(Cymene)ruthenium dichloride dimer

(cymene)ruthenium dichloride dimer

Names
Other names Dichloro(p-cymene)ruthenium(II) dimer
Identifiers
CAS Number	52462-29-0
ChemSpider	8297222
Jmol interactive 3D	Image Image
InChI InChI=1S/2C10H14.4ClH.2Ru/c2*1-8(2)10-6-4-9(3)5-7-10;;;;;;/h2*4-8H,1-3H3;4*1H;;/q;;;;;;2*+2/p-4 Key: LAXRNWSASWOFOT-UHFFFAOYSA-J InChI=1/2C10H14.4ClH.2Ru/c2*1-8(2)10-6-4-9(3)5-7-10;;;;;;/h2*4-8H,1-3H3;4*1H;;/q;;;;;;2*+2/p-4 Key: LAXRNWSASWOFOT-XBHQNQODAM
SMILES [Ru+2].[Ru+2].[Cl-].[Cl-].[Cl-].[Cl-].c1cc(ccc1C(C)C)C.c1cc(ccc1C(C)C)C Cc1ccc(cc1)C(C)C.Cc1ccc(cc1)C(C)C.[Cl-].[Cl-].[Cl-].[Cl-].[Ru+2].[Ru+2]
Properties
Chemical formula	C20H28Cl4Ru2
Molar mass	612.38 g·mol^−1
Appearance	Red solid
Melting point	247 to 250 °C (477 to 482 °F; 520 to 523 K) (decomposes)
Solubility in water	Slightly, with hydrolysis
Except where otherwise noted, data are 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 74–78.
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