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Nitrogen reduction under mild conditions (room T and atmospheric P), using a non-fossil source of hydrogen remains a challenge. Molecular metal complexes, notably Mo based, have recently been shown to be active for such nitrogen fixation. We report electrochemical N 2 splitting with a Mo III triphosphino complex [(PPP)MoI 3 ], at room temperature and a moderately negative potential. A Mo IV nitride species was generated, which is confirmed by electrochemistry and NMR studies. The reaction goes through two successive one electron reductions of the starting Mo species, coordination of a N 2 molecule, and further splitting to a Mo IV nitride complex. Preliminary DFT studies support the formation of a bridging Mo I N 2 Mo I dinitrogen dimer evolving to the Mo nitride via a low energy transition state. This example joins a short list of molecular complexes for N 2 electrochemical reductive cleavage. It opens a door to electrochemical proton-coupled electron transfer (PCET) conversion studies of N 2 to NH 3 ., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Reactivity of (triphosphine)MoIV‐nitrido complex generated by N2 splitting, toward boranes is reported. The simple adduct Mo≡N→BH3 is observed with BH3.SMe2 while 1,2 addition is evidenced with 9‐BBN leading to H−Mo=NBR2. A second addition of BH3.SMe2 is facile and forms an unprecedented complex featuring two bridging H between two B and the Mo centers. Addition of PMe3 or BH3.SMe2 promotes reductive elimination and N−H bond formation. The full sequence of functionalization at Mo≡N obtained after N2 splitting is therefore evidenced in this work. [ABSTRACT FROM AUTHOR]

Two different dinitrogen‐derived molybdenum nitrido complexes varying by their geometry, ligand spheres and oxidations states were shown to engage their N ligand in dative bonding with the strong Lewis acid B(C6F5)3. The stable adducts were assessed for frustrated Lewis pair‐type heterolytic E−H bond splitting of hydrosilanes (E=Si) and HB(C6F5)2. Whereas Si−H bond activation was achieved, HB(C6F5)2 was shown to substitute B(C6F5)3 in a quantitative or equilibrated fashion, depending on the nature of the nitrido complex. No B−H bond splitting was observed. Thermodynamics of these reactions, computed by DFT, are in agreement with the experimental outcomes. [ABSTRACT FROM AUTHOR]

Nitrogen reduction under mild conditions (room T and atmospheric P), using a non‐fossil source of hydrogen remains a challenge. Molecular metal complexes, notably Mo based, have recently been shown to be active for such nitrogen fixation. We report electrochemical N2 splitting with a MoIII triphosphino complex [(PPP)MoI3], at room temperature and a moderately negative potential. A MoIV nitride species was generated, which is confirmed by electrochemistry and NMR studies. The reaction goes through two successive one electron reductions of the starting Mo species, coordination of a N2 molecule, and further splitting to a MoIV nitride complex. Preliminary DFT studies support the formation of a bridging MoIN2MoI dinitrogen dimer evolving to the Mo nitride via a low energy transition state. This example joins a short list of molecular complexes for N2 electrochemical reductive cleavage. It opens a door to electrochemical proton‐coupled electron transfer (PCET) conversion studies of N2 to NH3. [ABSTRACT FROM AUTHOR]

Catalytic formation of borylamines from atmospheric N2 is achieved for the first time using a series of homogenous (triphosphine)Mo complexes. Stepwise functionalization of the (triphosphine)Mo‐nitrido complex with chloroborane led to the synthesis of the imido complex. Electrochemical characterization of the (PPP)Mo‐nitrido and (PPP)Mo‐borylimido complexes showed that the latter is much more easily reduced. [ABSTRACT FROM AUTHOR]

Functionalization of nitrido complex [(PPhP2Cy)Mo(N)(I)] by a bis‐silane in concentrated medium generates the hydrido‐imido complex [(PPhP2Cy)Mo(H)(=NSiMe2CH2CH2SiMe2H)(I)]. Abstraction of the iodide by thallium salt TlX (X = PF6, OTf) results in a second N–Si bond formation and forms the bis‐hydride amide complex [(PPhP2Cy)Mo(H)2(NSiMe2CH2CH2SiMe2)]+. An alternative synthesis relies on the abstraction of the iodide from the nitride complex [(PPhP2Cy)Mo(N)(I)] to generate the corresponding cationic complex [(PPhP2Cy)Mo(N)]+ followed by addition of the bis‐silane. Addition of PMe3 to the [(PPhP2Cy)Mo(H)2(NSiMe2CH2CH2SiMe2)]+ complex liberates the silylamine and forms the Mo(II) cationic complex [(PPhP2Cy)Mo(H)(PMe3)]+. DFT calculations rationalizing the observed reactivity are presented. [ABSTRACT FROM AUTHOR]

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A homogeneous system which is able to yield silylamine from N2 and bis(silane) in one pot is reported. Mechanistically a {(triphosphine)molybdenum(I)} fragment, generated in situ, splits N2 into the corresponding nitrido complex at room temperature. Then, functionalization of the molybdenum nitrido is achieved by double Si−H addition under mild reaction conditions. Moreover, the bis(silyl)amine product is decoordinated from the metal center. [ABSTRACT FROM AUTHOR]

Keywords: molybdenum-nitrido complexes; N2 splitting; nitrile-alkyne cross-metathesis; nitriles; pincer ligands EN molybdenum-nitrido complexes N2 splitting nitrile-alkyne cross-metathesis nitriles pincer ligands 1 1 1 05/20/21 20210525 NES 210525 B Stickstoff-Fixierung b In der Zuschrift auf S. 12350 berichten Qian Liao, Nicolas Mézailles et al. über die direkte Synthese von Nitrilen aus Distickstoff unter milden Bedingungen. Molybdenum-nitrido complexes, N2 splitting, nitrile-alkyne cross-metathesis, nitriles, pincer ligands Frontispiz: Conversion of Dinitrogen into Nitrile: Cross-Metathesis of N2-Derived Molybdenum Nitride with Alkynes. [Extracted from the article]