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Isolable dicarbon stabilized by a single phosphine ligand

Nature Chemistry volume 13, pages 89–93 (2021)Cite this article

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Abstract

In contrast to naturally occurring F2, O2 and N2, diatomic C2 is an intriguing species that has only been observed indirectly in the gas phase, and because of its high reactivity has eluded isolation in the condensed phase. It has previously been stabilized in L→C2←L compounds but the bonding situation of the central C2 in this motif differs remarkably from that of free C2. Here we have prepared and structurally characterized diatomic C2 as a monoligated complex L→C2 using a bulky phosphine ligand bearing two imidazolidin-2-iminato groups (L is (NHCR=N)2(CH3)P, where NHCR is an N-heterocyclic carbene). The compound is stable in solution at ambient temperature and has also been isolated in the solid state. Reactivity studies, in combination with quantum chemical analysis, suggest that the two carbon atoms of the L→C2 complex both have carbene character. The complex underwent intermolecular C–H bond activation upon thermolysis and exhibited hydroalkoxylation-like reactivity with methanol.

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Fig. 1: C2 chemistry.
Fig. 2: Single-crystal X-ray diffraction experiment for structural elucidation.
Fig. 3: Theoretical analysis of the electronic structure of 3.
Fig. 4: Reactivity studies of 3.
Fig. 5: Computational calculation on the thermolysis reaction pathway of dicarbon 3.

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Data availability

Crystallographic data for the structures in this paper have been deposited at the Cambridge Crystallographic Data Centre under reference numbers 1993538 (2), 1993539 (6), 1993540 (4), 1993541 (3) and 1993542 (5). Copies of the data can be obtained free of charge from www.ccdc.cam.ac.uk/structures/. All other data supporting the findings of this study are available within the article and its Supplementary Information, or from the corresponding authors upon reasonable request.

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Acknowledgements

This research was supported in part by the Ministry of Science & Technology of Taiwan (108-2113-M-001-026-MY3), an Academia Sinica Investigator Award Grant (AS-IA-108-M04), the National Natural Science Foundation of China (grant numbers 21703099, 21973044 and 21828101), the Natural Science Foundation of Jiangsu Province for Youth (grant number BK20170964) and Nanjing Tech University (grant numbers 39837123 and 39837132). We are grateful to the High-Performance Computing Center of Nanjing Tech University for supporting the computational resources. T.Y. acknowledges financial support from the Alexander von Humboldt foundation. Further support came from the Deutsche Forschungsgemeinschaft.

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Author notes

  1. These authors contributed equally: T.-F. Leung, D. Jiang, M.-C. Wu.

Authors and Affiliations

  1. Institute of Chemistry, Academia Sinica, Taipei, Taiwan, ROC

    Tsz-Fai Leung, Ming-Chun Wu, Wei-Min Ching & Tiow-Gan Ong

  2. Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, China

    Dandan Jiang, Dengmengfei Xiao, Lili Zhao & Gernot Frenking

  3. Department of Chemistry, National Taiwan University, Taipei, Taiwan, ROC

    Ming-Chun Wu & Tiow-Gan Ong

  4. Department of Chemistry, National Kaohsiung Normal University, Kaohsiung, Taiwan, ROC

    Wei-Min Ching

  5. Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA

    Glenn P. A. Yap

  6. School of Science, MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, Xi’an Jiaotong University, Xi’an, China

    Tao Yang

  7. Fachbereich Chemie, Philipps-Universität Marburg, Marburg, Germany

    Tao Yang & Gernot Frenking

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  1. Tsz-Fai Leung
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Contributions

T.-F.L. conceived the study. T.-F.L. and M.-C.W. performed and studied experiments. W.-M.C. assisted with the infrared measurements. D.J., D.X. and T.Y. carried out computational calculations. G.P.A.Y. did the crystallographic work. T.-F.L., D.J. and M.-C.W. contributed equally to the work and all authors contributed to data analysis. T.-G.O, L.Z. and G.F. supervised research and acquired funding. T.-F.L. and T.-G.O. wrote the original draft, which was reviewed and edited with input from all authors.

Corresponding authors

Correspondence to Lili Zhao, Tiow-Gan Ong or Gernot Frenking.

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Leung, TF., Jiang, D., Wu, MC. et al. Isolable dicarbon stabilized by a single phosphine ligand. Nat. Chem. 13, 89–93 (2021). https://doi.org/10.1038/s41557-020-00579-w

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