Synthesis of a Cyclic Co(2)Sn(2) Cluster Using a Co(–) Synthon

[Image: see text] [Ar′SnCo](2) (1, Ar′ = C(6)H(3)-2,6{C(6)H(3)-2,6-(i)Pr(2)}(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 Co(2)Sn(2) core with strong metal–metal bonds between tin and cobalt and a weaker tin–tin interaction. Reaction of 1 with white phosphorus afforded [Ar′(2)Sn(2)Co(2)P(4)] (2), the first molecular cluster compound containing phosphorus, cobalt and tin.