ROTATION OF THE ACETYLIDE LIGAND ON THE TRIANGULAR FACE OF TUNGSTEN-DIRUTHENIUM CLUSTERS. CRYSTAL STRUCTURE AND SOLUTION DYNAMICS OF LWM₂(CO)₈(CCPh), L = C₅H₅, C₅Me₅ AND M = Os, Ru

Reaction of CpW(CO)₃–C≡CPh with OS₃(CO)₁₀(CH₃CN)₂ or Ru₃(CO)₁₂ in refluxing toluene gives trinuclear mixed-metal acetylide clusters, CpWOs₂(CO)₈(C≡CPh) (1) and CpWRu₂(CO)₈(C≡CPh) (3); the acetylide ligands of these two complexes are related to each other by a 120° rotation as indicated by X-ray diffraction studies. In solution, the variable temperature ¹H and ¹³C NMR spectra suggest that the acetylide ligand of 3 undergoes a 360° rotation on the face of the WRu₂ triangle.