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.

  • Article
  • Published:

One-pot, room-temperature conversion of dinitrogen to ammonium chloride at a main-group element


The industrial reduction of dinitrogen (N2) to ammonia is an energy-intensive process that consumes a considerable proportion of the global energy supply. As a consequence, species that can bind N2 and cleave its strong N–N bond under mild conditions have been sought for decades. Until recently, the only species known to support N2 fixation and functionalization were based on a handful of metals of the s and d blocks of the periodic table. Here we present one-pot binding, cleavage and reduction of N2 to ammonium by a main-group species. The reaction—a complex multiple reduction–protonation sequence—proceeds at room temperature in a single synthetic step through the use of solid-phase reductant and acid reagents. A simple acid quench of the mixture then provides ammonium, the protonated form of ammonia present in fertilizer. The elementary reaction steps in the process are elucidated, including the crucial N–N bond cleavage process, and all of the intermediates of the reaction are isolated.

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

Fig. 1: A one-pot, borylene-mediated synthesis of ammonium chloride from N2, and elucidation of the individual reduction–protonation steps involved.
Fig. 2: Schematic of the overall mechanism of the borylene-mediated ammonium synthesis.

Similar content being viewed by others

Data availability

Crystallographic data for the structures reported in this article have been deposited at the Cambridge Crystallographic Data Centre, under deposition numbers CCDC 1971191 (8), 1971192 (7), 1971193 (5) and 1971194 (6). Copies of the data can be obtained free of charge via Further data supporting the findings of this study are available from the corresponding author upon reasonable request.


  1. Notman, N. Haber–Bosch power consumption slashed. Chemistry World (21 October 2012).

  2. Allen, A. D., Senoff, C. V. Nitrogenopentammineruthenium(ii) complexes. J. Chem. Soc. D 621–622 (1965).

  3. Burford, R. J., Yeo, A. & Fryzuk, M. D. Dinitrogen activation by group 4 and group 5 metal complexes supported by phosphine-amido containing ligand manifolds. Coord. Chem. Rev. 334, 84–99 (2017).

    Article  CAS  Google Scholar 

  4. Tanaka, H., Nishibayashi, Y. & Yoshizawa, K. Interplay between theory and experiment for ammonia synthesis catalyzed by transition metal complexes. Acc. Chem. Res. 49, 987–995 (2016).

    Article  CAS  Google Scholar 

  5. Anderson, J. S., Rittle, J. & Peters, J. C. Catalytic conversion of nitrogen to ammonia by an iron model complex. Nature 501, 84–87 (2013).

    Article  CAS  Google Scholar 

  6. Fryzuk, M. D. N2 coordination. Chem. Commun. 49, 4866–4868 (2013).

    Article  CAS  Google Scholar 

  7. Hazari, N. Homogeneous iron complexes for the conversion of dinitrogen into ammonia and hydrazine. Chem. Soc. Rev. 39, 4044–4056 (2010).

    Article  CAS  Google Scholar 

  8. Schrock, R. R. Catalytic reduction of dinitrogen to ammonia at a single molybdenum center. Acc. Chem. Res. 38, 955–962 (2005).

    Article  CAS  Google Scholar 

  9. MacKay, B. A. & Fryzuk, M. D. Dinitrogen coordination chemistry: on the biomimetic borderlands. Chem. Rev. 104, 385–401 (2004).

    Article  CAS  Google Scholar 

  10. Hidai, M. & Mizobe, Y. Recent advances in the chemistry of dinitrogen complexes. Chem. Rev. 95, 1115–1133 (1995).

    Article  CAS  Google Scholar 

  11. Greenwood, N. N. & Earnshaw, A. Chemistry of the Elements 2nd edn (Elsevier Butterworth-Heinemann, 2005).

  12. Power, P. P. Main-group elements as transition metals. Nature 463, 171–177 (2010).

    Article  CAS  Google Scholar 

  13. Martin, D., Soleilhavoup, M. & Bertrand, G. Stable singlet carbenes as mimics for transition metal centers. Chem. Sci. 2, 389–399 (2011).

