Group II Metal Complexes of the Germylidendiide Dianion Radical and Germylidenide Anion |
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Authors: | Dr Siew‐Peng Chia Dr Emma Carter Dr Hong‐Wei Xi Dr Yongxin Li Dr Cheuk‐Wai So |
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Institution: | 1. Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore);2. School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT (UK);3. Division of Chemical and Biomolecular Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore) |
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Abstract: | The two‐electron reduction of a Group 14‐element(I) complex RË?] (E=Ge, R=supporting ligand) to form a novel low‐valent dianion radical with the composition RË:]. 2? is reported. The reaction of LGeCl] ( 1 , L=2,6‐(CH?NAr)2C6H3, Ar=2,6‐iPr2C6H3) with excess calcium in THF at room temperature afforded the germylidenediide dianion radical complex LGe]. 2??Ca(THF)32+ ( 2 ). The reaction proceeds through the formation of the germanium(I) radical LGe?], which then undergoes a two‐electron reduction with calcium to form 2 . EPR spectroscopy, X‐ray crystallography, and theoretical studies show that the germanium center in 2 has two lone pairs of electrons and the radical is delocalized over the germanium‐containing heterocycle. In contrast, the magnesium derivative of the germylidendiide dianion radical is unstable and undergoes dimerization with concurrent dearomatization to form the germylidenide anion complex C6H3‐2‐{C(H)?NAr}Ge‐Mg‐6‐{C(H)‐NAr}]2 ( 3 ). |
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Keywords: | anions calcium germanium Group 14 elements magnesium radicals |
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