Pentamethylcyclopentadienyl iridium dichloride dimer

Last updated
Pentamethylcyclopentadienyl iridium dichloride dimer
Cp*2Ir2Cl4 2023.svg
Names
IUPAC name
Di-μ-chloro-bis[chloro(pentamethylcyclopentadienyl)iridium(III)]
Other names
Dichloro(pentamethylcyclopentadienyl)iridium(III)
Identifiers
3D model (JSmol)
ECHA InfoCard 100.205.779 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/2C10H16.4ClH.2Ir/c2*1-6-7(2)9(4)10(5)8(6)3;;;;;;/h2*6H,1-5H3;4*1H;;/p-4
    Key: PGQVOTGCKISIMD-UHFFFAOYSA-J
  • c1(C)=c(C)c(C)=c(C)c1(C)[Ir](Cl)(Cl1)Cl[Ir](Cl)1C1(C)C(C)=C(C)C(C)=C1C
Properties
C20H30Cl4Ir2
Molar mass 796.71 g/mol
Appearanceorange solid
Melting point >230 °C
Dichloromethane, Chloroform
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Pentamethylcyclopentadienyl iridium dichloride dimer is an organometallic compound with the formula [(C5(CH3)5IrCl2)]2, commonly abbreviated [Cp*IrCl2]2 This bright orange air-stable diamagnetic solid is a reagent in organometallic chemistry. [1]

Contents

Structure

The compound has C2h symmetry. Each metal is pseudo-octahedral. The terminal and bridging Ir-Cl bonds have the lengths 2.39 and 2.45 Å, respectively.

Preparation, reactions

Pentamethylcyclopentadienyl iridium dichloride dimer was first prepared by the reaction of hydrated iridium trichloride with hexamethyl Dewar benzene. [2] More conveniently, the compound is prepared by the reaction of hydrated iridium trichloride and pentamethylcyclopentadiene in hot methanol, from which the product precipitates [1]

2 Cp*H + 2 IrCl3(H2O)3 → [Cp*IrCl2]2 + 2 HCl + 6 H2O

The Ir- μ -Cl bonds are labile and can be cleaved to give a variety of adducts of the general formula Cp*IrCl2L. Such adducts undergo further substitution to afford cations [Cp*IrClL2]+ and [Cp*IrL3]2+. The chloride ligands can also be replaced by other anions such as carboxylates, nitrite, and azide.

Reduction of [Cp*IrCl2]2 in the presence of CO affords [Cp*Ir(CO)2], which can be decarbonylated to give the unsaturated derivative [Cp*Ir(CO)]2. [3] Treatment of [Cp*IrCl2]2 with borohydride under an atmosphere of H2 gives the iridium(V) derivative Cp*IrH4.

[Cp*IrCl2]2 is a precursor to catalysts for the asymmetric transfer hydrogenation of ketones. [4]

Related Research Articles

<span class="mw-page-title-main">Aluminium chloride</span> Chemical compound

Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula AlCl3. It forms a hexahydrate with the formula [Al(H2O)6]Cl3, containing six water molecules of hydration. Both the anhydrous form and the hexahydrate are colourless crystals, but samples are often contaminated with iron(III) chloride, giving them a yellow colour.

<span class="mw-page-title-main">Wilkinson's catalyst</span> Chemical compound

Wilkinson's catalyst (chlorido­tris(triphenylphosphene)­rhodium(I)) is a coordination complex of rhodium with the formula [RhCl(PPh3)3], where 'Ph' denotes a phenyl group. It is a red-brown colored solid that is soluble in hydrocarbon solvents such as benzene, and more so in tetrahydrofuran or chlorinated solvents such as dichloromethane. The compound is widely used as a catalyst for hydrogenation of alkenes. It is named after chemist and Nobel laureate Sir Geoffrey Wilkinson, who first popularized its use.

<span class="mw-page-title-main">Trimethylaluminium</span> Chemical compound

Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2(CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industrially important compound, closely related to triethylaluminium.

