓蚀性能，以建立电子性质与吸附行为之间的关系。研究了几何优化、量子化学参数、傅里叶变换红外光谱（FT-IR）和紫外可见光谱。通过自然键轨道（NBO）和福井分析确定了与缓蚀增强相对应的电荷转移和主要吸附位点。利用泡利交换排斥效应研究了定域轨道定位器和电子定域函数。为了识别键合和反键相互作用，进行了非共价相互作用的研究。蒙特卡罗模拟和分子动力学模拟预测了较强的吸附能，并解释了缓蚀剂金属配合物的稳定性。乙酯取代的缓蚀剂显示出最小的能隙（4.640电子伏特）和最高的负吸附能（-129.998千卡·摩尔），表明其具有优异的吸附能力和缓蚀效率。这些发现为设计具有扩展π体系的高效碳钢缓蚀剂提供了理论框架。
