Some reactions of dodecacarbonyltriosmium

Abstract

Reaction between Os₃(CO)₁₂ and but-2-yne gives two complexes tentatively identified as tricarbonyltetramethylcyclopentadienoneosmium and the binuclear complex (MeC₂Me)₂Os₂(CO)₆. Cyclo-octatetraene reacts with the carbonyl to give C₈H₈Os(CO)₃, with the hydrocarbon bonded to the metal via a π-allyl group and a carbon–metal σ-bond. On warming, the complex isomerises to a 1,3-diene complex, which exhibits valence tautomerism. This compound reacts with (MeO)₃P to give trans-[(MeO)₃P]₂Os(CO)₃.

With MePPh₂, the carbonyl gives [(MePPh₂)Os(CO)₃]₃. Trimethylsilane and Os₃(CO)₁₂ form trans-(Me₃Si)₂Os(CO)₄, in which the Si–Os bonds can be cleaved with hydrogen chloride to give trans-Os(CO)₄Cl₂. A variety of other halogenocarbonyls resulted from reactions between the carbonyl and CF₃I, iodine, or HCl.