Xu Hong-Lei, Popov Ivan A, Tkachenko Nikolay V, Wang Zi-Chuan, Muñoz-Castro Alvaro, Boldyrev Alexander I, Sun Zhong-Ming
Tianjin Key Lab of Rare Earth Materials and Applications, State Key Laboratory of Elemento-Organic Chemistry, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China.
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
Angew Chem Int Ed Engl. 2020 Sep 21;59(39):17286-17290. doi: 10.1002/anie.202008276. Epub 2020 Aug 13.
In this work, the largest heterometallic supertetrahedral clusters, [Zn Ge ] and [Cd Ge ] , were directly self-assembled through highly-charged [Ge ] units and transition metal cations, in which 3-center-2-electron σ bonding in Ge Zn or Ge Cd triangles plays a vital role in the stabilization of the whole structure. The cluster structures have an open framework with a large central cavity of diameter 4.6 Å for Zn and 5.0 Å for Cd, respectively. Time-dependent HRESI-MS spectra show that the larger clusters grow from smaller components with a single [Ge ] and ZnMes units. Calculations performed at the DFT level indicate a very large HOMO-LUMO energy gap in [M Ge ] (2.22 eV), suggesting high kinetic stability that may offer opportunities in materials science. These observations offer a new strategy for the assembly of heterometallic clusters with high symmetry.
在这项工作中，最大的异金属超四面体簇合物[Zn₄Ge₄]和[Cd₄Ge₄]，通过高电荷的[Ge₄]单元和过渡金属阳离子直接自组装而成，其中Ge₃Zn或Ge₃Cd三角形中的3中心2电子σ键在整个结构的稳定中起着至关重要的作用。这些簇合物结构具有开放框架，分别为含锌簇合物和含镉簇合物提供了直径为4.6 Å和5.0 Å的大中心腔。时间分辨高分辨电喷雾电离质谱（HRESI-MS）光谱表明，较大的簇合物由具有单个[Ge₄]和ZnMes单元的较小组分生长而来。在密度泛函理论（DFT）水平上进行的计算表明，[M₄Ge₄]（M = Zn，Cd）具有非常大的最高占据分子轨道（HOMO）-最低未占据分子轨道（LUMO）能隙（2.22 eV），表明其具有较高的动力学稳定性，这可能为材料科学提供机会。这些观察结果为组装具有高对称性的异金属簇合物提供了一种新策略。
