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

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(N CH 2 )(CH 2 SiMe 3 ) 2 . The reaction is reversible, and treatment of (η 5 -C 5 H 5 )Os(N CH 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 MeN PPh 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.