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((PMePr2)-Pr-i)(PPh3)] (2) react with H2S in EtOH in the presence of NaBPh4 furnishing the green persulfide derivatives [{CpRu(L)}(2)(mu-S-2)][BPh4](2) (L = (PEt3)(2), ((PMePr2)-Pr-i)(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 Ru-IV hydrido-metallothiol [Cp*RuH(SH)(PEt3)(2)][BPh4], which has been structurally characterized, derived from the oxidative addition of SH2 to the electron-rich Ru-II moiety {[Cp*Ru(PEt3)(2)](+)}. This compound is oxidized to yield the persulfide complex [{Cp*Ru(PEt3)(2)}(2)(mu-S-2)][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, Pr-i) yielding compounds of the type [CpRu(eta(1)-S2COR)(PEt3)(2)], whereas the reaction of 2 and 3 led respectively to the complexes [CpRu(eta(2)-S2COR)((PMePr2)-Pr-i)] and [Cp*Ru(eta(2)-S2COR)(PEt3)], which contain one bidentate xanthate and one phosphine. The X-ray crystal structure of [Cp*Ru((S2COPr)-Pr-i)(PEt3)] was determined. In analogous fashion, the reaction of 1 with sodium diethyldithiocarbamate yielded [CpRu(eta(1)-S2CNEt2)(PEt3)(2)], whereas 2 and 3 afforded the corresponding derivatives [CpRu(eta(2)-S2CNEt2)((PMePr2)-Pr-i)] and [Cp*Ru(eta(2)-S2CNEt2)(PEt3)].