Oxidation of phenyl and hydride ligands of bis(pentamethylcyclopentadienyl)hafnium derivatives by nitrous oxide via selective oxygen atom transfer reactions: insights from quantum chemistry calculations.
Oxidation of phenyl and hydride ligands of bis(pentamethylcyclopentadienyl)hafnium derivatives by nitrous oxide via selective oxygen atom transfer reactions: insights from quantum chemistry calculations.
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DOI：
10.1039/c5dt03264d
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发表时间：
2016-01
影响因子：
4
通讯作者：
Hujun Xie;Chengcheng Liu;Ying Yuan;Tao Zhou;Ting Fan;Qun-fang Lei;Wenjun Fang
中科院分区：
文献类型：
--
作者：
Hujun Xie;Chengcheng Liu;Ying Yuan;Tao Zhou;Ting Fan;Qun-fang Lei;Wenjun Fang
采用密度泛函理论（DFT）计算方法，系统地研究了二（五甲基环戊二烯基）铪衍生物（Cp* = η(5)-C5Me5）的苯基和氢化物配体在选择性氧原子转移反应中被氧化的机理。在此基础上，我们对Hillhouse等人提出的N2O活化机理进行了研究。计算表明，N2O与配位不饱和Hf中心初始o配位的配合物不是局部最小值。然后，我们提出了一种新的反应机制来研究N2O是如何被激活的，以及N2O选择性氧化苯基和氢化物配体的原因。前沿分子轨道理论分析表明，N2O被苯基或氢化物配体的亲核攻击激活。目前的计算为N2O的活化提供了新的见解，涉及到从氧化亚氮到金属配体键的直接氧原子转移，而不是通常观察到的产生金属氧的吸氧反应。
The mechanisms for the oxidation of phenyl and hydride ligands of bis(pentamethylcyclopentadienyl)hafnium derivatives (Cp* = η(5)-C5Me5) by nitrous oxide via selective oxygen atom transfer reactions have been systematically studied by means of density functional theory (DFT) calculations. On the basis of the calculations, we investigated the original mechanism proposed by Hillhouse and co-workers for the activation of N2O. The calculations showed that the complex with an initial O-coordination of N2O to the coordinatively unsaturated Hf center is not a local minimum. Then we proposed a new reaction mechanism to investigate how N2O is activated and why N2O selectively oxidize phenyl and hydride ligands of . Frontier molecular orbital theory analysis indicates that N2O is activated by nucleophilic attack by the phenyl or hydride ligand. Present calculations provide new insights into the activation of N2O involving the direct oxygen atom transfer from nitrous oxide to metal-ligand bonds instead of the generally observed oxygen abstraction reaction to generate metal-oxo species.