Department of Chemistry, Brown University, Providence, RI, 02912, USA.
Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Tsinghua University, Beijing, 100084, China.
Angew Chem Int Ed Engl. 2017 Jun 6;56(24):6916-6920. doi: 10.1002/anie.201703111. Epub 2017 May 8.
The structure and bonding of a Pr-doped boron cluster (PrB ) are investigated using photoelectron spectroscopy and quantum chemistry. The adiabatic electron detachment energy of PrB is found to be low [1.47(8) eV]. A large energy gap is observed between the first and second detachment features, indicating a highly stable neutral PrB . Global minimum searches and comparison between experiment and theory show that PrB has a half-sandwich structure with C symmetry. Chemical bonding analyses show that PrB can be viewed as a Pr [η -B ] complex with three unpaired electrons, corresponding to a Pr (4f 6s ) open-shell configuration. Upon detachment of the 6s electron, the neutral PrB cluster is a highly stable Pr [η -B ] complex with Pr in its favorite +3 oxidation state. The B ligand is found to be highly stable and doubly aromatic with six delocalized π and six delocalized σ electrons and should exist for a series of lanthanide M [η -B ] complexes.
采用光电子能谱和量子化学方法研究了掺镨硼团簇（PrB）的结构和键合。发现 PrB 的绝热电子离解能较低[1.47（8）eV]。首次和第二次离解特征之间观察到较大的能隙，表明中性 PrB 非常稳定。全局最小搜索和实验与理论的比较表明，PrB 具有 C 对称的半三明治结构。成键分析表明，PrB 可以看作是具有三个未配对电子的 Pr[η-B]配合物，对应于 Pr（4f6s）开壳层构型。在 6s 电子脱离后，中性 PrB 团簇是一个非常稳定的 Pr[η-B]配合物，其中 Pr 处于其首选的+3 氧化态。发现 B 配体高度稳定，具有双重芳香性，具有六个离域的π和六个离域的σ电子，并且应该存在于一系列镧系元素 M[η-B]配合物中。
