Reactivity of the Imido Group in [CpOs(NCH₃)(CH₂SiMe₃)₂][SO₃CF₃]

Abstract

The imido ligand in [(η 5 -C 5 H 5 )Os(NCH 3 )(CH 2 SiMe 3 ) 2 ][SO 3 CF 3 ] reacts with basic and nucleophilic molecules. Triphenylphosphine, pyridine, and water act as bases and deprotonate the methylimido ligand forming the first osmium(IV) methyleneamido complex, (η 5 -C 5 H 5 )Os(NdCH 2 )(CH 2 SiMe 3 ) 2 . The reaction is reversible, and treatment of (η 5 -C 5 H 5 )-Os(NdCH 2 )(CH 2 SiMe 3 ) 2 with HBF 4 produces [(η 5 -C 5 H 5 )Os(NCH 3 )(CH 2 SiMe 3 ) 2 ][BF 4 ]. Triphenylphosphine also abstracts the imido ligand to form MeNdPPh 3 . The imido complex reacts with ethylene to produce an olefin complex, [(η 5 -C 5 H 5 )Os(NHCH 2 )(CH 2 CH 2 ) 2 ][SO 3 -CF 3 ]. Under pressures of ethylene, products resulting from imide transfer to the olefin are obtained.

Formation of a Methyleneimine Moiety by Reaction of a RuII‐Coordinated Azide Ion with Methyl Iodide

“…The δ value of the hydrogen atom of the imine is similar to that of the CH 2 NH‐ κN and ‐ κ 2 N , C 10. The 13 C NMR spectrum shows a signal at 172.42 ppm, which was assigned to the carbon atoms of the methyleneimine, analogously to that of the known Os complex 10d…”

“…A few metal complexes containing a methyleneimine moiety (NHCH 2 ) have been synthesized by the reaction of a methylhydrazine or methylimido complex 10. The NHCH 2 ligand coordinates through two coordination modes; one is the N‐monodentate mode ( κN ) of a rhenium complex10a–c and another the N , C ‐bidentate one ( κ 2 N , C ) of an osmium complex 10d. Only one rhenium complex containing an methyleneimine‐ κN moiety has been characterized by X‐ray crystallography 10c.…”

Preparation and Reactivity of Hydrazine Complexes of Rhenium: Synthesis of 1,2‐Diazene (NH=NH) and Methyleneimine (CH2=NH) Derivatives

“…As a ligand, it has been found in only one case, through π-coordination to an osmium centre, [23] and no other report has been found on this molecule, which displays a simple constitution and structure and whose chemical properties are still unknown.…”

Terminal Nitrido and Imido Complexes of the Late Transition Metals

“…[181] Other Os compounds that have been prepared include OsF 5 (NCl), [182] in addition to several organometallic compounds. [183][184][185][186] Pseudotetrahedral imido complexes (VII), have been known since 1959, when Milas and Iliopulos discovered that the Os = O groups in OsO 4 could be exchanged for Os=NR groups. [187] The use of OsO 3 (NR) compounds in amino-hydroxylation of alkenes was pioneered by Sharpless.…”