σ‐Aromaticity‐Induced Stabilization of Heterometallic Supertetrahedral Clusters [Zn6Ge16]4− and [Cd6Ge16]4− |
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Authors: | Hong‐Lei Xu Ivan A Popov Nikolay V Tkachenko Zi‐Chuan Wang Alvaro Muoz‐Castro Alexander I Boldyrev Zhong‐Ming Sun |
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Institution: | Hong‐Lei Xu,Ivan A. Popov,Nikolay V. Tkachenko,Zi‐Chuan Wang,Alvaro Muñoz‐Castro,Alexander I. Boldyrev,Zhong‐Ming Sun |
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Abstract: | In this work, the largest heterometallic supertetrahedral clusters, Zn6Ge16]4? and Cd6Ge16]4?, were directly self‐assembled through highly‐charged Ge4]4? units and transition metal cations, in which 3‐center–2‐electron σ bonding in Ge2Zn or Ge2Cd 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 Ge4]4? and ZnMes2 units. Calculations performed at the DFT level indicate a very large HOMO–LUMO energy gap in M6Ge16]4? (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. |
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Keywords: | planar tetracoordinate Zn/Cd supertetrahedron Td symmetry Zintl clusters σ -aromaticity |
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