Dinitrogen Dissociation on an Isolated Surface Tantalum Atom
P. Avenier,1
M. Taoufik,1*
A. Lesage,2
X. Solans-Monfort,3
A. Baudouin,1
A. de Mallmann,1
L. Veyre,
J.-M. Basset,1*
O. Eisenstein,4
L. Emsley,2
E. A. Quadrelli1*
Both industrial and biochemical ammonia syntheses are thought to rely on the cooperation of multiple metals in breaking the strong triple bond of dinitrogen. Such multimetallic cooperation for dinitrogen cleavage is also the general rule for dinitrogen reductive cleavage with molecular systems and surfaces. We have observed cleavage of dinitrogen at 250°C and atmospheric pressure by dihydrogen on isolated silica surface–supported tantalum(III) and tantalum(V) hydride centers [(
Si-O)2TaIII-H] and [(Si-O)2TaVH3], leading to the TaV amido imido product [(SiO)2Ta(=NH)(NH2)]: We assigned the product structure based on extensive characterization by infrared and solid-state nuclear magnetic resonance spectroscopy, isotopic labeling studies, and supporting data from x-ray absorption and theoretical simulations. Reaction intermediates revealed by in situ monitoring of the reaction with infrared spectroscopy support a mechanism highly distinct from those previously observed in enzymatic, organometallic, and heterogeneous N2 activating systems.
1 Université de Lyon, C2P2, Laboratoire de Chimie Organométallique de Surface UMR5265 CNRS-CPE-UCBL1 43, Boulevard du 11 Novembre 1918, BP 2077 F-69616, Villeurbanne Cedex, France.
2 Université de Lyon, Laboratoire de Chimie, UMR-5182 CNRS-ENS, Lyon, Ecole Normale Supérieure de Lyon, F-69364 Lyon Cedex, France.
3 Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
4 Institut Charles Gerhardt, UMR 5253 CNRS, UM 2- ENSCM, UM1, Chimie Théorique, Méthodologies, Modélisations, Université Montpellier 2, F-34095 Montpellier Cedex 05, France.
* To whom correspondence should be addressed. E-mail: quadrelli{at}cpe.fr (E.A.Q.); taoufik{at}cpe.fr (M.T.); basset{at}cpe.fr (J.-M.B.)
