Electronic Structure of the Hieber Anion [Fe(Co)3(NO)]- Revisited by X-ray Emission and Absorption Spectroscopy
Electronic Structure of the Hieber Anion [Fe(Co)3(NO)]- Revisited by X-ray Emission and Absorption Spectroscopy
复制标题
DOI：
10.1021/acs.inorgchem.9b02092
复制
发表时间：
2020-03-16
影响因子：
4.6
通讯作者：
Bauer, Matthias
中科院分区：
文献类型：
--
作者：
Burkhardt, Lukas;Vukadinovic, Yannik;Bauer, Matthias
尽管Hieber阴离子[Fe(CO)(3)(NO)](-)近年来已被用作有机合成的活性催化剂，但关于中心Fe原子的氧化状态和NO配体的电荷仍存在争议。为了阐明这个问题并理解Hieber阴离子中的Fe-NO相互作用，我们用价核X射线发射光谱、X射线吸收近边结构光谱和高能分辨荧光检测XANES相结合的方法，研究了它与正式的3D(CO)S和形式的3D(CO)(4)(2-)的相互作用。为了提取有关电子结构的信息，采用含时密度泛函理论和基态密度泛函理论计算。这种实验和计算方法的结合表明，Hieber的Fe中心的电子密度与等电子的[Fe(CO)(4)](2-)的电子密度相似。这些观察结果挑战了最近对希伯阴离子的描述，并重新开启了关于实验和计算确定的铁的氧化态和NO配体上的电荷的辩论。
While the Hieber anion [Fe(CO)(3)(NO)](-) has been reincarnated in the last years as an active catalyst in organic synthesis, there is still a debate about the oxidation state of the central Fe atom and the resulting charge of the NO ligand. To shed new light on this question and to understand the Fe-NO interaction in the Hieber anion, it is investigated in comparison to the formal 3d(8) reference Fe(CO) s and the formal 3d(10) reference [Fe(CO)(4)](2-) by the combination of valence-to-core X-ray emission spectroscopy (VtC-XES), X-ray absorption near-edge structure spectroscopy (XANES), and high-energy-resolution fluorescence-detected XANES. In order to extract information about the electronic structure, time-dependent density functional theory and ground-state density functional theory calculations are applied. This combination of experimental and computational methods reveals that the electron density at the Fe center of the Hieber resembles that of the isoelectronic [Fe(CO)(4)](2-). These observations challenge recent descriptions of the Hieber anion and reopen the debate about the experimentally and computationally determined Fe oxidation state and charge on the NO ligand.