Stepwise Functionalization of N2 at Mo: Nitrido to Imido to Amido – Factors Favoring Amine Elimination from the Amido Complex

Abstract

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.