The electron-rich metallothiol CpRu(PPh3)2SH (1) has been prepared from the reactions of CpRu(PPh3)2Cl with NaSH and CpRu(PPh3)2H with elemental sulfur. Carbonylation of 1 gives CpRu(PPh3)(CO)SH whereas the carbonylation of CpRu(PPh3)2Cl is thermodynamically unfavorable. Protonation of 1 gives [CpRu(PPh3)2(SH2)]+. Alkylation of 1 gives thiol complexes [CpRu(PPh3)2(RSH)]+ (R = CH3); such complexes were also prepared directly from CpRu(PPh3)2OTf (OTf = CF3SO3) and RSH. The structure of the thiol complex [CpRu(PPh3)2(n-PrSH)]BF4·CH 2Cl2 was determined by X-ray methods. Crystal data: triclinic space group P1, with a = 13.308 (5) Å, b = 14.641 (7) Å, c = 13.205 Å, α = 113.64 (3)°, β = 110.01 (4)°, γ = 84.45 (3)°, V = 2212 (2) Å3, and Z = 2; structure solution and refinement based on 4091 reflections with I > 2.58σ(I) to give R = 0.054. [CpRu(PPh3)2(SH2)]+ reacts reversibly with H2 to give the dihydride [CpRu(PPh3)2H2]+. Analogous results were found for [((2-SC4H3)CH2C5H 4)Ru(PPh3)2]+; the S-bound thiophene ligand can be displaced by H2S, H2, H-, and SH-. [CpRu(PPh3)2(H2S)]+ oxidizes in air to give [CpRu(PPh3)2]2(μ-S2)2+ (2). Salts of 2 are formed in two-electron oxidations of 1 with Ph3CBF4, Cp2Fe+, and I2 as well as electrochemically. A presumed intermediate in this oxidation is [CpRu(PPh3)2]2(μ-S2)+. This mixed-valence compound disproportionates upon addition of HOTf to give 2 and [CpRu(PPh3)2(SH2)]+. The reaction of 1 with sulfur gave ruthenium polysulfides [CpRu(PPh3)]2Sx (x = 4, 6).
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry