N-Heterocyclic Carbene-Arsinidenide Iridium Complexes

Abstract

Half-sandwich iridium complexes of the type [(η5-C5Me5){(NHC)E}IrCl] (E=P, As) were prepared by the reactions of N-heterocyclic carbene (NHC) adducts of trimethylsilylphosphinidene and trimethylsilylarsinidene, (IDipp)ESiMe3 and (IMes)ESiMe3, with [(η5-C5Me5)IrCl2]2 (IDipp=bis(2,6-diisopropylphenyl)imidazolin-2-ylidene; IMes=1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene). The molecular structure of [(η5-C5Me5){(IDipp)As}IrCl] was established by X-ray diffraction analysis, affording the first structurally authenticated NHC-arsinidenide complex with a short Ir−As bond length that reveals a significant degree of metal-arsenic π-interaction as also confirmed by theoretical calculations.