Half-Sandwich Ruthenium Phosphine Complexes with Sulfur-Donor Ligands. X-ray Crystal Structures of [Cp*RuH(SH)(PEt₃)₂][BPh₄] and [Cp*Ru(S₂COiPr)(PEt₃)]

The complexes [CpRuCl(PEt3)2] (1) and [CpRuCl(PMeiPr2)(PPh3)] (2) react with H2S in EtOH in the presence of NaBPh4 furnishing the green persulfide derivatives [{CpRu(L)}2(μ-S2)][BPh4]2 (L = (PEt3)2, (PMeiPr2)(PPh3)), which were also obtained by reaction of 1 or 2 with elemental sulfur and NaBPh4 in MeOH. At variance with this, the reaction of [Cp*RuCl(PEt3)2] (3) with H2S in EtOH afforded the RuIV hydrido-metallothiol [Cp*RuH(SH)(PEt3)2][BPh4], which has been structurally characterized, derived from the oxidative addition of SH2 to the electron−rich RuII moiety {[Cp*Ru(PEt3)2]+}. This compound is oxidized to yield the persulfide complex [{Cp*Ru(PEt3)2}2(μ-S2)][BPh4]2, which was also obtained by reaction of 3 with elemental sulfur. The reaction of 1, 2, and 3 with 2-mercapto-pyridine (HSPy) in EtOH yielded cationic complexes in which HSPy is tautomerized to its 1H-pyridine-thione form as inferred from spectral data. Compound 1 reacts with potassium alkyl-xanthates KS2COR (R = Me, Et, iPr) yielding compounds of the type [CpRu(η1-S2COR)(PEt3)2], whereas the reaction of 2 and 3 led respectively to the complexes [CpRu(η2-S2COR)(PMeiPr2)] and [Cp*Ru(η2-S2COR)(PEt3)], which contain one bidentate xanthate and one phosphine. The X-ray crystal structure of [Cp*Ru(S2COiPr)(PEt3)] was determined. In analogous fashion, the reaction of 1 with sodium diethyldithiocarbamate yielded [CpRu(η1-S2CNEt2)(PEt3)2], whereas 2 and 3 afforded the corresponding derivatives [CpRu(η2-S2CNEt2)(PMeiPr2)] and [Cp*Ru(η2-S2CNEt2)(PEt3)].