论文题目：A sandwich-type cluster containing Ge@Pd3 planar fragment flanked by aromatic nonagermanide caps
论文作者：Honglei Xu, Nikolay V. Tkachenko, Zichuan Wang, Weixing Chen, Lei Qiao, Alvaro Muñoz-Castro, Alexander I.Boldyrev, Zhongming Sun*
Abstract：
Sandwich-type clusters with the planar fragment containing a heterometallic sheet have remained elusive. In this work, we introduce the [K(2,2,2-crypt)](4){(Ge-9)(2)[eta (6)-Ge(PdPPh3)(3)]} complex that contains a heterometallic sandwich fragment. The title compound is structurally characterized by means of single-crystal X-ray diffraction, which reveals the presence of an unusual heteroatomic metal planar fragment Ge@Pd-3. The planar fragment contains a rare formal zerovalent germanium core and a peculiar bonding mode of sp(2)-Ge@(PdPPh3)(3) trigonal planar structure, whereas the nonagermanide fragments act as capping ligands. The chemical bonding pattern of the planar fragment consists of three 2c-2e Pd-Ge sigma -bonds attaching Pd atoms to the core Ge atom, while the binding between the planar fragment and the aromatic Ge-9 ligands is provided by six 2c-2e Pd-Ge sigma -bonds and two delocalized 4c-2e sigma -bonds. The synthesized cluster represents a rare example of a sandwich compound with the heteroatomic metal planar fragment and inorganic aromatic capping ligands. Sandwich-type clusters containing heterometallic interlayers have remained elusive. Here, the authors present the structure of a cluster composed of two aromatic nonagermanide caps flanking an heterometallic Ge@Pd-3 planar fragment, where the Ge center is formally zerovalent.