Synthesis of a Cyclic Co₂Sn₂ Cluster Using a Co^– Synthon

[Ar′SnCo]₂ (1, Ar′ = C₆H₃-2,6{C₆H₃-2,6-ⁱPr₂}₂), a rare metal–metal bonded cobalt–tin cluster with low-coordinate tin atoms, was prepared by the reaction of [K(thf)_0.2][Co(1,5-cod)₂] (cod = 1,5-cyclooctadiene) with [Ar′Sn(μ-Cl)]₂. This reaction illustrates a promising synthetic strategy to access uncommon metal clusters. The structure of 1 features a rhomboidal Co₂Sn₂ core with strong metal–metal bonds between tin and cobalt and a weaker tin–tin interaction. Reaction of 1 with white phosphorus afforded [Ar′₂Sn₂Co₂P₄] (2), the first molecular cluster compound containing phosphorus, cobalt and tin.