Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium

CpRuCl(PPh3)2
Identifiers
CAS number	32993-05-8
Properties
Molecular formula	C41H35ClP2Ru
Molar mass	726.19 g/mol
Appearance	Orange solid
Melting point	135°C (408 K)
Solubility in water	Insoluble
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Infobox references

Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium is the organoruthenium half-sandwich compound with formula RuCl(PPh₃)₂(C₅H₅). It as an air-stable orange crystalline solid that is used in a variety of organometallic synthetic and catalytic transformations.

Structure and Properties

The compound has idealized C_s symmetry. It is soluble in chloroform, dichloromethane, and acetone.

Preparation

Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium was first reported in 1969 when it was prepared by reacting dichlorotris(triphenylphosphine)ruthenium(II) with cyclopentadiene.^[1]

RuCl₂(PPh₃)₃ + C₅H₆ → RuCl(PPh₃)₃(C₅H₅) + HCl

It is easily prepared from ruthenium(III) chloride, triphenylphosphine, and cyclopentadiene in ethanol.^[2]

Reactions

Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) undergoes a variety of substitution reactions often by involving substitution of the chloride. With phenylacetylene it gives the phenyl vinylidene complex.

(C₅H₅)(PPh₃)₂RuCl + HC₂Ph + NH₄[PF₆] → [Ru(C:CHPh)(PPh₃)₂(C₅H₅)][PF₆] + NH₄Cl

Displacement of PPh₃ by carbon monoxide affords a chiral compound.^[3]

(C₅H₅)(PPh₃)₂RuCl + CO → (C₅H₅)(PPh₃)(CO)RuCl + PPh₃

The compound can also be converted into the hydride.^[4]

(C₅H₅)(PPh₃)₂RuCl + NaOMe → (C₅H₅)(PPh₃)₂RuH + NaCl + CH₂O

Applications

Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) serves as a catalyst for a variety of reactions. For example, in the presence of NH₄PF₆ it catalyzes the isomerisation of allylic alcohols to the corresponding saturated carbonyls.^[5]

References

1. ^ Gilbert, J.; Wilkinson, G. (1969). "New Complexes of Ruthenium(II) with Triphenylphosphine and other Ligands". J. Chem. Soc.: 1749. doi:10.1039/J19690001749. 
2. ^ Bruce, M., Hamiester, C., Swincer, A., Wallis, R., and Ittel, S. (1982). “Some -Cyclopentadienylruthenium(II) Complexes Containing Triphenylphosphine.” Inorganic Syntheses (1982). 78-82. DOI: 10.1002/9780470132524
3. ^ Blackmore, T., Bruce, M., and Stone, F. (1971). "New Cyclopentadienyltuthenium Complexes". J. Chem. Soc., A: 2376–2382. doi:10.1039/J19710002376. 
4. ^ Wilczewski, T., Bochenska, M., and Biernat, J. (1981). "Cyclobentadienyl-Ruthenium Complexes". J. Organomet. Chem. 215: 87. doi:10.1016/S0022-328X(00)84619-7. 
5. ^ Murahashi, Shun-Ichi. “Ruthenium in Organic Synthesis” (2006) Wiley-VCH: Weinheim. ISBN 978-3-527-30692-3