title: Ammonia formation by metal-ligand cooperative hydrogenolysis of a nitrido ligand.
abstract: Bioinspired hydrogenation of N(2) to ammonia at ambient conditions by stepwise nitrogen protonation/reduction with metal complexes in solution has experienced remarkable progress. In contrast, the highly desirable direct hydrogenation with H(2) remains difficult. In analogy to the heterogeneously catalysed Haber-Bosch process, such a reaction is conceivable via metal-centred N(2) splitting and unprecedented hydrogenolysis of the nitrido ligands to ammonia. We report the synthesis of a ruthenium(IV) nitrido complex. The high nucleophilicity of the nitrido ligand is demonstrated by unusual N-C coupling with π-acidic CO. Furthermore, the terminal nitrido ligand undergoes facile hydrogenolysis with H(2) at ambient conditions to produce ammonia in high yield. Kinetic and quantum chemical examinations of this reaction suggest cooperative behaviour of a phosphorus-nitrogen-phosphorus pincer ligand in rate-determining heterolytic hydrogen splitting.
authors.affiliation: Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85748 Garching b. München, Germany.
authors.forename: Bjorn
authors.initials: B
authors.lastname: Askevold
authors.forename: Jorge Torres
authors.initials: JT
authors.lastname: Nieto
authors.forename: Samat
authors.initials: S
authors.lastname: Tussupbayev
authors.forename: Martin
authors.initials: M
authors.lastname: Diefenbach
authors.forename: Eberhardt
authors.initials: E
authors.lastname: Herdtweck
authors.forename: Max C
authors.initials: MC
authors.lastname: Holthausen
authors.forename: Sven
authors.initials: S
authors.lastname: Schneider
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D000641:Ammonia; D012428:Ruthenium; D006859:Hydrogen; D009584:Nitrogen