Pentacarbonyl ruthenium is an organic ruthenium compound having the formula Ru(CO)5. It is a colorless, light-sensitive liquid that is easily decarbonylated when allowed to stand at room temperature. It is of academic significance as an intermediate for the synthesis of metal carbonyl complexes.
Pentacarbonyl ruthenium point -22°C. Insoluble in water, soluble in organic solvents. Volatile, it is difficult to produce pure products. It is unstable and easily generates tridecacarbonyl tris[Ru3·(CO)12]. Used as an oxidation catalyst.
The existence of pentacarbonylruthenium and pentacarbonylosmium has been confirmed and their infrared spectra in the carbonyl stretching region have been measured. The two carbonyls have two infrared-active CO stretching vibrations. This suggests a trigonal-bipyramidal configuration of symmetry D3h. The reactions of the two pentacarbonyls with halogens have also been investigated. Pentacarbonylruthenium gives dihalogenotetracarbonyls of the formula RuX2(CO)4 (X = Br, I) as slightly colored solids, sublimable in vacuo. The infrared spectra suggest a cis octahedral configuration in solution for the dihalogeno complexes.