Rotation of the acetylide ligand on the triangular face of tungsten-diruthenium clusters. Crystal structure and solution dynamics of LWM 2(CO) 8(CCPh), L = C 5H 5, C 5Me 5 and M = Os, Ru

Abstract

Reaction of CpW(CO) 3CCPh with OS 3(CO) 10(CH 3CN) 2 or Ru 3(CO) 12 in refluxing toluene gives trinuclear mixed-metal acetylide clusters, CpWOs 2(CO) 8(CPh) ( 1) and CpWRu 2(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 WRu 2 triangle.