Skeletal Rearrangement of a C2 Unit on a Triruthenium Cluster. Synthesis of μ-Ethylidene, μ3-Ethylidyne, and μ3-Vinylidene Complexes by the Reaction of {CpRu(μ-H)}3(μ3-H)2 with Acetylene

• Published in: Organometallics Vol. 21; no. 24; pp. 5190 - 5203
• Main Authors: Takao, Toshiro, Takemori, Toshifumi, Moriya, Makoto, Suzuki, Hiroharu
• Format: Journal Article
• Language: English
• Published: American Chemical Society 25.11.2002
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om020502g

Reaction of the triruthenium pentahydride complex {Cp*Ru(μ-H)}3(μ3-H)2 (1; Cp* = η5-C5Me5) with acetylene was investigated, in which the μ3-ethylidene−μ3-η2(∥)-ethyne complex {Cp*Ru(μ-H)}3(μ-CMeH){μ3-η2(∥)-CHCH} (2) was produced via formation of the intermediary bis(μ-vinyl) complex {Cp*Ru(μ-H)}3(μ-η1:η2-CHCH2)2 (3). An α-C−H bond of the μ-ethylidene ligand of 2 underwent oxidative addition upon thermolysis to yield the μ3-ethylidyne−μ3-η2(∥)-ethyne complex (Cp*Ru)3(μ-H)2(μ3-CCH3){μ3-η2(∥)-CHCH} (5), which showed fluxional behavior of both the μ3-ethyne and the hydride ligands. Further C−H bond cleavage of the μ3-ethylidyne ligand, affording the μ-vinylidene−μ3-η2(∥)-ethyne complex (Cp*Ru)3(μ-H)(μ3-CCH2){μ3-η2(∥)-CHCH} (6), was also investigated. Treatment of 5 with an excess amount of acetylene resulted in C−C bond formation at the Ru3 core, and the μ3-ethylidyne−μ3-η3-diruthenaallyl complex (Cp*Ru)3{μ3-η1:η3:η1-C(H)C(H)CCH3}(μ3-CCH3)(μ-H) (7) was obtained. The molecular structures of 5 and 7 were determined by single-crystal X-ray diffraction studies.