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Synthesis and reactivity of copper carbyne anion complexes


Carbyne anions (R–C) are one of the least explored and most poorly understood subvalent carbon species and, so far, have only been observed in the gas phase. In this study, we report the synthesis and isolation of copper phosphinocarbyne anion complexes. The combination of a π-donor substituent and an electropositive transition metal enables the isolation of copper carbyne anion complexes at room temperature. The electronic structure of the isolated copper phosphinocarbyne anion complexes was probed using density functional theory calculations. These calculations reveal the dominance of ionic interactions between the copper and carbon atoms and the singlet ground state of the phosphinocarbyne anion, featuring a planar phosphorus atom and a short phosphorus–carbon bond. These complexes exhibit the reactivity of a carbyne anion, as demonstrated through the synthetic transformations to form silyl- and germanyl-substituted carbenes, diazaphospholidinyl-substituted alkenes and ethenimines.

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Fig. 1: Background and the main concept.
Fig. 2: Synthesis of copper carbyne anion complexes 5 and 6.
Fig. 3: Solid-state structures.
Fig. 4: Theoretical analysis.
Fig. 5: Reactivity of 5.
Fig. 6: Solid-state structures.
Fig. 7: Free energy profile for formation of 11.

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Data availability

General information, experimental procedures, 1H NMR/13C{1H} NMR/31P NMR/19F NMR spectra, X-ray crystallographic data, high resolution mass spectrometry data and infrared spectrometry data are provided in the Supplementary Information. For NMR spectra, see Supplementary Figs. 135. For selected NLMOs of HC≡C-CuIPent, P≡C-CuIPent, [H2C=C-CuIPent]+ and 6, see Supplementary Figs. 4043. For crystallographic analysis, see Supplementary Fig. 36 and Supplementary Tables 211. For natural bond orbital analysis of 6 and C, see Supplementary Table 13. For the mechanism leading to 11, see Supplementary Table 14. Crystallographic data for the structures reported in this article have been deposited at the Cambridge Crystallographic Data Centre, under deposition numbers CCDC 2169399 (2), 2169400 (3), 2169401 (4), 2169402 (5), 2169403 (6), 2169404 (7), 2169405 (8), 2210613 (9), 2169406 (11) and 2210612 (12). Copies of the data can be obtained free of charge via


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We acknowledge financial support from the National Natural Science Foundation of China (grant nos. 22271132 and 22101114), Shenzhen Science and Technology Innovation Programme (grant no. JCYJ20220530114806015), Guangdong Innovative & Entrepreneurial Research Team Programme (grant no. 2021ZT09C278), Guangdong Basic and Applied Basic Research Foundation (grant no. 2022A1515011717) and Guangdong Provincial Key Laboratory of Catalysis (grant no. 2020B121201002). The theoretical work was supported by the Center for Computational Science and Engineering and the CHEM High-Performance Supercomputer Cluster at SUSTech. We acknowledge the assistance of SUSTech Core Research Facilities. We thank D. A. Ruiz at SUSTech for polishing this paper.

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Authors and Affiliations



L.L.L. conceptualized and supervised the project. R.W. and X.F.W. performed the experimental work. L.L.L., R.W. and C.H performed the computational work. R.W. performed the X-ray crystallographic analyses. L.L.L. wrote the paper with the input from all authors. All authors discussed the results in detail and commented on the paper.

Corresponding author

Correspondence to Liu Leo Liu.

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The authors declare no competing interests.

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Peer review information

Nature Synthesis thanks Didier Bourissou and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Thomas West, in collaboration with the Nature Synthesis team.

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Supplementary information

Supplementary information

General information, experimental section, Supplementary Figs.1–43, Tables 1–14, computational details and references.

Supplementary Data 1

Crystallographic data for compound 2, CCDC: 2169399.

Supplementary Data 2

Crystallographic data for compound 3, CCDC: 2169400.

Supplementary Data 3

Crystallographic data for compound 4, CCDC: 2169401.

Supplementary Data 4

Crystallographic data for compound 5, CCDC: 2169402.

Supplementary Data 5

Crystallographic data for compound 6, CCDC: 2169403.

Supplementary Data 6

Crystallographic data for compound 7, CCDC: 2169404.

Supplementary Data 7

Crystallographic data for compound 8, CCDC: 2169405.

Supplementary Data 8

Crystallographic data for compound 9, CCDC: 2210613.

Supplementary Data 9

Crystallographic data for compound 11, CCDC: 2169406.

Supplementary Data 10

Crystallographic data for compound 12, CCDC: 2210612.

Supplementary Data 11

Cartesian coordinations of the optimized structures by DFT calculations.

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Wei, R., Wang, XF., Hu, C. et al. Synthesis and reactivity of copper carbyne anion complexes. Nat. Synth 2, 357–363 (2023).

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