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Carboalumination of a chromium–chromium quintuple bond


Bonds are at the very heart of chemistry. Although the order of carbon–carbon bonds only extends to triple bonds, metal–metal bond orders of up to five are known for stable compounds, particularly between chromium atoms. Carbometallation and especially carboalumination reactions of carbon–carbon double and triple bonds are a well established synthetic protocol in organometallic chemistry and organic synthesis. We now extend these reactions to compounds containing chromium–chromium quintuple bonds. Analogous reactivity patterns indicate that such quintuple bonds are not as exotic as previously assumed. Yet the particularities of these reactions reflect the specific nature of the high metal–metal bond orders.

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Figure 1: Synthesis of 3, 4 and 5.
Figure 2: Molecular structure of 3.
Figure 3: Molecular structure of 4.
Figure 4: Molecular structure and electron localization function (ELF) isosurface of 5.


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We thank C. Döring for his support in the X-ray lab.

Author information




A.N. carried out the synthesis experiments and analysed the spectroscopic data. G.G. performed the X-ray single crystal structure analyses. R.M. and M.K. carried out the computational studies. S.D. performed the magnetic susceptibility experiments. R.K. originated the central idea and wrote the manuscript with contributions from all the co-authors.

Corresponding authors

Correspondence to Martin Kaupp or Rhett Kempe.

Supplementary information

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Supplementary information (PDF 833 kb)

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Crystallographic information for compound 2 (CIF 15 kb)

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Crystallographic information for compound 3 (CIF 15 kb)

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Crystallographic information for compound 4 (CIF 14 kb)

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Crystallographic information for compound 5 (CIF 32 kb)

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Noor, A., Glatz, G., Müller, R. et al. Carboalumination of a chromium–chromium quintuple bond. Nature Chem 1, 322–325 (2009).

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