Synthesis and reactivity of triosmium nitrite clusters containing some functionalised amine ligands

Abstract

Reaction of [Os₃(µ-H)(CO)₁₀(µ-η²-NO₂)] 1 with ammonia and some amines [2-phenylethylamine, octadecylamine, 4-tert-butylcyclohexylamine, piperidine-1-ethanamine (pipea) and 1-ethynylcyclohexylamine (echa)] afforded a pair of isomers a and b with general formula [Os₃(µ-H)(CO)₉(µ-η²-NO₂)(NH₂R)], R = H 2a and 2b, CH₂CH₂Ph 3a and 3b, (CH₂)₁₇CH₃ 5a and 5b, (C₆H₁₀)Bu^t-4 6a and 6b, pipea 7a and 7b or echa 10a and 10b. Carbonylation of isomers 3a and 3b afforded [Os₃(µ-H)(CO)₁₀(µ-NHCH₂CH₂Ph)] 4. Thermolysis of 7a and 7b afforded [Os₃(µ-H)(CO)₁₀(µ-pipea – H)] 8 and [Os₃(µ-H)(CO)₉(µ-η²-pipea – H)] 9. Thermolysis of 10a resulted in hydride migration, from the metal core to the unsaturated carbons in the organic moiety, to give [Os₃(CO)₉(µ-η²-NO₂)(echa + H)] 11. All these clusters were fully characterised by solution spectroscopic methods and the solid state structures of 2a, 4, 5a, 7b, 8, 9 and 11 were determined by X-ray crystallography.