Incorporation of trialkylsilyl and trialkylstannyl groups into ruthenium carbonyl clusters. Carbonyl substitution versus trialkylsilane or trialkylstannane elimination in these clusters

Article abstract of DOI:10.1021/om00046a036

The clusters [Ru₃(μ-H)(μ₃,η²-ampy)(PPh ₃)_n(CO)_9-n] (n = 0 (1), 1 (2), 2 (3); Hampy = 2-amino-6-methylpyridine) react with HSiEt₃ to give the oxidative substitution products [Ru₃(μ-H)₂(μ₃,η ²-ampy)-(SiEt₃)(PPh₃)_n(CO) _8-n] (n = 0 (4a), 1 (5a), 2 (6a)). Similar reactions of 1-3 with HSnBu₃ afford [Ru₃(μ-H)₂(μ₃,η ²-ampy)(SnBu₃)(PPh₃)_n(CO) _8-n] (n = 0 (4b), 1 (5b), 2 (6b)). In all cases, (a) the added hydride spans a metal-metal edge adjacent to that supported by the bridging amido group, (b) the SiEt₃ or SnBu₃ ligands occupy an equatorial site on the Ru atom bound to the two hydrides, being trans to the hydride which spans the same edge as the amido group, and (c) in the compounds containing PPh₃ ligands, these ligands occupy equatorial positions, cis to hydrides, on the Ru atoms bound to only one hydride. The reactions of 4a and 5a with PPh₃ produce the elimination of HSiEt₃, rendering the complexes 2 and 3, respectively; however, similar reactions of the tin-containing compounds 4b and 5b afford the substitution products 5b and 6b, respectively. The compounds have been characterized by infrared and ¹H, ¹³C, and ³¹P NMR spectroscopies and, in the case of 4a by X-ray diffraction. Crystal data for 4a: monoclinic, space group P2₁/n, a = 10.849 (8) A?, b = 20.809 (4) A?, c = 12.049 (8) A?, β = 98.21 (5)°, V = 2692 (2) A?³, Z = 4, μ(Mo Kα) = 17.17 cm^-1, R = 0.048, R_w = 0.053 for 2036 reflections and 287 variables.