Nonanuclear Ruthenium Carbonyl Cluster Complexes with a Novel Metallic Skeleton:  Pentagonal Bipyramid with Two Equatorial Edges Spanned by Metal Atoms

The nonanuclear cluster complexes [Ru₉(μ-H)₂(μ₄-κ²-ampy)₄(CO)₁₇] and [Ru₉(μ₃-H)(μ-H)(μ₄-κ²-ampy)₃(CO)₁₈] (ampy = 2-imido-6-methylpyridine) have been prepared by heating [Ru₆(μ₃-H)₂(μ₅-κ²-ampy)(μ-CO)₂(CO)₁₄] in undecane at reflux temperature. Both compounds feature a novel metallic skeleton that can be described as a pentagonal bipyramid with two equatorial edges spanned by metal atoms. In both cases, the ampy ligands are attached to edge-bridging Ru atoms through the pyridine N atoms, while their imido N atoms cap metallic triangles formed by the metal atoms of one of the metal-bridged edges and one of the apical metal atoms.