Synthesis, Structures, and Reactions of Coordinatively Unsaturated Trinuclear Ruthenium Polyhydrido Complexes, [{Ru(C5Me5)}3([mu]-H)6](Y) (Y = BF4, CF3SO3, 1/2(SO4), C6H5CO2, CH3CO2, B(C6H5)4, PF6) and [{Ru(C5Me5)}3([mu]-H)3([mu]3-H)2]

• Published in: Bulletin of the Chemical Society of Japan 2005-01, Vol.78 (1), p.67
• Main Authors: Suzuki, Hiroharu, Kakigano, Takeaki, Tada, Ken-ichi, Igarashi, Minoru, Matsubara, Kouki, Inagaki, Akiko, Oshima, Masato, Takao, Toshiro
• Format: Article
• Language: English
• ISSN: 0009-2673; 1348-0634

Cationic triruthenium hexahydrido complexes, [{Ru(C5Me5)}3(μ-H)6](Y) (Y = BF4, CF3SO3, 1/2(SO4), C6H5CO2, CH3CO2), have been synthesized by the reaction of diruthenium tetrahydride [{Ru(C5Me5)}2(μ-H)4] with the corresponding acid, HBF4, CF3CO2H, H2SO4, C6H5CO2H, and CH3CO2H. The trimeric structure of these complexes has been confirmed by a crystallographic study of [{Ru(C5Me5)}3(μ-H)6](PF6). The treatment of [{Ru(C5Me5)}3(μ-H)6](Y) with CH3ONa in methanol selectively afforded a neutral trinuclear pentahydrido complex, [{Ru(C5Me5)}3(μ-H)3(μ3-H)2], which underwent an intermolecular H/D exchange reaction with benzene-d6, toluene-d8, or o-xylene-d10 to give [{Ru(C5Me5)}3(μ-D)3(μ3-D)2] as the result of arene C-H bond activation via an η2-arene intermediate complex. A cationic hydrido complex, [{Ru(C5Me5)}3(μ-H)6](Y), having a carboxylate as a counter anion was equilibrated with [{Ru(C5Me5)}3(μ-H)3(μ3-H)2] in solution, and the equilibrium constant depended on the counter anion. An X-ray diffraction study showed that [{Ru(C5Me5)}3(μ-H)3(μ3-H)2] has a triangular reaction field surrounded by three C5Me5 ligands. The reaction of [{Ru(C5Me5)}3(μ-H)3(μ3-H)2] with 1 equiv of O2 proceeded with the retention of the Ru3 framework to yield an 80/20 mixture of a mono-μ3-oxo complex [{Ru(C5Me5)}3(μ-H)3(μ3-O)] and a di-μ3-oxo complex [{Ru(C5Me5)}3(μ-H)3(μ3-O)2]. A novel trinuclear μ3-iodo-tetra-μ-hydrido complex, [{Ru(C5Me5)}3(μ3-H)(μ-H)3(μ3-I)] was formed upon the treatment of [{Ru(C5Me5)}3(μ-H)3(μ3-H)2] with 1 equiv of CH3I in tetrahydrofuran. The treatment of [{Ru(C5Me5)}3(μ-H)3(μ3-H)2] with carbon monoxide generated a paramagnetic trinuclear tetracarbonyl complex, [{Ru(C5Me5)}3(μ-CO)3(μ3-CO)].