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic solids featuring octahedral Rh(III) centres. Depending on the value of n, the material is either a dense brown solid or a soluble reddish salt. The soluble trihydrated (n = 3) salt is widely used to prepare compounds used in homogeneous catalysis, notably for the industrial production of acetic acid and hydroformylation.

<span class="mw-page-title-main">Iridium(III) chloride</span> Chemical compound

Iridium(III) chloride is the inorganic compound with the formula IrCl3. The anhydrous compound is relatively rare, but the related hydrate is much more commonly encountered. The anhydrous salt has two polymorphs, α and β, which are brown and red colored respectively. More commonly encountered is the hygroscopic dark green trihydrate IrCl3(H2O)3 which is a common starting point for iridium chemistry.

<span class="mw-page-title-main">Ruthenium(III) chloride</span> Chemical compound

Ruthenium(III) chloride is the chemical compound with the formula RuCl3. "Ruthenium(III) chloride" more commonly refers to the hydrate RuCl3·xH2O. Both the anhydrous and hydrated species are dark brown or black solids. The hydrate, with a varying proportion of water of crystallization, often approximating to a trihydrate, is a commonly used starting material in ruthenium chemistry.

<span class="mw-page-title-main">Crabtree's catalyst</span> Chemical compound

Crabtree's catalyst is an organoiridium compound with the formula [C8H12IrP(C6H11)3C5H5N]PF6. It is a homogeneous catalyst for hydrogenation and hydrogen-transfer reactions, developed by Robert H. Crabtree. This air stable orange solid is commercially available and known for its directed hydrogenation to give trans stereoselectivity with respective of directing group.

<span class="mw-page-title-main">Pentamethylcyclopentadiene</span> Chemical compound

1,2,3,4,5-Pentamethylcyclopentadiene is a cyclic diene with the formula C5(CH3)5H, often written C5Me5H, where Me is CH3. It is a colorless liquid.

<span class="mw-page-title-main">Titanocene dichloride</span> Chemical compound

Titanocene dichloride is the organotitanium compound with the formula (η5-C5H5)2TiCl2, commonly abbreviated as Cp2TiCl2. This metallocene is a common reagent in organometallic and organic synthesis. It exists as a bright red solid that slowly hydrolyzes in air. It shows antitumour activity and was the first non-platinum complex to undergo clinical trials as a chemotherapy drug.

<span class="mw-page-title-main">Dewar benzene</span> Chemical compound

Dewar benzene (also spelled dewarbenzene) or bicyclo[2.2.0]hexa-2,5-diene is a bicyclic isomer of benzene with the molecular formula C6H6. The compound is named after James Dewar who included this structure in a list of possible C6H6 structures in 1869. However, he did not propose it as the structure of benzene, and in fact he supported the correct structure previously proposed by August Kekulé in 1865.

<span class="mw-page-title-main">Cyclooctadiene rhodium chloride dimer</span> Chemical compound

Cyclooctadiene rhodium chloride dimer is the organorhodium compound with the formula Rh2Cl2(C8H12)2, commonly abbreviated [RhCl(COD)]2 or Rh2Cl2(COD)2. This yellow-orange, air-stable compound is a widely used precursor to homogeneous catalysts.

Martin Arthur Bennett FRS is an Australian inorganic chemist. He gained recognition for studies on the co-ordination chemistry of tertiary phosphines, olefins, and acetylenes, and the relationship of their behaviour to homogeneous catalysis.

<span class="mw-page-title-main">(Cymene)ruthenium dichloride dimer</span> Chemical compound

(Cymene)ruthenium dichloride dimer is the organometallic compound with the formula [(cymene)RuCl2]2. This red-coloured, diamagnetic solid is a reagent in organometallic chemistry and homogeneous catalysis. The complex is structurally similar to (benzene)ruthenium dichloride dimer.

<span class="mw-page-title-main">Organoiridium chemistry</span> Chemistry of organometallic compounds containing an iridium-carbon bond

Organoiridium chemistry is the chemistry of organometallic compounds containing an iridium-carbon chemical bond. Organoiridium compounds are relevant to many important processes including olefin hydrogenation and the industrial synthesis of acetic acid. They are also of great academic interest because of the diversity of the reactions and their relevance to the synthesis of fine chemicals.

