轴向配体对铁卟啉催化氧化环己烷和苯C—H键的影响  

The Effect of Axial Ligands on the Catalytic Oxidation of Cyclohexane and Benzene C—H Bonds by Iron Porphyrins

作　　者：张玉静 宋旭锋[1] 马欣宇 于艳敏[1] ZHANG Yu-jing;SONG Xu-Feng;MA Xin-yu;YU Yan-min(Department of Chemical Engineering,Beijing Key Laboratory for Green Catalysis and Separation,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学化学工程与技术系绿色催化与分离北京市重点实验室,北京100124

出　　处：《化学试剂》2024年第5期47-52,共6页Chemical Reagents

基　　金：国家自然科学基金项目(21776021)。

摘　　要：采用密度泛函理论方法系统研究了带有不同轴向配体(F^(-)、Cl^(-)、CH_(3)COO^(-)、SCH^(-)_(3))的铁卟啉作为仿生催化剂催化氧化环己烷和苯C—H键的反应,重点考察了轴向配体对高价铁-氧卟啉几何结构和电子结构的影响,以及轴向配体影响高价铁-氧卟啉氧化环己烷和苯C—H键反应活性的本质差异。相较于其他轴向配体,F^(-)作为轴向配体使高价铁-氧卟啉具有更高的活性,更易于氧化环己烷和苯的C—H键。与苯环C—H键氧化反应相比,改变轴向配体对环己烷C—H键氧化反应的活性影响更大,且轴向配体主要通过影响过渡态结构中环己烷的形变能来改变环己烷C—H键氧化反应的活化能。而在苯环C—H键氧化反应中,轴向配体主要影响过渡态结构中高价铁-氧卟啉与苯的相互作用能以及苯分子的形变能。The present strudy focused on the systematic investigation of C—H bond oxidation in cyclohexane and benzene,catalyzed by iron porphyrins with various axial ligands(F^(-),Cl^(-),CH_(3)COO^(-),SCH^(-)_(3)),serving as biomimetic catalysts.Density functional theory was employed to examine the effect of axial ligands on the geometric and electronic structures of high-valent iron-oxygen porphyrin.Detailed analysis was performed to elucidate the inherent vatiations in reactivity caused by different axial ligands in the catalytic oxidation of cyclohexane and benzene C—H bonds by high-valent iron-oxygen porphyrin.Compared with other axial ligands,F^(-)exhibited enhanced reactivity,facilitating the C—H bond oxidation of cyclohexane and benzene.Moreover,it was observed that axial ligands had a more significant impact on the reactivity of cyclohexane C—H bond oxidation.The axial ligand primarily influenced the activation energy of the cyclohexane C—H bond oxidation reaction by altering the distortion energy of cyclohexane in the transition state.Conversely,in the benzene C—H bond oxidation reaction,the axial ligand simultaneously affected the interaction energy between the high-valent iron-oxygen porphyrin and benzene,as well as the distortion energy of benzene in the transition state.

关 键 词：铁卟啉 轴向配体 环己烷 苯 密度泛函理论 

分 类 号：O64[理学—物理化学]