Abstract
Vinylidene (H2C=C) is a member of the family of compounds of composition CH (and isomeric with ethyne, HC≡CH), but it has been observed only transiently—with a lifetime in the region of 0.1 ns. Indeed, no simple (non-base-stabilized) compounds of the type R2E=E have been characterized structurally for any of the group 14 elements. Here we show that by employing the bulky and strongly electron-donating boryl ligand (HCDippN)2B (Dipp, 2,6-iPr2C6H3), a simple monomeric digermavinylidene compound, (boryl)2GeGe, can be synthesized and is stable at room temperature. Both its formation via the two-electron chemical oxidation of the symmetrical Ge0 compound K2[(boryl)GeGe(boryl)] and its subsequent reaction chemistry (for example, with H2), are consistent with a high substituent lability and the accessibility of both 1,1- and 1,2-substitution patterns. Structural and computational studies of [(HCDippN)2B]2GeGe reveal a weak Ge–Ge double bond—the π component of which contributes to the highest occupied molecular orbital (HOMO)—with a Ge-centred lone pair as the HOMO–1.
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A sandwich-type cluster containing Ge@Pd3 planar fragment flanked by aromatic nonagermanide caps
Nature Communications Open Access 20 October 2020
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Acknowledgements
This work was supported by the Marie Curie Intra-European Fellowships programme of the European Union (PIEF-GA-2013-622806) and the Engineering and Physical Sciences Research Council (EP/L025000/1).
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A.R. synthesized and characterized the compounds. A.R. and J.C. collected the single-crystal X-ray crystallographic data and solved the crystal structures. A.R. and H.N. carried out the DFT calculations. S.A. generated and managed the project and wrote the manuscript. All the authors discussed the results and commented on the manuscript.
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Crystallographic data for compound 1 (CIF 34 kb)
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Structure factors file for compound 1 (FCF 547 kb)
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Crystallographic data for compound 2 (CIF 8685 kb)
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Crystallographic data for compound 3.1/2(C7H8) (CIF 1658 kb)
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Crystallographic data for compound 4 (CIF 1630 kb)
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Crystallographic data for compound 5 (CIF 1137 kb)
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Crystallographic data for compound 6 (CIF 643 kb)
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Rit, A., Campos, J., Niu, H. et al. A stable heavier group 14 analogue of vinylidene. Nature Chem 8, 1022–1026 (2016). https://doi.org/10.1038/nchem.2597
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DOI: https://doi.org/10.1038/nchem.2597
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