Abstract by Prof. Dr. Sven Schneider, Georg-August-Universität Göttingen

The Fixation with Fixation: Chemical Transformations of Dinitrogen

The fixation of dinitrogen to ammonia provides the nitrogen feedstock for the nutrition of about half of the earth's population and for the production of basically all synthetic N-containing chemicals. The Haber-Bosch process that operates at about 200 million tons pa is highly energy intensive, consuming about 1?2% of the global energy demand. For these reasons, N ₂ fixation at ambient conditions, which is accomplished in nature by the nitrogenase enzymes, is a highly attractive, yet still challenging task for homogeneous catalysis.

In recent years, our group examined elementary reactions relevant to such N ₂ -fixation strategies, such as nitride hydrogenolysis and coupling, [1,2] thermal and electrochemical N ₂ splitting into molecular nitrides, [3] or the direct conversion of N ₂ to organic molecules (Figure), [4] using transition metal pincer complexes. In this context, mechanistic aspects of key reactions and electronic structure / reactivity relationships for pivotal intermediates will be discussed.

[1] (a) B. Askevold, JT Nieto, S. Tussupbayev, M. Diefenbach, E. Herdtweck, MC Holthausen, S. Schneider, Nature Chem. 2011, 3, 532. (b) FS Schendzielorz, M. Finger , C. Volkmann, C. Würtele, S. Schneider, Angew. Chem. Int. Ed. 2016, 55, 11417.
[2] (a) MG Scheibel, B. Askevold, E. Reijerse, F. Heinemann, B. de Bruin, S. Schneider, Nature Chem. 2012, 4, 552. (b) MG Scheibel, Y. Wu, AC Stückl, L. Krause, E. Carl, D. Stalke, B. de Bruin, S. Schneider, J. Am. Chem. Soc. 2013, 135, 17719.
[3] (a) I. Klopsch, M. Finger, C. Würtele, B. Milde, DB Werz, S. Schneider, J. Am. Chem. Soc. 2014, 136, 6881. (b) GA Silantyev, M. Förster, B. Schluschaß, J. Abbenseth, C. Würtele, C. Volkmann, MC Holthausen, S. Schneider, Angew. Chem. Int. Ed. 2017, 56, 5872. (c) BM Lindley, RS van Alten, M. Finger, F. Schendzielorz, C. Würtele, AJM Miller, I. Siewert, S. Schneider J. Am. Chem. Soc., 2018, 140, 7922.
[4] I. Klopsch, M. Kinauer, M. Finger, C. Würtele, S. Schneider, Angew. Chem. Int. Ed. 2016, 55, 4786.