Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Four-electron deoxygenative reductive coupling of carbon monoxide at a single metal site


Carbon dioxide is the ultimate source of the fossil fuels that are both central to modern life and problematic: their use increases atmospheric levels of greenhouse gases, and their availability is geopolitically constrained1. Using carbon dioxide as a feedstock to produce synthetic fuels might, in principle, alleviate these concerns. Although many homogeneous and heterogeneous catalysts convert carbon dioxide to carbon monoxide2, further deoxygenative coupling of carbon monoxide to generate useful multicarbon products is challenging3. Molybdenum and vanadium nitrogenases are capable of converting carbon monoxide into hydrocarbons under mild conditions, using discrete electron and proton sources4. Electrocatalytic reduction of carbon monoxide on copper catalysts5 also uses a combination of electrons and protons, while the industrial Fischer–Tropsch process uses dihydrogen as a combined source of electrons and electrophiles for carbon monoxide coupling at high temperatures and pressures6. However, these enzymatic and heterogeneous systems are difficult to probe mechanistically. Molecular catalysts have been studied extensively6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23 to investigate the elementary steps by which carbon monoxide is deoxygenated and coupled, but a single metal site that can efficiently induce the required scission of carbon–oxygen bonds and generate carbon–carbon bonds has not yet been documented. Here we describe a molybdenum compound, supported by a terphenyl–diphosphine ligand, that activates and cleaves the strong carbon–oxygen bond of carbon monoxide, enacts carbon–carbon coupling, and spontaneously dissociates the resulting fragment. This complex four-electron transformation is enabled by the terphenyl–diphosphine ligand24,25, which acts as an electron reservoir and exhibits the coordinative flexibility needed to stabilize the different intermediates involved in the overall reaction sequence. We anticipate that these design elements might help in the development of efficient catalysts for converting carbon monoxide to chemical fuels, and should prove useful in the broader context of performing complex multi-electron transformations at a single metal site.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Deoxygenative coupling of CO to produce a C2O1 fragment.
Figure 2: X-ray crystal structures of compounds 2, 3, 4 and 7.
Figure 3: NMR spectroscopic data.

Similar content being viewed by others

Accession codes

Data deposits

X-ray crystallographic coordinates for compounds 2, 3, 4 and 7 have been deposited at the Cambridge Crystallographic Database under accession numbers 1412068, 1412062, 1412063 and 1412064 respectively.


  1. Appel, A. M. et al. Frontiers, opportunities, and challenges in biochemical and chemical catalysis of CO2 fixation. Chem. Rev. 113, 6621–6658 (2013)

    Article  CAS  Google Scholar 

  2. Costentin, C., Robert, M. & Saveant, J.-M. Catalysis of the electrochemical reduction of carbon dioxide. Chem. Soc. Rev. 42, 2423–2436 (2013)

    Article  CAS  Google Scholar 

  3. Gattrell, M., Gupta, N. & Co, A. A review of the aqueous electrochemical reduction of CO2 to hydrocarbons at copper. J. Electroanal. Chem. 594, 1–19 (2006)

    Article  CAS  Google Scholar 

  4. Hu, Y. L., Lee, C. C. & Ribbe, M. W. Extending the carbon chain: hydrocarbon formation catalyzed by vanadium/molybdenum nitrogenases. Science 333, 753–755 (2011)

    Article  ADS  CAS  Google Scholar 

  5. Li, C. W., Ciston, J. & Kanan, M. W. Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper. Nature 508, 504–507 (2014)

    Article  ADS  CAS  Google Scholar 

  6. West, N. M., Miller, A. J. M., Labinger, J. A. & Bercaw, J. E. Homogeneous syngas conversion. Coord. Chem. Rev. 255, 881–898 (2011)

    Article  CAS  Google Scholar 

  7. Gardner, B. M. et al. Homologation and functionalization of carbon monoxide by a recyclable uranium complex. Proc. Natl Acad. Sci. USA 109, 9265–9270 (2012)

