Synthesis and structural characterisation of new cationic dinuclear ruthenium(II) thiolato complexes of the type [Ru₂(η⁶-arene)₂(μ-<i>p</i>-S–C₆H₄–Br)₃]⁺

Dinuclear dichloro complexes [Ru(C₆H₆)Cl₂]₂, [Ru(p-MeC₆H₄<i>ⁱ</i>Pr)Cl₂]₂, [Ru(1,2,4,5-C₆H₂Me₄)Cl₂]₂, and [Ru(C₆Me₆)Cl₂]₂ react in ethanol with <i>p</i>-bromothiophenol to give the corresponding cationic complexes [Ru₂(C₆H₆)₂(<i>p</i>-S–C₆H₄–Br)₃]</sup>+</sup> (<b>1</b>), [Ru₂(<i>p</i>-MeC₆H₄<i>ⁱ</i>Pr)₂(<i>p</i>-S–C₆H₄–Br) ₃]⁺ (<b>2</b>), [Ru₂(1,2,4,5-C₆H₂Me₄)₂(<i>p</i>-S–C₆H₄–Br)₃]⁺ (<b>3</b>), and [Ru₂(C₆Me₆)₂(<i>p</i>-S–C₆H₄–Br)₃]⁺ (<b>4</b>), which can be isolated in quantitative yield as their chloride salts. X-ray structure analysis of these complexes shows that the nature of the arene ligand influences the folding of the <i>p</i>-S–C₆H₄–Br units. In <b>1</b>, where the less hindered arene ligand is present, the three phenyl rings of the thiolato units are not constrained to a coplanar arrangement, whereas in <b>4</b> the C₆Me₆ forces the three phenyl rings to be in perfect planarity. Complexes <b>2</b> and <b>3</b> show an intermediary arrangement.