Synthesis and molecular structure of trinuclear mixed-metal cluster cations containing arene and hydrido ligands

The mixed-metal trinuclear cluster cations [H₃Ru₂(C₆Me₆)2Os(C₆H₆)(O)]⁺ (<b>1</b>), [H₃Ru₂ (1,2,4,5-C₆H₂Me₄)2Os(p-MeC₆H₄ⁱPr)(O)]⁺ (<b>2</b>) and [H₃Ru₂ (1,2,4,5-C₆H₂Me₄)2Os(C₆H₆)(O)]⁺ (<b>3</b>) have been synthesised from the corresponding dinuclear precursors [H₃Ru₂(arene)₂]⁺ and the corresponding mononuclear complexes [Os(arene)(H₂O) ₃]²⁺, isolated and characterised as the tetrafluoroborate and hexafluorophosphate salts. The cations <b>1</b>, <b>2</b> and <b>3</b> are heteronuclear analogues of the cluster cation [H₃Ru₃(C₆H₆)(C₆Me₆)₂ (O)]⁺ that possesses a homonuclear metallic core. The single-crystal X-ray structure analyses of [<b>1</b>][BF₄], [<b>2</b>][PF₆] and [<b>3</b>][PF₆] reveal an equiangular metal triangle despite the presence of an osmium atom in the metallic core.