    Article  ADS  CAS  Google Scholar 

  8. Summerscales, O. T., Cloke, F. G. N., Hitchcock, P. B., Green, J. C. & Hazari, N. Reductive cyclotrimerization of carbon monoxide to the deltate dianion by an organometallic uranium complex. Science 311, 829–831 (2006)

    Article  ADS  CAS  Google Scholar 

  9. Miller, R. L., Wolczanski, P. T. & Rheingold, A. L. Carbide formation via carbon monoxide dissociation across a tungsten-tungsten triple bond. J. Am. Chem. Soc. 115, 10422–10423 (1993)

    Article  CAS  Google Scholar 

  10. LaPointe, R. E., Wolczanski, P. T. & Mitchell, J. F. Carbon monoxide cleavage by (silox)3Ta (silox = tert-Bu3SiO-). J. Am. Chem. Soc. 108, 6382–6384 (1986)

    Article  CAS  Google Scholar 

  11. Evans, W. J., Grate, J. W., Hughes, L. A., Zhang, H. & Atwood, J. L. Reductive homologation of carbon monoxide to a ketenecarboxylate by a low-valent organolanthanide complex: synthesis and x-ray crystal structure of [(C5Me5)4Sm2(O2CCCO)(THF)]2 . J. Am. Chem. Soc. 107, 3728–3730 (1985)

    Article  CAS  Google Scholar 

  12. Ballmann, J., Pick, F., Castro, L., Fryzuk, M. D. & Maron, L. Cleavage of carbon monoxide promoted by a dinuclear tantalum tetrahydride complex. Organometallics 31, 8516–8524 (2012)

    Article  CAS  Google Scholar 

  13. Watanabe, T., Ishida, Y., Matsuo, T. & Kawaguchi, H. Reductive coupling of six carbon monoxides by a ditantalum hydride complex. J. Am. Chem. Soc. 131, 3474–3475 (2009)

    Article  CAS  Google Scholar 

  14. Shima, T. & Hou, Z. Hydrogenation of carbon monoxide by tetranuclear rare earth metal polyhydrido complexes. Selective formation of ethylene and isolation of well-defined polyoxo rare earth metal clusters. J. Am. Chem. Soc. 128, 8124–8125 (2006)

    Article  CAS  Google Scholar 

  15. Matsuo, T. & Kawaguchi, H. A synthetic cycle for H2/CO activation and allene synthesis using recyclable zirconium complexes. J. Am. Chem. Soc. 127, 17198–17199 (2005)

    Article  CAS  Google Scholar 

  16. Belmonte, P. A., Cloke, F. G. N. & Schrock, R. R. Reduction of carbon monoxide by binuclear tantalum hydride complexes. J. Am. Chem. Soc. 105, 2643–2650 (1983)

    Article  CAS  Google Scholar 

  17. Carnahan, E. M., Protasiewicz, J. D. & Lippard, S. J. 15 years of reductive coupling—what have we learned? Acc. Chem. Res. 26, 90–97 (1993)

    Article  CAS  Google Scholar 

  18. Büchner, W. & Weiss, E. Zur kenntnis sogenannten alkalicarbonyle 4 uber reaktion von geschmolzenem kalium mit kohlenmonoxid. Helv. Chim. Acta 47, 1415–1423 (1964)

    Article  Google Scholar 

  19. Wayland, B. B., Sherry, A. E. & Coffin, V. L. Selective reductive coupling of carbon-monoxide. J. Chem. Soc. Chem. Commun. 662–663 (1989)

  20. Suess, D. L. M. & Peters, J. C. A CO-derived iron dicarbyne that releases olefin upon hydrogenation. J. Am. Chem. Soc. 135, 12580–12583 (2013)

    Article  CAS  Google Scholar 

  21. Peters, J. C., Odom, A. L. & Cummins, C. C. A terminal molybdenum carbide prepared by methylidyne deprotonation. Chem. Commun. 1995–1996 (1997)

  22. Kreissl, F. R., Frank, A., Schubert, U., Lindner, T. L. & Huttner, G. Carbonyl-η-cyclopentadienyl-(4-methylphenylketenyl)-bis(trimethylphosphane)tungsten—a novel, stable transition metal-substituted ketene. Angew. Chem. Int. Edn 15, 632–633 (1976)

