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

Title Catalytic Nitrogen-to-Ammonia Conversion by Osmium and Ruthenium Complexes.
Authors J. Fajardo; J.C. Peters
Journal J Am Chem Soc
DOI 10.1021/jacs.7b10204
Abstract

Despite the critical role Ru and Os complexes have played in the development of transition metal dinitrogen chemistry, they have not been shown to mediate catalytic N2-to-NH3 conversion (N2RR), nor have M-NxHy complexes been derived from protonation of their M-N2 precursors. To help delineate factors for N2RR catalysis, we report on isostructural tris(phosphino)silyl Ru and Os complexes that mediate catalytic N2RR, and compare their activities with an isostructural Fe complex. The Os system is most active, and liberates more than 120 equiv NH3 per Os center in a single batch experiment using Cp*2Co and [H2NPh2][OTf] as reductant and acid source. Isostructural Ru and Fe complexes generate little NH3 under the same conditions. Protonation of Os-N2- affords a structurally characterized Os=NNH2+ hydrazido species that mediates NH3 generation, suggesting it is a plausible intermediate of the catalysis. Inactive Os hydrides are characterized that form during catalysis.

Citation J. Fajardo; J.C. Peters.Catalytic Nitrogen-to-Ammonia Conversion by Osmium and Ruthenium Complexes.. J Am Chem Soc. 2017;139(45):1610516108. doi:10.1021/jacs.7b10204

Related Elements

Osmium

See more Osmium products. Osmium (atomic symbol: Os, atomic number: 76) is a Block D, Group 8, Period 6 element with an atomic weight of 190.23. Osmium Bohr ModelThe number of electrons in each of osmium's shells is [2, 8, 18, 32, 14, 2] and its electron configuration is [Xe] 4f14 5d6 6s2. The osmium atom has a radius of 135 pm and a Van der Waals radius of 216 pm. Osmium was discovered and first isolated by Smithson Tennant in 1803. Elemental OsmiumIn its elemental form, osmium has a silvery blue cast apperance. Osmium has the highest melting point and the lowest vapor pressure of any of the platinum group of metals it is also the densest naturally ocurring element. Osmium is the least abundant stable element in the earth's crust. It is found in the alloys osmiridium and iridiosmium and as a free element. The origin of the name Osmium comes from the Greek word osme, meaning a smell or odor.

Ruthenium

See more Ruthenium products. Ruthenium (atomic symbol: Ru, atomic number: 44) is a Block D, Group 8, Period 5 element with an atomic weight of 101.07. Ruthenium Bohr ModelThe number of electrons in each of ruthenium's shells is [2, 8, 18, 15, 1] and its electron configuration is [Kr] 4d7 5s1. The ruthenium atom has a radius of 134 pm and a Van der Waals radius of 207 pm. Ruthenium was discovered by Jędrzej Śniadecki in 1807. It was first recognized as a distinct element by Karl Ernst Claus in 1844. Elemental RutheniumIn its elemental form, ruthenium has a silvery white metallic appearance. Ruthenium is a rare transition metal belonging to the platinum group of metals. It is found in pentlandite, pyroxenite, and platinum group metal ores. The name Ruthenium originates from the Latin word "Ruthenia," meaning Russia.

Related Forms & Applications