Misplaced Pages

Pentamethylcyclopentadienyl iridium dichloride dimer

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Pentamethylcyclopentadienyl iridium dichloride dimer
Names
IUPAC name Di-μ-chloro-bis
Other names Dichloro(pentamethylcyclopentadienyl)iridium(III)
Identifiers
CAS Number
3D model (JSmol)
ECHA InfoCard 100.205.779 Edit this at Wikidata
PubChem CID
UNII
InChI
  • InChI=1S/2C10H16.4ClH.2Ir/c2*1-6-7(2)9(4)10(5)8(6)3;;;;;;/h2*6H,1-5H3;4*1H;;/p-4Key: PGQVOTGCKISIMD-UHFFFAOYSA-J
SMILES
  • c1(C)=c(C)c(C)=c(C)c1(C)(Cl)(Cl1)Cl(Cl)1C1(C)C(C)=C(C)C(C)=C1C
Properties
Chemical formula C20H30Cl4Ir2
Molar mass 796.71 g/mol
Appearance orange solid
Melting point >230 °C
Solubility in water Dichloromethane, Chloroform
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). checkY verify (what is  ?) Infobox references
Chemical compound

Pentamethylcyclopentadienyl iridium dichloride dimer is an organometallic compound with the formula 2, commonly abbreviated 2 This bright orange air-stable diamagnetic solid is a reagent in organometallic chemistry.

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. More conveniently, the compound is prepared by the reaction of hydrated iridium trichloride and pentamethylcyclopentadiene in hot methanol, from which the product precipitates

2 Cp*H + 2 IrCl3(H2O)3 → 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 and . The chloride ligands can also be replaced by other anions such as carboxylates, nitrite, and azide.

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

2 is a precursor to catalysts for the asymmetric transfer hydrogenation of ketones.

Related compounds

References

  1. ^ White, C.; Yates, A.; Maitlis, P. M. (1992). "(η -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 CpIrCl2 (Cp = 1,2,4-tri-tert-butylcyclopentadienyl)". Chemistry Letters. 46 (2): 197–199. doi:10.1246/cl.160937.
Categories: