Isolation of a Perfectly Linear Uranium(II) Metallocene
Isolation of a Perfectly Linear Uranium(II) Metallocene
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DOI：
10.1002/anie.201912663
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发表时间：
2020-01-03
影响因子：
16.6
通讯作者：
Layfield, Richard A.
中科院分区：
文献类型：
--
作者：
Guo, Fu-Sheng;Tsoureas, Nikolaos;Layfield, Richard A.
用钾石墨还原铀（III）茂金属[（eta（5）-（C5 Pr 5）-Pr 1）（2）UI]（1）产生“第二代”二茂铀[（eta（5）-（C5 Pr 5）-Pr 1）（2）U]（2），其含有形式二价氧化态的铀。2的几何构型是一个完全线性的双夹心配合物，电子光谱和密度泛函理论揭示了铀（II）的基态价电子构型为5 f（3）6d（1）。通过计算研究确定了对金属-配体键的可观的共价贡献，包括铀5 f和6d轨道的参与。而2中的三个未成对电子占据基本上纯5 f特征的轨道，第四个电子位于由强7s-6dz 2混合定义的轨道中。
Reduction of the uranium(III) metallocene [(eta(5)-(C5Pr5)-Pr-i)(2)UI] (1) with potassium graphite produces the "second-generation" uranocene [(eta(5)-(C5Pr5)-Pr-i)(2)U] (2), which contains uranium in the formal divalent oxidation state. The geometry of 2 is that of a perfectly linear bis(cyclopentadienyl) sandwich complex, with the ground-state valence electron configuration of uranium(II) revealed by electronic spectroscopy and density functional theory to be 5f(3) 6d(1). Appreciable covalent contributions to the metal-ligand bonds were determined from a computational study of 2, including participation from the uranium 5f and 6d orbitals. Whereas three unpaired electrons in 2 occupy orbitals with essentially pure 5f character, the fourth electron resides in an orbital defined by strong 7s-6dz2 mixing.