Ruthenium(II) Thiol and H₂S Complexes: Synthesis, Characterization, and Thermodynamic Properties

The known, green, five-coordinate species <i>trans</i>-RuCl₂(P–N)­(PPh₃) react with R′SH thiols to give yellow <i>cis</i>-RuCl₂(P–N)­(PPh₃)­(R′SH) products (P–N = <i>o</i>-diphenylphosphino-<i>N</i>,<i>N</i>′-dimethylaniline; R′ = alkyl). The MeSH and EtSH compounds are structurally characterized, with the former being the first reported for a transition metal–MeSH complex, while the thiol complexes with R′ = ^<i>n</i>Pr, ^<i>i</i>Pr, ^<i>n</i>Pn (pentyl), ^<i>n</i>Hx (hexyl), and Bn (benzyl) are synthesized in situ. Other <i>trans</i>-RuX₂(P–N)­(PR₃) complexes (X = Br, I; R = Ph, <i>p</i>-tolyl) are synthesized, and their H₂S adducts, of a type reported earlier by our group, are also prepared. Thermodynamic data are presented for the reversible formation of the MeSH and EtSH complexes and the H₂S analogues. The Ru^IICl₂(P–N)­(PPh₃) complex in solution decomposes under O₂ to form [Ru^IIICl­(P–N)]₂(μ-O)­(μ-Cl)<sub>2