Comparative Study of the Electronic Structures of μ-Oxo, μ-Nitrido, and μ-Carbido Diiron Octapropylporphyrazine Complexes and Their Catalytic Activity in Cyclopropanation of Olefins
作者:Lucie P. Cailler、Martin Clémancey、Jessica Barilone、Pascale Maldivi、Jean-Marc Latour、Alexander B. Sorokin
DOI:10.1021/acs.inorgchem.9b02718
日期:2020.1.21
The electronic structure of three single-atom bridged diiron octapropylporphyrazine complexes (FePzPr8)2X having Fe(III)-O-Fe(III), Fe(III)-N-Fe(IV) and Fe(IV)-C-Fe(IV) structural units was investigated by Mössbauer spectroscopy and density functional theory (DFT) calculations. In this series, the isomer shift values decrease, whereas the values of quadrupole splitting become progressively greater
具有Fe(III)-O-Fe(III),Fe(III)-N-Fe(IV)和Fe(IV)-C-Fe( IV)通过Mössbauer光谱学和密度泛函理论(DFT)计算研究了结构单元。在该系列中,异构体位移值减小,而四极分裂值逐渐增大,表明在μ-氧代,μ-nitrido,μ-carbido行中Fe-X键的共价性增加。Mössbauer数据指向这三种配合物的低自旋系统,B3LYP-D3的计算数据显示了μ-氧代和μ-羰基的单重态,而μ-nitrido配合物的双峰态。在B3LYP-D3优化的几何形状与X射线结构数据之间获得了极好的协议。在(FePzPr8)2X络合物中,μ-氧代二铁物质在重氮乙酸乙酯对苯乙烯的环丙烷化反应中显示出更高的反应活性,以0.1摩尔%的催化剂负载量提供95%的产品收率。详尽的DFT研究使我们能够深入了解双核卡宾物种的电子结构,并确认它们参与了卡宾转移反应。