Cationic transition-metal complexes. Part I. Synthesis and reactions of bis(diene)-rhodium and -iridium tetrafluoroborates

Abstract

Reaction of [M(dien)(acac)](M = Rh or Ir; diene = 1,5-C₈H₁₂ or bicyclo[2,2,1]heptadiene) with Ph₃C⁺BF₄^– in the presence of an excess of diene affords [M(diene)₂]⁺BF₄^–, from which diene is readily displaced by acetonitrile to form [M(diene)(CH₃CN)₂]⁺BF₄^–. Reaction of [M(diene)(CH₃CN)₂]⁺BF₄^– with phosphines and bipyridyl are described; complexes of the type [M(diene)L₂]⁺BF₄^– and [ML₄]⁺BF₄^– being formed depending on the nucleophilicity of the ligand L. Reaction of [M(1,5-C₈H₁₂)₂]⁺BF₄^– with sodium iodide in acetone affords [M(1,5-C₈H₁₂)I]₂. Methanol reacts with [Ir(1,5-C₈H₁₂)₂]⁺BF₄^– in the presence of sodium carbonate to give [Ir(1,5-C₈H₁₂)OMe]₂; a mixture of syn- and anti-isomers.