Anionic Trinuclear Iridium(I) Oxo Complex: Synthesis and Reactivity as a Metal-Centered σ-Donor Ligand to Gold(I) and Silver(I)

Abstract

The diiridium(I) μ-hydroxo complex [Ir(μ-OH)(cod)] 2 (1; cod = 1,5-cyclooctadiene) readily reacted with aqueous NaOH in DMSO-d 6 or NaN(SiMe 3 ) 2 in THF to give the anionic trinuclear iridium oxo complex Na[{Ir(cod)) upon recrystallization from THF−hexane. Reactions of 2 with group 11 metal electrophiles (AuCl(PPh 3 ), AgCl(PPh 3 ), and AgCl) afforded iridium−gold and −silver mixed-metal cluster complexes [{Ir(cod)} 3 (μ 3 -O) 2 M(PPh 3 )] (3a: M = Au; 3b: M = Ag) and [Na(dmso) 3 (μ-dmso)] 2 [{Ir(cod)} 3 (μ 3 -O) 2 Ag(μ-Cl)] 2 (4) containing Ir(I) → Au(I)/Ag(I) dative interactions as revealed by DFT and NBO analysis. These results demonstrate the ability of 2 to act as an iridium(I)-centered σ-donor ligands to the group 11 metal centers. Single-crystal X-ray structures of 2•(THF) 2 (H 2 O), 3a, 3b, and 4 are presented.

Effect of distal metal species on lewis basicity of a μ3-oxo ligand in a doubly oxo-bridged (μ3-O)[Rh(cod)]3(μ4-O)M core

“…The structure of 1 containing a μ 4 -oxo ligand was different from that reported by Matsuzaka et al for the iridium variants; an oxo-bridged trinuclear iridium complex with an Au(PPh 3 ) fragment was synthesized by the reaction of (μ 3 -O)[Ir(cod)] 3 (μ 3 -O)K(THF) 2 with AuCl(PPh 3 ), in which the Au fragment positions one of the three Ir( i )–Ir( i ) edges of the (μ 3 -O) 2 Ir 3 core to form two Ir( i )–Au( i ) dative bonds. 10 …”