Concurrent Rearrangement of Phenylimido and Alkenyl Ligands on a WRu₂ Metal Triangle

Thermolysis of the phenylimido cluster [WRu₂(η-C₅Me₅)(CO)₇(μ₃-NPh)(CF₃CCHCF₃)] 1b in refluxing toluene yielded a hydrido-alkyne complex [WRu₂(η-C₅Me₅)(CO)₆H(μ-NPh){C₂(CF₃)₂}] 4 via CO elimination and alkenyl C-H activation. Treatment of 4 with CO in refluxing toluene induced the formation of a second alkenyl complex [WRu₂(η-C₅Me₅)(CO)₇(μ-NPh)(CF₃CCHCF₃)] 2b containing a doubly bridging imido ligand and face-bridging alkenyl ligand. This transformation between 4 and 2b is reversible since complex 4 can be regenerated by thermolysis of 2b in toluene. Complexes 4 and 2b were also examined by single-crystal X-ray diffraction. Crystal data for 4: triclinic space group PĪ; a = 10.332(1), b = 17.296(4), c = 18.351(2) Å, α = 110.81(1), β = 106.31(1), γ = 92.46(2)°, Z = 4; final R = 0.026, R' = 0.024 for 6445 reflections with I > 2σ(I). Crystal data for 2b: monoclinic, space group P2₁/n; a = 11.398(3), b = 22.965(6), c = 11.670(3) Å, β = 99.78(2)°, Z = 4; final R = 0.025, R′ = 0.024 for 3526 reflections with I > 2σ(I).