    Article  Google Scholar 

  23. Churchill, M. R., Wasserman, H. J., Holmes, S. J. & Schrock, R. R. Coupling of methylidyne and carbonyl ligands on tungsten. Crystal structure of W(η2-HC≡COAlCl3)(CO)(PMe3)3Cl. Organometallics 1, 766–768 (1982)

    Article  CAS  Google Scholar 

  24. Buss, J. A., Edouard, G. A., Cheng, C., Shi, J. & Agapie, T. Molybdenum catalyzed ammonia borane dehydrogenation: oxidation state specific mechanisms. J. Am. Chem. Soc. 136, 11272–11275 (2014)

    Article  CAS  Google Scholar 

  25. Horak, K. T., Velian, A., Day, M. W. & Agapie, T. Arene non-innocence in dinuclear complexes of Fe, Co, and Ni supported by a para-terphenyl diphosphine. Chem. Commun. 50, 4427–4429 (2014)

    Article  CAS  Google Scholar 

  26. Cassani, M. C., Gun’ko, Y. K., Hitchcock, P. B., Lappert, M. F. & Laschi, F. Synthesis and characterization of organolanthanidocene(III) (Ln = La, Ce, Pr, Nd) complexes containing the 1,4-cyclohexa-2,5-dienyl ligand (benzene 1,4-dianion): structures of [K([18]-crown-6)][Ln{η5-C5H3(SiMe3)2-1,3}2(C6H6)] [Cp′′ = η5-C5H3(SiMe3)2-1,3; Ln = La, Ce, Nd]. Organometallics 18, 5539–5547 (1999)

    Article  CAS  Google Scholar 

  27. Ellis, J. E. Adventures with substances containing metals in negative oxidation states. Inorg. Chem. 45, 3167–3186 (2006)

    Article  CAS  Google Scholar 

  28. Enriquez, A. E., White, P. S. & Templeton, J. L. Reactions of an amphoteric terminal tungsten methylidyne complex. J. Am. Chem. Soc. 123, 4992–5002 (2001)

    Article  CAS  Google Scholar 

  29. Carlson, R. G. et al. The metathesis-facilitated synthesis of terminal ruthenium carbide complexes: a unique carbon atom transfer reaction. J. Am. Chem. Soc. 124, 1580–1581 (2002)

    Article  CAS  Google Scholar 

  30. Stewart, M. H., Johnson, M. J. A. & Kampf, J. W. Terminal carbido complexes of osmium: synthesis, structure, and reactivity comparison to the ruthenium analogues. Organometallics 26, 5102–5110 (2007)

    Article  CAS  Google Scholar 

Download references


We thank L. M. Henling and M. K. Takase for crystallographic assistance and D. VanderVelde for NMR expertise. We are grateful to Caltech and the National Science Foundation (grant CHE-1151918 to T.A., and GRFP to J.A.B.) for funding.

Author information

Authors and Affiliations



J.A.B. and T.A. designed the research. J.A.B. conducted the experiments. J.A.B. and T.A. interpreted the data and wrote the manuscript.

Corresponding author

Correspondence to Theodor Agapie.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information


This file contains Supplementary Text and Data, Supplementary Figures 1-28, Supplementary Tables 1-2, and additional references. Further information on the synthesis and characterization of the compounds and intermediates investigated in this study are detailed. (PDF 3812 kb)

This zipped file contains the crystallographic information files for complexes 2, 3, 4 & 7. (ZIP 6807 kb)

Supplementary Data 1

This file contains the Source Data for Supplementary Figure 21. (XLSX 161 kb)

Supplementary Data 2

This file contains the Source Data for Supplementary Figure 22. (XLSX 85 kb)

PowerPoint slides

Source data

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Buss, J., Agapie, T. Four-electron deoxygenative reductive coupling of carbon monoxide at a single metal site. Nature 529, 72–75 (2016).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing