From oxide to a new type of molecular tungsten compound: formation of bitetrahedral cluster complexes [{W6(μ4-O)2(μ3-CCN)4}(CN)16]10− and [{W6(μ4-O)2(μ3-As)4}(CN)16]10−

Abstract

Tungsten trioxide has been found to be a convenient precursor for the synthesis of metal cluster compounds with new types of cluster cores. The reaction between WO₃ and KCN led to the formation of the cluster complex [{W₆(μ₄-O)₂(μ₃-CCN)₄}(CN)₁₆]¹⁰⁻. Unexpectedly, it includes the fully deprotonated form of acetonitrile, the CCN³⁻ anion, as a μ₃-bridging ligand coordinated to the trigonal faces of the bitetrahedral W₆ metallocluster. A similar complex [{W₆(μ₄-O)₂(μ₃-As)₄}(CN)₁₆]¹⁰⁻ containing μ₃-As³⁻ ligands instead of μ₃-CCN³⁻ ones has been synthesized by the reaction between WO₃, As and KCN.