Specific reactivity of SH versus OH functions towards dinuclear arene ruthenium units : synthesis of cationic complexes of the type [(arene)₂Ru₂(SR)₃]⁺

The reaction of [(arene)RuCl₂]₂ (arene=C₆H₆, <i>p</i>-Me—C₆H₄—<i>ⁱ</i>Pr, C₆Me₆) with <i>p</i>-thiocresol, 2-mercaptoethanol and <i>p</i>-mercaptophenol in refluxing ethanol gives the tris-thiolato complexes [(arene) ₂Ru₂(SR)₃]⁺ (R=<i>p</i>-C₆H₄—Me, CH₂CH₂OH, p-C₆H₄OH) which can be isolated as the chloride salts. The remarkable selectivity of (arene)ruthenium units for SH versus OH functions reflects the affinity of ruthenium towards sulfur.