Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium is the organoruthenium

half-sandwich compound Half sandwich compounds, also known as piano stool complexes, are organometallic complexes that feature a cyclic polyhapto ligand bound to an MLn center, where L is a unidentate ligand. Thousands of such complexes are known. Well-known examples in ...

with formula RuCl(PPh₃)₂(C₅H₅). It as an air-stable orange crystalline solid that is used in a variety of

organometallic Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and so ...

synthetic and catalytic transformations. The compound has idealized C_s symmetry. It is soluble in

chloroform Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to ...

dichloromethane Dichloromethane (DCM or methylene chloride, methylene bichloride) is an organochlorine compound with the formula . This colorless, volatile liquid with a chloroform-like, sweet odour is widely used as a solvent. Although it is not miscible with ...

, 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 Cyclopentadiene is an organic compound with the chemical formula, formula C5H6.LeRoy H. Scharpen and Victor W. Laurie (1965): "Structure of cyclopentadiene". ''The Journal of Chemical Physics'', volume 43, issue 8, pages 2765-2766. It is often ab ...

. : RuCl₂(PPh₃)₃ + C₅H₆ → RuCl(PPh₃)₃(C₅H₅) + HCl It is prepared by heating a mixture of

ruthenium(III) chloride Ruthenium(III) chloride is the chemical compound with the formula RuCl3. "Ruthenium(III) chloride" more commonly refers to the hydrate RuCl3·''x''H2O. Both the anhydrous and hydrated species are dark brown or black solids. The hydrate, with a va ...

, triphenylphosphine, and

in ethanol.

Reactions

Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) undergoes a variety of reactions often by involving substitution of the chloride. With phenylacetylene it gives the phenyl vinylidene complex: : (C₅H₅)(PPh₃)₂RuCl + HC₂Ph + NH₄ F₆ → u(C:CHPh)(PPh₃)₂(C₅H₅)F₆+ NH₄Cl Displacement of one PPh₃ by carbon monoxide affords a chiral compound. :(C₅H₅)(PPh₃)₂RuCl + CO → (C₅H₅)(PPh₃)(CO)RuCl + PPh₃ The compound can also be converted into the hydride: :(C₅H₅)(PPh₃)₂RuCl + NaOMe → (C₅H₅)(PPh₃)₂RuH + NaCl + CH₂O A related complex is tris(acetonitrile)cyclopentadienylruthenium hexafluorophosphate, which has three labile MeCN

ligands In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electro ...

Applications

Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) serves as a catalyst for a variety of specialized reactions. For example, in the presence of NH₄PF₆ it catalyzes the

isomerisation In chemistry, isomerization or isomerisation is the process in which a molecule, polyatomic ion or molecular fragment is transformed into an isomer with a different chemical structure. Enolization is an example of isomerization, as is tautomeriz ...

of allylic alcohols to the corresponding saturated carbonyls.Murahashi, Shun-Ichi. "Ruthenium in Organic Synthesis" (2006) Wiley-VCH: Weinheim.

References

{{Ruthenium compounds Organoruthenium compounds Triphenylphosphine complexes Cyclopentadienyl complexes Chloro complexes Ruthenium(II) compounds