Conférence

- ABSTRACT -
How can we functionalize N2? Metal complexes or not?
Nature is able to reduce N2 into NH3 under mild conditions, using the enzymes nitrogenases. Despite intense researches during the past decades, metal complexes capable of achieving the reduction of N2 into either NH3 or amines are rare. As early as 1989, Hidai has shown that a Mo(0) complex could catalyze the formation of silylamine from N2, while Schrock reported the first catalytic N2-to-NH3 process using a Mo(III) complex in 2003. Design of more efficient catalysts rely on a precise mechanistic understanding of the 6 e-/6 E+ (E = H or Si) transfer to N2. We have developed the use of a tri and tetradentate phosphine ligand/Mo complexes which not only allow catalytic functionalization of N2, but also the isolation of several intermediates.[1,2] We have moreover shown that the direct splitting of N2 can be achieved at the (PP2)Mo fragment to form the corresponding Mo-nitrido.[3] This complex can be functionalized under mild conditions (room temperature to mild heating) by E-H (E = Si, B) bonds to generate the corresponding amine NE3 and/or NE2H, that is liberated from the Mo center.[4-6] These studies have allowed the development of the first Mo catalyzed borylation of N2.[7]
Beyond the use of Mo complexes for N2 fixation, we have uncovered most recently that some radicals are able to activate N2.[8]
I will share these results with you.
[1] Q. Liao, N. Saffon-Merceron, N. Mézailles, Angew. Chem., Int. Ed., 2014, 53, 14206.
[2] Q. Liao, N. Saffon-Merceron, N. Mézailles, ACS. Cat., 2015, 5, 6902.
[3] L. Merakeb, S. Bennaamane, J. De Freitas, E. Clot, N. Mézailles, M. Robert, Angew. Chem., Int. Ed., 2022, 61, e202209899. doi.org/10.1002/anie.202209899
[4] Q. Liao, A. Cavaillé, N. Saffon-Merceron, N. Mézailles, Angew. Chem., Int. Ed., 2016, 55, 11212.
[5] M. Fernandez-Espada, S. Bennaamane, Q. Liao, N. Saffon-Merceron, S. Massou, E. Clot, N. Nebra, M. Fustier-Boutignon, N. Mézailles, Angew. Chem., Int. Ed., 2018, 57, 12865.
[6] S. Bennaamane, M. Fernandez-Espada, I. Yagoub, N. Saffon-Merceron, M. Fustier-Boutignon, N. Nebra, E. Clot, N. Mézailles, Eur. J. Inorg. Chem., 2020, 1499. Special issue on Nitrogen Fixation.
[7] S. Bennaamane, M. Espada, A. Mulas, T. Personeni, N. Saffon-Merceron, M. Fustier-Boutignon, C. Bucher, N. Mézailles, Angew. Chem., Int. Ed. 2021, 60, 20210. doi.org/10.1002/anie.202106025.
[8] Bennaamane, S. ; Rialland, B. ; Khrouz, L. ; Fustier-Boutignon, M. ; Bucher, C. ; Clot, E. ; Mézailles, N. Angew. Chem.Int. Ed. 2023, 62, e202209102. doi.org/10.1002/anie.202209102.
Date de l'évènement : mardi 14 mai
Heure : 10h30 - 12h10
Lieu : salle de conférences de l'ISM (3e étage)
Contacts : Patrick TOULLEC & Conférences ISM