The reaction of diphenyl ditelluride with triosmium clusters

Abstract

The reaction of Ph₂Te₂ with Os₃(CO)₁₀(CH₃CN)₂ at room temperature gave the cluster Os₃(CO)₁₀(μ-TePh)₂1, in which one TePh bridges an “open” Os⋯Os edge and another bridges an Os–Os bond. Thermolysis of 1 in refluxing cyclohexane led to isomerisation of 1 to 2, in which both TePh moieties bridge the same “open” Os⋯Os edge; thermolysis of 2 in refluxing octane led to the cluster Os₃(CO)₉(μ₃-Te)₂3. The reaction of Ph₂Te₂ with Os₃(μ-H)₂(CO)₁₀, on the other hand, resulted in a complex mixture of products among which were the clusters Os₃H₂(CO)₁₀(μ-TePh)₂4 and Os₃(μ-H)(CO)₁₀(μ-TePh) 5; cluster 5 was also obtained in moderate yield from the reaction with [Os₃(μ-H)(CO)₁₀(μ-CO)]⁻. Cluster 4 comprises a four-membered Os₂Te₂ ring, with an HOs(CO)₄ fragment attached to one of the osmium atoms; it decomposed on silica gel to afford the dinuclear compound [OsH(CO)₃(TePh)]₂6. The clusters 1–6 have all been characterised by single crystal X-ray crystallography.