Ruthenium pentacarbonyl

Ruthenium pentacarbonyl is the ruthenium compound with the formula Ru(CO)₅. It is a colorless, light-sensitive liquid that readily decarbonylates upon standing at room temperature. It is of academic interest as an intermediate for the synthesis of metal carbonyl complexes.^[2]

Ruthenium pentacarbonyl

Names
Other names Pentacarbonylruthenium
Identifiers
CAS Number	16406-48-7
3D model (JSmol)	Interactive image
ChemSpider	65793305
PubChem CID	11053793
InChI InChI=1S/5CO.Ru/c5*1-2; Key: UMIQWFOHGPOVPP-UHFFFAOYSA-N
SMILES C(=O)=[Ru](=C=O)(=C=O)(=C=O)=C=O
Properties
Chemical formula	Ru(CO)5
Molar mass	241.12
Appearance	colorless liquid
Melting point	−16–17[1] °C (3–63 °F; 257–290 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

Ru(CO)₅ was originally prepared by carbonylation of ruthenium salts in the presence of a reducing agent.^[3] A more recent preparation involves photolysis of triruthenium dodecacarbonyl in the presence of carbon monoxide:^[2]

Ru₃(CO)₁₂ + 3 CO ⇌ 3 Ru(CO)₅

It is characterized by two intense ν_CO bands in the IR spectrum at 2038 and 2003 cm⁻¹ (hexane solution).^[2]

Comparisons of M(CO)5 (M = Fe, Ru, Os)

Whereas Fe(CO)₅ is completely robust at room temperature, samples of Ru(CO)₅ are typically reddish owing to contamination by Ru₃(CO)₁₂. The conversion is rapid in solution. Os(CO)₅ requires heating to 80 °C to effect conversion to triosmium dodecacarbonyl.^[1]