(Cymene)ruthenium dichloride dimer

(cymene)ruthenium dichloride dimer
Names
Other names
Dichloro(p-cymene)ruthenium(II) dimer
Identifiers
52462-29-0 Yes
ChemSpider 8297222 Yes
Jmol-3D images Image
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Properties
Molecular formula
C20H28Cl4Ru2
Molar mass 612.39 g·mol−1
Appearance Red solid
Melting point 247 to 250 °C (477 to 482 °F; 520 to 523 K) (decomposes)
Slightly, with hydrolysis
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

(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.

Preparation and reactions

The dimer is prepared by the reaction of the phellandrene with hydrated ruthenium trichloride.[1] Upon heating, [(cymene)RuCl2]2 undergoes exchange with other arenes, releasing free p-cymene. This dimeric molecule cleaves easily in the presence of Lewis bases to give monomeric adducts:

[(cymene)RuCl2]2 + 2 PPh3 → 2 (cymene)RuCl2(PPh3)

Such monomers adopt pseudo-octahedral piano-stool structures.

Treatment of [(cymene)RuCl2]2 with the chelating anionic ligand precursor TsDPENH gives (cymene)Ru(TsDPEN-H), a catalyst for asymmetric transfer hydrogenation.[2]

New catalysts

[(cymene)RuCl2]2 is also used to prepare catalysts (by monomerization with dppf) used in borrowing hydrogen catalysis,[3] a catalytic reaction that is based on the activation of alcohols towards nucleophilic attacks.

References

  1. Bennett, M. A.; Huang, T. N.; Matheson, T. W. , Smith, A. K. "(η6-Hexamethylbenzene)ruthenium Complexes", Inorganic Syntheses, 1982, volume 21, pages 74–8.
  2. Takao Ikariya, Shohei Hashiguchi, Kunihiko Murata, and Ryōji Noyori (2005). "Preparation of Optically Active (R,R)-Hydrobenzoin from Benzoin or Benzil". Org. Synth.: 10.
  3. Hamid et al.; Advanced Synthesis & Catalysis Volume 349, Issue 10, pages 1555–1575, July 2, 2007; doi:10.1002/adsc.200600638