Reactivity of Dinitrogen Bound to Mid‐ and Late‐Transition‐Metal Centers

Abstract

This review presents a comprehensive overview of the reactions of N 2 within the coordination sphere of transition metals of groups 6 to 9. Many of these metals mediate the reaction of N 2 with protons under reductive conditions, which can lead to the (catalytic) formation of ammonia or hydrazine, and the mechanisms of these reactions somewhat resemble the mode of action of nitrogenase enzymes. Alternatively, coordinated N 2 can react with carbon and silicon electrophiles and radicals to allow, for example, the catalytic formation of[a] Van '567 silylamines. Another approach in N 2 activation involves the homolytic splitting of dinitrogen to form intermediate nitrides in analogy to the Haber-Bosch process. Thus formed nitrides can undergo follow-up reactions with protons or carbon electrophiles. Molybdenum, tungsten, and iron reveal the richest chemistry of coordinated N 2 ; however, chromium, manganese, rhenium, osmium, and cobalt systems provide alternative pathways in the making and breaking of bonds on the dinitrogen molecule.Nitesh Khoenkhoen (1989) received his Bachelor of Science degree in chemistry at Utrecht University, The Netherlands, where he participated in undergraduate research under the supervision of Prof. Petra E. de Jongh in the area of inorganic chemistry and catalysis. After a short internship at the University of Amsterdam, he moved to the VU University Amsterdam, where he is currently a master's student in the laboratory of Professor Koop Lammertsma and is studying the generation of free phosphinidenes. Bas de Bruin (1971) did his PhD research at the RUN in Nijmegen (Prof. A. W. Gal, 1999). He did his postdoctoral research at the MPI für Bio-Anorganische Chemie in Mülheim a/d Ruhr (Prof. K. Wieghardt), after which he returned to the RUN as an assistant professor. In 2005, he moved to the University of Amsterdam (UvA, The Netherlands), where he was promoted to associate professor in 2008 and to full professor in 2013. He is involved in various research activities, including radical organometallic chemistry, EPR spectroscopy, olefin oxygenation, polymer synthesis, mechanistic studies, and computational catalysis with a focus on the development of new (bio-inspired) catalytic transformations. Joost N. H. Reek (1967) completed his PhD in Nijmegen with a thesis on supramolecular chemistry (Prof. Nolte). After a postdoctoral fellowship in Sydney Australia with Prof. Crossley, he joined the group of Prof. van Leeuwen at the University of Amsterdam (UvA, The Netherlands) as an assistant professor (1998), where he started research activities that focused on transition-metal catalysis. He was promoted to associate professor in 2003, and in 2006 he became full professor and elected member of the Young Royal Academy of Science. In 2009, he started a spin-off company (InCatT) to explore the commercial potential of new supramolecular strategies for combinatorial approaches in (asymmetric) catalysis. In 2013, he became the director of the Van 't Hoff Institute for Molecular Science. His current research ...

Insight into the Iron–Molybdenum Cofactor of Nitrogenase from Synthetic Iron Complexes with Sulfur, Carbon, and Hydride Ligands

“…61,157,191,192,41,44,165 Peters has shown that phosphine ligands provide excellent platforms for functionalization of N 2 on iron, 60,193,194 and enable characterization of potential N 2 reduction intermediates Fe-N x H y , 98,99,165,194–196 including systems that feature a coordinated hydride. 40,42,43 Ammonia production by tripodal trisphosphine ligands with an axial donor (Si, C, or B) increases in the order Si < C < B. 165 The higher degree of Fe-heteroatom bond flexibility in 42 could be crucial for stabilizing the variety of N 2 reduction intermediates in the catalytic cycle.…”

A Synthetic Single-Site Fe Nitrogenase: High Turnover, Freeze-Quench 57Fe Mössbauer Data, and a Hydride Resting State

“…6 This search has yielded systems capable of the catalytic reduction of N 2 to hydrazine (N 2 H 4 ), 7 tris(trimethylsilyl)amine, 8 and a few examples of the direct catalytic fixation of N 2 to NH 3 (Chart 1). 8g,9,10,11,12 While a wealth of mechanistic information for the original Mo catalyst system developed by Schrock has been derived from stoichiometric studies and theory, 13,14 in situ spectroscopic studies during catalysis were not reported.…”

Catalytic Nitrogen-to-Ammonia Conversion by Osmium and Ruthenium Complexes

“…12 Germane to our present interest, the identification and study of a homologous, isostructural series of complexes (Fe, Ru, Os) will help to better delineate some of the key factors for N 2 RR catalyst design.…”