High nuclearity clusters of osmium and ruthenium containing the [Au₂(Ph₂PCH₂PPh₂)]²⁺ cation; The X-ray structures of [Os₄H₄(CO)₁₁Au₂(Ph ₂PCH₂PPh₂)]

Treatment of [Os₄H₄(CO)₁₁]^2-, [Os₁₀C(CO)₂₄]^2- and [Ru₁₀C(CO)₂₄]^2- with [Au₂(Ph₂PCH₂PPh₂)Cl₂] in the presence of an excess of TIPF₆, gave [Os₄H₄(CO)₁₁(Au₂Ph ₂PCH₂PPh₂)] 1, [Os₁₀C(CO)₂₄(Au₂Ph₂PCH ₂PPh₂)] 2 and [Ru₁₀C(CO)₂₄(Au₂Ph₂PCH ₂PPh₂)] 3, respectively, all of which were obtained in high yield. The structures of the clusters l and 3 have been established by X-ray crystallography, both exhibiting novel coordination modes of the bidentate gold fragments. Cluster 1 contains a tetrahedral Os₄ core with one of the Au atoms of the Au₂(Ph₂PCH₂PPh₂) ligand bridging an edge of the tetrahedron, and the second Au atom coordinated to a third Os atom. In 3 the two Au atoms of the Au₂(Ph₂PCH₂PPh₂) ligand cap two adjacent, vertex sharing, triangular faces of the Ru₁₀ tetracapped octahedral core.