Abstract
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
Relevant articles
Open Access articles citing this article.
-
A step-for-step main-group replica of the Fischer carbene synthesis at a borylene carbonyl
Nature Communications Open Access 13 May 2023
-
Access to cationic polyhedral carboranes via dynamic cage surgery with N-heterocyclic carbenes
Nature Communications Open Access 17 August 2021
-
Towards the catalytic activation of inert small molecules by main-group ambiphiles
Communications Chemistry Open Access 16 September 2020
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Get just this article for as long as you need it
$39.95
Prices may be subject to local taxes which are calculated during checkout


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 https://www.ccdc.cam.ac.uk/structures/. Further data supporting the findings of this study are available from the corresponding author upon reasonable request.
References
Notman, N. Haber–Bosch power consumption slashed. Chemistry World (21 October 2012).
Allen, A. D., Senoff, C. V. Nitrogenopentammineruthenium(ii) complexes. J. Chem. Soc. D 621–622 (1965).
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).
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).
Anderson, J. S., Rittle, J. & Peters, J. C. Catalytic conversion of nitrogen to ammonia by an iron model complex. Nature 501, 84–87 (2013).
Fryzuk, M. D. N2 coordination. Chem. Commun. 49, 4866–4868 (2013).
Hazari, N. Homogeneous iron complexes for the conversion of dinitrogen into ammonia and hydrazine. Chem. Soc. Rev. 39, 4044–4056 (2010).
Schrock, R. R. Catalytic reduction of dinitrogen to ammonia at a single molybdenum center. Acc. Chem. Res. 38, 955–962 (2005).
MacKay, B. A. & Fryzuk, M. D. Dinitrogen coordination chemistry: on the biomimetic borderlands. Chem. Rev. 104, 385–401 (2004).
Hidai, M. & Mizobe, Y. Recent advances in the chemistry of dinitrogen complexes. Chem. Rev. 95, 1115–1133 (1995).
Greenwood, N. N. & Earnshaw, A. Chemistry of the Elements 2nd edn (Elsevier Butterworth-Heinemann, 2005).
Power, P. P. Main-group elements as transition metals. Nature 463, 171–177 (2010).
Martin, D., Soleilhavoup, M. & Bertrand, G. Stable singlet carbenes as mimics for transition metal centers. Chem. Sci. 2, 389–399 (2011).
Légaré, M.-A., Pranckevicius, C. & Braunschweig, H. Metallomimetic chemistry of boron. Chem. Rev. 119, 8231–8261 (2019).
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).
Braunschweig, H. et al. Multiple complexation of CO and related ligands to a main-group element. Nature 522, 327–330 (2015).
Soleilhavoup, M. & Bertrand, G. Borylenes: an emerging class of compounds. Angew. Chem. Int. Ed. 56, 10282–10292 (2017).
Légaré, M.-A. et al. Nitrogen fixation and reduction at boron. Science 359, 896–900 (2018).
Légaré, M.-A. et al. The reductive coupling of dinitrogen. Science 363, 1329–1332 (2019).
Broere, D. L. J. & Holland, P. L. Boron compounds tackle dinitrogen. Science 359, 871 (2018).
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).
Qiu, W. et al. High-performance artificial nitrogen fixation at ambient conditions using a metal-free electrocatalyst. Nat. Commun. 9, 3485 (2018).
Burford, R. J. & Fryzuk, M. D. Examining the relationship between coordination mode and reactivity of dinitrogen. Nat. Rev. Chem. 1, 0026 (2017).
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).
Pool., J. A., Lobkovsky, E. & Chirik, P. J. Hydrogenation and cleavage of dinitrogen to ammonia with a zirconium complex. Nature 427, 527–530 (2004).
Laplaza, C. A. & Cummins, C. C. Dinitrogen cleavage by a three-coordinate molybdenum(iii) complex. Science 268, 861–863 (1995).
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).
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).
Hellman, A. et al. Predicting catalysis: understanding ammonia synthesis from first-principles calculations. J. Phys. Chem. B 110, 17719–17735 (2006).
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).
Bazhenova, T. A. & Shilov, A. E. Nitrogen fixation in solution. Coord. Chem. Rev. 144, 69–145 (1995).
Doyle, L. R. et al. Catalytic dinitrogen reduction to ammonia at a triamidoamine–titanium complex. Angew. Chem. Int. Ed. 57, 6314–6318 (2018).
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).
Soleilhavoup, M. & Bertrand, G. Cyclic (alkyl)(amino)carbenes (CAACs): stable carbenes on the rise. Acc. Chem. Res. 48, 256–266 (2015).
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).
Braunschweig, H. et al. Main-group metallomimetics: transition metal-like photolytic CO substitution at boron. J. Am. Chem. Soc. 139, 1802–1805 (2017).
Arrowsmith, M. et al. Direct access to a CAAC-supported dihydrodiborene and its dianion. Chem. Commun. 54, 4669–4672 (2018).
Arrowsmith, M. et al. Facile synthesis of a stable dihydroboryl {BH2}− anion. Angew. Chem. Int. Ed. 57, 15272–15275 (2018).
Armarego, W. L. F. & Chai, C. L. L. Purification of Laboratory Chemicals 6th edn (Elsevier, 2009).
Chaney, A. L. & Marbach, E. P. Modified reagents for determination of urea and ammonia. Clin. Chem. 8, 130–132 (1962).
Stoll, S. & Schweiger, A. EasySpin, a comprehensive software package for spectral simulation and analysis in EPR. J. Magn. Reson. 178, 42–55 (2006).
Sheldrick, G. SHELXT—integrated space-group and crystal-structure determination. Acta Crystallogr. A 71, 3–8 (2015).
Sheldrick, G. A short history of SHELX. Acta Crystallogr. A 64, 112–122 (2008).
Acknowledgements
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
Contributions
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
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
About this article
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). https://doi.org/10.1038/s41557-020-0520-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41557-020-0520-6
This article is cited by
-
A step-for-step main-group replica of the Fischer carbene synthesis at a borylene carbonyl
Nature Communications (2023)
-
Recent advances in the chemistry and applications of N-heterocyclic carbenes
Nature Reviews Chemistry (2021)
-
Access to cationic polyhedral carboranes via dynamic cage surgery with N-heterocyclic carbenes
Nature Communications (2021)
-
Towards the catalytic activation of inert small molecules by main-group ambiphiles
Communications Chemistry (2020)