Octacarbonyl Anion Complexes of the Late Lanthanides Ln(CO)8- (Ln=Tm, Yb, Lu) and the 32-Electron Rule
Octacarbonyl Anion Complexes of the Late Lanthanides Ln(CO)8- (Ln=Tm, Yb, Lu) and the 32-Electron Rule
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晚期镧系元素八羰基阴离子配合物Ln(CO)(8)(-) (Ln=Tm, Yb, Lu)和32电子规则
DOI：
10.1002/chem.201805260
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发表时间：
2019-03-01
影响因子：
4.3
通讯作者：
Zhou, Mingfei
中科院分区：
文献类型：
--
作者：
Jin, Jiaye;Pan, Sudip;Zhou, Mingfei
在气相中合成了镧系八羰基阴离子配合物Ln（CO）（8）（-）（Ln=Tm，Yb，Lu），并在羰基伸缩频率区用质量选择红外光解光谱进行了检测。通过比较CO伸缩振动频率的实验值和计算值，确定Yb（CO）（8）（-）和Lu（CO）（8）（-）配合物具有八面体（O-h）对称性和双重态X（2）A（2u）（Yb）和单重态X（1）A（1g）（Lu）电子基态，而Tm（CO）（8）（-）具有D-4 h平衡几何构型和三重态（XB 1g）-B-3基态。电子结构分析表明，金属-CO相互吸引力主要来自于共价轨道相互作用，主要是[Ln（d）]（CO）（8）的反馈作用和[Ln（d）]（CO）（8）的σ贡献作用（分别占共价键的77%和16%）.金属f轨道在成键中起很小的作用。所有三种镧系元素配合物的电子结构服从32电子规则，如果只考虑那些占据金属价轨道的电子。
The lanthanide octacarbonyl anion complexes Ln(CO)(8)(-) (Ln=Tm, Yb, Lu) were produced in the gas phase and detected by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching-frequency region. By comparison of the experimental CO-stretching frequencies with calculated data, which are strongly red-shifted with respect to free CO, the Yb(CO)(8)(-) and Lu(CO)(8)(-) complexes were determined to possess octahedral (O-h) symmetry and a doublet X(2)A(2u) (Yb) and singlet X(1)A(1g) (Lu) electronic ground state, whereas Tm(CO)(8)(-) exhibits a D-4h equilibrium geometry and a triplet (XB1g)-B-3 ground state. The analysis of the electronic structures revealed that the metal-CO attractive forces come mainly from covalent orbital interactions, which are dominated by [Ln(d)](CO)(8) backdonation and [Ln(d)](CO)(8) sigma donation (contributes approximate to 77 and 16% to covalent bonding, respectively). The metal f orbitals play a very minor role in the bonding. The electronic structure of all three lanthanide complexes obeys the 32-electron rule if only those electrons that occupy the valence orbitals of the metal are considered.