    Article  CAS  Google Scholar 

  14. Légaré, M.-A., Pranckevicius, C. & Braunschweig, H. Metallomimetic chemistry of boron. Chem. Rev. 119, 8231–8261 (2019).

    Article  Google Scholar 

  15. Kinjo, R., Donnadieu, B., Celik, M. A., Frenking, G. & Bertrand, G. Synthesis and characterization of a neutral tricoordinate organoboron isoelectronic with amines. Science 333, 610–613 (2011).

    Article  CAS  Google Scholar 

  16. Braunschweig, H. et al. Multiple complexation of CO and related ligands to a main-group element. Nature 522, 327–330 (2015).

    Article  CAS  Google Scholar 

  17. Soleilhavoup, M. & Bertrand, G. Borylenes: an emerging class of compounds. Angew. Chem. Int. Ed. 56, 10282–10292 (2017).

    Article  CAS  Google Scholar 

  18. Légaré, M.-A. et al. Nitrogen fixation and reduction at boron. Science 359, 896–900 (2018).

    Article  Google Scholar 

  19. Légaré, M.-A. et al. The reductive coupling of dinitrogen. Science 363, 1329–1332 (2019).

    Article  Google Scholar 

  20. Broere, D. L. J. & Holland, P. L. Boron compounds tackle dinitrogen. Science 359, 871 (2018).

    Article  CAS  Google Scholar 

  21. Liu, Y. et al. Facile ammonia synthesis from electrocatalytic N2 reduction under ambient conditions on N-doped porous carbon. ACS Catal. 8, 1186–1191 (2018).

    Article  CAS  Google Scholar 

  22. Qiu, W. et al. High-performance artificial nitrogen fixation at ambient conditions using a metal-free electrocatalyst. Nat. Commun. 9, 3485 (2018).

    Article  Google Scholar 

  23. Burford, R. J. & Fryzuk, M. D. Examining the relationship between coordination mode and reactivity of dinitrogen. Nat. Rev. Chem. 1, 0026 (2017).

    Article  CAS  Google Scholar 

  24. Chatt, J., Pearman, A. J. & Richards, R. L. The reduction of mono-coordinated molecular nitrogen to ammonia in a protic environment. Nature 253, 39–40 (1975).

    Article  CAS  Google Scholar 

  25. Pool., J. A., Lobkovsky, E. & Chirik, P. J. Hydrogenation and cleavage of dinitrogen to ammonia with a zirconium complex. Nature 427, 527–530 (2004).

    Article  CAS  Google Scholar 

  26. Laplaza, C. A. & Cummins, C. C. Dinitrogen cleavage by a three-coordinate molybdenum(iii) complex. Science 268, 861–863 (1995).

    Article  CAS  Google Scholar 

  27. Curley, J. J., Cook, T. R., Reece, S. Y., Müller, P. & Cummins, C. C. Shining light on dinitrogen cleavage: structural features, redox chemistry, and photochemistry of the key intermediate bridging dinitrogen complex. J. Am. Chem. Soc. 130, 9394–9405 (2008).

    Article  CAS  Google Scholar 

  28. Thompson, N. B., Green, M. T. & Peters, J. C. Nitrogen fixation via a terminal Fe(iv) nitride. J. Am. Chem. Soc. 139, 15312–15315 (2017).

    Article  CAS  Google Scholar 

  29. Hellman, A. et al. Predicting catalysis: understanding ammonia synthesis from first-principles calculations. J. Phys. Chem. B 110, 17719–17735 (2006).

    Article  CAS  Google Scholar 

  30. Rodriguez, M. M., Bill, E., Brennessel, W. W. & Holland, P. L. N2 reduction and hydrogenation to ammonia by a molecular iron–potassium complex. Science 334, 780–783 (2011).