<span class="mw-page-title-main">Organorhodium chemistry</span> Field of study

Organorhodium chemistry is the chemistry of organometallic compounds containing a rhodium-carbon chemical bond, and the study of rhodium and rhodium compounds as catalysts in organic reactions.

<span class="mw-page-title-main">Peter Maitlis</span> British chemist (1933–2022)

Peter Michael Maitlis, FRS was a British organometallic chemist.

<span class="mw-page-title-main">Pentamethylcyclopentadienyl ruthenium dichloride dimer</span> Chemical compound

Pentamethylcyclopentadienyl ruthenium dichloride is an organoruthenium chemistry with the formula [(C5(CH3)5)RuCl2]2, commonly abbreviated [Cp*RuCl2]2. This brown paramagnetic solid is a reagent in organometallic chemistry. It is an unusual example of a compound that exists as isomers that differ in the intermetallic separation, a difference that is manifested in a number of physical properties.

<span class="mw-page-title-main">Rhodium carbonyl chloride</span> Chemical compound

Rhodium carbonyl chloride is an organorhodium compound with the formula Rh2Cl2(CO)4. It is a red-brown volatile solid that is soluble in nonpolar organic solvents. It is a precursor to other rhodium carbonyl complexes, some of which are useful in homogeneous catalysis.

<span class="mw-page-title-main">Pentamethylcyclopentadienyl rhodium dichloride dimer</span> Chemical compound

Pentamethylcyclopentadienyl rhodium dichloride dimer is an organometallic compound with the formula [(C5(CH3)5RhCl2)]2, commonly abbreviated [Cp*RhCl2]2 This dark red air-stable diamagnetic solid is a reagent in organometallic chemistry.

Iridium compounds are compounds containing the element iridium (Ir). Iridium forms compounds in oxidation states between −3 and +9, but the most common oxidation states are +1, +2, +3, and +4. Well-characterized compounds containing iridium in the +6 oxidation state include IrF6 and the oxides Sr2MgIrO6 and Sr2CaIrO6. iridium(VIII) oxide was generated under matrix isolation conditions at 6 K in argon. The highest oxidation state (+9), which is also the highest recorded for any element, is found in gaseous [IrO4]+.

References

  1. 1 2 White, C.; Yates, A.; Maitlis, P. M. (1992). (η5-Pentamethylcyclopentadienyl)Rhodium and -Iridium Compounds. Inorganic Syntheses. Vol. 29. pp. 228–234. doi:10.1002/9780470132609.ch53. ISBN   9780471544708.{{cite book}}: |journal= ignored (help)
  2. ↑ Kang, Jung W.; Moseley, K.; Maitlis, Peter M. (1969). "Pentamethylcyclopentadienylrhodium and -iridium halides. I. Synthesis and properties". J. Am. Chem. Soc. 91 (22): 5970–5977. doi:10.1021/ja01050a008.
  3. ↑ Ball, R. G.; Graham, W. A. G.; Heinekey, D. M.; Hoyano, J. K.; McMaster, A. D.; Mattson, B. M.; Michel, S. T. (1990). "Synthesis and structure of dicarbonylbis(η-pentamethylcyclopentadienyl)diiridium". Inorg. Chem. 29 (10): 2023–2025. doi:10.1021/ic00335a051.
  4. ↑ Ikariya, T.; Blacker, A. J. (2007). "Asymmetric transfer hydrogenation of ketones with bifunctional transition metal-based molecular catalysts". Acc. Chem. Res. 40 (12): 1300–1308. doi:10.1021/ar700134q. PMID   17960897.
  5. ↑ Shimogawa, Ryuichi; Takao, Toshiro; Suzuki, Hiroharu (2017). "Half-sandwich Cyclopentadienyl Iridium Dichloride Monomer Cp‡IrCl2 (Cp‡ = 1,2,4-tri-tert-butylcyclopentadienyl)". Chemistry Letters. 46 (2): 197–199. doi:10.1246/cl.160937.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.