Rhodium and Iridium Hydroxide Complexes [M(μ-OH)(COD)]₂(M = Rh, Ir) as Versatile Precursors of Homo and Early−Late Heterobimetallic Compounds. X-ray Crystal Structures of Cp*Ta(μ₃-O)₄[Rh(COD)]₄(Cp* = η⁵-C₅Me₅) and [Ir(2-O-3-CN-4,6-Me₂-C₅HN)(COD)]₂

Abstract

The reaction of Cp*TiMe3 with 3 equiv of [Ir(μ-OH)(COD)]2 affords the new heterometallic organometallic oxide Cp*Ti(μ3-O)3[Ir(COD)]3 (3). Reaction of Cp*TaMe4 with 4 equiv of [M(μ-OH)(COD)]2 (M = Rh, Ir) yields complexes Cp*Ta(μ3-O)4[M(COD)]4 [M = Rh (5), Ir (6)]. The structure of compound 5 has been determined by X-ray diffraction. Complexes 5 and 6 react with the alcohol 3-CN-4,6-Me2-2-OH−C5HN to yield the corresponding rhodium (7) or iridium (8) alkoxide complexes. The structure of complex 8 has been determined by X-ray diffraction. Reaction of [Rh(μ-OH)(COD)]2 with thiolacetic acid gives rise to a thioacetate complex [Rh(μ-SCOCH3)(COD)]2 (9).

Selective Hydration of Nitriles to Corresponding Amides in Air with Rh(I)-N-Heterocyclic Complex Catalysts

“…Column chromatography was performed on silica gel (70-230 mesh, 63-200 µm, Sigma-Aldrich). The metal precursors [RhCl(cod)] 2 [60], [Rh(OH)(cod)] 2 [61], the ligands PTA [62], and mtppms-Na [63] were prepared by the methods described in the literature.…”

Redox Isomerization of Allylic Alcohols Catalyzed by New Water-Soluble Rh(I)-N-Heterocyclic Carbene Complexes

“…The water-soluble phosphine ligands pta [58], mtppts-Na3 [59], and mtppms-Na [60], the water soluble [sSIMesH]Cl [25], and the metal precursors [RhCl(cod)]2 [61], [Rh(OH)(cod)]2 [62] were prepared according to literature methods. According to the suggested mechanism, in the first step of the catalytic cycle, a deprotonated allylic alcohol coordinates to the metal complex, both with its olefinic bond, and the oxygen donor atom.…”

“…The water-soluble phosphine ligands pta [58], mtppts-Na 3 [59], and mtppms-Na [60], the water soluble [sSIMesH]Cl [25], and the metal precursors [RhCl(cod)] 2 [61], [Rh(OH)(cod)] 2 [62] were prepared according to literature methods.…”

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

“…Iridium oxo complexes have attracted considerable attention due to their applications in oxygen atom transfer reactions. − The formation of iridium oxo complexes from their hydroxo or aquo precursors is of relevance to the iridium-catalyzed water oxidation but has limited experimental precedents. ,− The dimeric iridium­(I) hydroxo complex [Ir­(μ-OH)­(cod)] 2 ( 1 ) is a readily accessible starting material in organoiridium chemistry and is expected to give iridium oxo complexes via O–H bond scission. Earlier reports concerning the synthesis of iridium oxo complexes from 1 involved its reaction with titanium and tantalum alkyls, which afforded μ 3 -oxo-bridged early late heterobimetallic complexes . More recently, complex 1 was shown to undergo a spontaneous dehydrative condensation to afford a pentanuclear iridium oxo complex: …”

“…Earlier reports concerning the synthesis of iridium oxo complexes from 1 involved its reaction with titanium and tantalum alkyls, which afforded μ 3 -oxo-bridged early late heterobimetallic complexes. 5 More recently, complex 1 was shown to undergo a spontaneous dehydrative condensation to afford a pentanuclear iridium oxo complex: 6 Our interest in iridium oxo complexes stems from their use as precursors of iridium−gold mixed-metal clusters. Mixedmetal clusters can serve as precursors of supported bimetallic nanoparticles.…”