    Article  CAS  Google Scholar 

  31. Bazhenova, T. A. & Shilov, A. E. Nitrogen fixation in solution. Coord. Chem. Rev. 144, 69–145 (1995).

    Article  CAS  Google Scholar 

  32. Doyle, L. R. et al. Catalytic dinitrogen reduction to ammonia at a triamidoamine–titanium complex. Angew. Chem. Int. Ed. 57, 6314–6318 (2018).

    Article  CAS  Google Scholar 

  33. Bezdek, M. J., Guo, S. & Chirik, P. J. Terpyridine molybdenum dinitrogen chemistry: synthesis of dinitrogen complexes that vary by five oxidation states. Inorg. Chem. 55, 3117–3127 (2016).

    Article  CAS  Google Scholar 

  34. Soleilhavoup, M. & Bertrand, G. Cyclic (alkyl)(amino)carbenes (CAACs): stable carbenes on the rise. Acc. Chem. Res. 48, 256–266 (2015).

    Article  CAS  Google Scholar 

  35. Bissinger, P. et al. Isolation of a neutral boron-containing radical stabilized by a cyclic (alkyl)(amino)carbene. Angew. Chem. Int. Ed. 53, 7360–7363 (2014).

    Article  CAS  Google Scholar 

  36. Braunschweig, H. et al. Main-group metallomimetics: transition metal-like photolytic CO substitution at boron. J. Am. Chem. Soc. 139, 1802–1805 (2017).

    Article  CAS  Google Scholar 

  37. Arrowsmith, M. et al. Direct access to a CAAC-supported dihydrodiborene and its dianion. Chem. Commun. 54, 4669–4672 (2018).

    Article  CAS  Google Scholar 

  38. Arrowsmith, M. et al. Facile synthesis of a stable dihydroboryl {BH2} anion. Angew. Chem. Int. Ed. 57, 15272–15275 (2018).

    Article  CAS  Google Scholar 

  39. Armarego, W. L. F. & Chai, C. L. L. Purification of Laboratory Chemicals 6th edn (Elsevier, 2009).

  40. Chaney, A. L. & Marbach, E. P. Modified reagents for determination of urea and ammonia. Clin. Chem. 8, 130–132 (1962).

    Article  CAS  Google Scholar 

  41. Stoll, S. & Schweiger, A. EasySpin, a comprehensive software package for spectral simulation and analysis in EPR. J. Magn. Reson. 178, 42–55 (2006).

    Article  CAS  Google Scholar 

  42. Sheldrick, G. SHELXT—integrated space-group and crystal-structure determination. Acta Crystallogr. A 71, 3–8 (2015).

    Article  Google Scholar 

  43. Sheldrick, G. A short history of SHELX. Acta Crystallogr. A 64, 112–122 (2008).

    Article  CAS  Google Scholar 

Download references


We thank the Deutsche Forschungsgemeinschaft for financial support. M.-A.L. thanks the Natural Sciences and Engineering Research Council of Canada for a postdoctoral fellowship. G.B.-C. thanks the Alexander von Humboldt Foundation for a postdoctoral fellowship.

Author information

Authors and Affiliations



Experiments were designed by M.-A.L., G.B.-C., R.D.D. and H.B. and performed by M.-A.L., M.R. and G.B.-C. Data analysis was performed by M.-A.L., G.B.-C. and the article was written by M.-A.L. and R.D.D. X-ray crystallography was performed by G.B.-C. The EPR investigation was performed by I.K. and the NMR experiments were performed by R.B. The project was overseen by H.B. All authors read and commented on the manuscript.

Corresponding author

Correspondence to Holger Braunschweig.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–30.

Supplementary Data 1

CIF file for compound 5.

Supplementary Data 2

CIF file for compound 6.

Supplementary Data 3

CIF file for compound 7.

Supplementary Data 4

CIF file for compound 8.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Légaré, MA., Bélanger-Chabot, G., Rang, M. et al. One-pot, room-temperature conversion of dinitrogen to ammonium chloride at a main-group element. Nat. Chem. 12, 1076–1080 (2020).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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