The enneacarbonyls of ruthenium and osmium

Abstract

The ultraviolet irradiation of n-heptane solutions of the pentacarbonyls of ruthenium and osmium at –40 °C has been studied. In the case of [Os(CO)₅], the new carbonyl compound [Os₂(CO)₉] has been isolated and is found to decompose only slowly in solution. The product of the low-temperature irradiation of [Ru(CO)₅], which has only been partially characterized as [Ru₂(CO)₉], is extremely unstable in both the solid state and in solution at room temperature. The decompositions of [Os₂(CO)₉] and [Ru₂(CO)₉] in solution have been studied and are discussed. The reaction of [Os₂(CO)₉] with hydrogen gives the known dihydride [Os₂(CO)₈H₂]. With PPh₃, the products are [Os(CO)₄(PPh₃)] and [Os₂(CO)₈H₂] but with PEt₃ only [Os₂(CO)₈H₂] is formed. Infrared and mass spectra for [Ru₂(CO)₉] and [Os₂(CO)₉] are reported and discussed.