【摘要】 [目的]针对电镀Zn–Fe合金镀层耐蚀性提升的需求，通过量子化学计算研究四羟基己二酸、焦磷酸盐和羟基乙叉二膦酸（HEDP）3种常用配位剂与Fe²⁺的配位行为，揭示配位剂对电沉积过程及镀层性能的影响机制。[方法]采用密度泛函理论（DFT）及M06-2X泛函，在def2-SVP基组水平上优化3种铁配合物的几何构型；利用sobEDA方法定量分解配位键能量；通过HOMO-LUMO轨道分析计算能隙（ΔE）；结合IGMH（基于赫什菲尔德划分的独立梯度模型）和IRI（相互作用区域指示函数）方法可视化表征配合物内Fe─O之间的弱相互作用类型与强度。[结果]能量分解表明，3种配合物的配位键均以静电作用为主导，总相互作用能排序为：羟基乙叉二膦酸合铁<焦磷酸合铁<四羟基己二酸合铁，羟基乙叉二膦酸合铁的配位键最强。HOMO-LUMO分析显示焦磷酸合铁的能隙最大，表明其化学反应活性最低、动力学稳定性最高；四羟基己二酸合铁的能隙最小，反应活性最高。IGMH和IRI分析均表明，羟基乙叉二膦酸合铁中Fe─O间强吸引弱相互作用最强，但空间排斥作用也最显著。[结论]焦磷酸盐配合物兼具较高的稳定性和适中的配位强度，是调控Zn–Fe合金电沉积行为的优选配位剂。本研究可为Zn–Fe合金电镀配位剂的筛选及工艺参数优化提供理论依据。更多还原

【Abstract】 [Objective] To address the demand for improving the corrosion resistance of electroplated Zn–Fe alloy coatings, the coordination behaviors of three commonly used complexing agents, including tetrahydroxyadipic acid, pyrophosphate, and hydroxyethylidene diphosphonic acid（HEDP） with Fe²⁺ were investigated via quantum chemical calculations, aiming to reveal the influencing mechanism of complexing agents on the electrodeposition process and coating properties. [Method] The geometric configurations of the three iron complexes were optimized using density functional theory（DFT） with the M06-2X functional at the def2-SVP basis set level. The coordination bond energies were quantitatively decomposed by the sobEDA method. The HOMO-LUMO energy gaps（ΔE） were calculated via orbital analysis. The types and strengths of weak interactions（Fe─O） within the complexes were visualized by combining IGMH（independent gradient model based on Hirshfeld partition） and IRI（interaction region indicator） methods. [Result] Energy decomposition showed that the coordination bonds in the three complexes were dominated by electrostatic interactions, with the total interaction energy following the order: iron（Ⅱ） hydroxyethylidene diphosphonate complex < iron（Ⅱ） pyrophosphate complex < iron（Ⅱ） tetrahydroxyadipate complex, indicating that the iron（Ⅱ） hydroxyethylidene diphosphonate complex had the strongest coordination bonds. HOMO-LUMO analysis revealed that the iron（Ⅱ） pyrophosphate complex exhibited the highest energy gap, demonstrating the lowest chemical reactivity and highest kinetic stability, whereas the iron（Ⅱ） tetrahydroxyadipate complex had the lowest energy gap and thus the highest reactivity. Both IGMH and IRI analyses indicated that the iron（Ⅱ） hydroxyethylidene diphosphonate complex showed the strongest attractive weak interactions（Fe─O）, but also the most significant steric repulsion. [Conclusion] The pyrophosphate complex possesses relatively high stability and moderate coordination strength, making it a preferred complexing agent for regulating the electrodeposition behavior of Zn–Fe alloys. This study provides a theoretical basis for the selection of complexing agents and the optimization of process parameters in Zn–Fe alloy electroplating.更多还原