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dc.contributor.authorGouré, Eric
dc.contributor.authorAvenier, Priscilla
dc.contributor.authorSoláns, Xavier Luis
dc.contributor.authorVeyre, Laurent
dc.contributor.authorBaudouin, Anne Christine
dc.contributor.authorKaya, Yasemin
dc.contributor.authorTaoufik, Mostafa
dc.contributor.authorBasset, Jean-Marie
dc.contributor.authorEisenstein, Odile
dc.contributor.authorQuadrelli, Elsje Alessandra
dc.date.accessioned2015-08-03T09:01:19Z
dc.date.available2015-08-03T09:01:19Z
dc.date.issued2011
dc.identifier.issn11440546
dc.identifier.doi10.1039/c1nj20032a
dc.identifier.urihttp://hdl.handle.net/10754/561647
dc.description.abstractAmmonia N-H bond is cleaved at room temperature by the silica-supported tantalum imido amido complex [(≡SiO)2Ta(NH)(-NH2)], 2, if excess ammonia is present, but requires 150 °C to achieve the same reaction if only one equivalent NH3 is added to 2. MAS solid-state 15N NMR and in situ IR spectroscopic studies of the reaction of either 15N or 2H labeled ammonia with 2 show that initial coordination of the ammonia is followed by scrambling of either 15N or 2H among ammonia, amido and imido groups. Density functional theory (DFT) calculations with a cluster model [{(μ-O)[(H3SiO) 2SiO]2}Ta(NH)(-NH2)(NH3)], 2 q·NH3, show that the intramolecular H transfer from Ta-NH2 to TaNH is ruled out, but the H transfers from the coordinated ammonia to the amido and imido groups have accessible energy barriers. The energy barrier for the ammonia N-H activation by the Ta-amido group is energetically preferred relative to the Ta-imido group. The importance of excess NH3 for getting full isotope scrambling is rationalized by an outer sphere assistance of ammonia acting as proton transfer agent, which equalizes the energy barriers for H transfer from coordinated ammonia to the amido and imido groups. In contrast, additional coordinated ammonia does not favor significantly the H transfer. These results rationalize the experimental conditions used. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2011.
dc.publisherRoyal Society of Chemistry (RSC)
dc.titleHeterolytic cleavage of ammonia N-H bond by bifunctional activation in silica-grafted single site Ta(V) imido amido surface complex. Importance of the outer sphere NH3 assistance
dc.typeArticle
dc.contributor.departmentChemical Science Program
dc.contributor.departmentKAUST Catalysis Center (KCC)
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalNew Journal of Chemistry
dc.contributor.institutionUniversité de Lyon, UMR 5265 C2P2, (UCBL Lyon 1- CPE Lyon -CNRS), École Supérieure Chimie Physique Electronique, 43 Boulevard du 11 Novembre 1918, Villeurbanne, France
dc.contributor.institutionDepartament de Quimica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
dc.contributor.institutionInstitut Charles Gerhardt, Université Montpellier 2, CNRS 5253, cc 1501 Place E. Bataillon, 34095 Montpellier, France
dc.contributor.institutionGorlaeus Laboratories, Universiteit Leiden, Leiden Institute of Chemistry, Einsteinweg 55, 2333 CC Leiden, Netherlands
dc.contributor.institutionIFP-Lyon, Rond-Point de LEchangeur de Solaize, BP3, 69360, France
kaust.personBasset, Jean-Marie


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