CLUSTER COMPLEXES CONTAINING YNAMINE LIGANDS .2. REACTIONS OF MEC=CNME2 WITH FE3(CO)10(MU-3-S), RU3(CO)10(MU-3-S), OS3(CO)10(MU-3-S) AND STRUCTURAL CHARACTERIZATIONS OF RU2(CO)6[MU-SC(NME2)CME], RU2(CO)6[MU-SCMEC(NME2)], AND OS3(CO)9[MU-3-MEC2NME2](MU-3-S)

The reactions of the compounds M3(CO)10(μ3-S) (la, M = Fe; lb, M = Ru) with MeC2NMe2 yielded the products M2(CO)6[μ -SC(NMe2)CMe] (2a, M = Fe, 3%; 2b, M = Ru, 36%) and M3(CO)9[μ3-MeC2NMe2](μ3-S) (3a, M = Fe, 30%; 3b, M = Ru, 147o). The reaction of OS3(CO)10(μ3-S) (lc) with MeC2NMe2 yielded only the trinuclear product Os3(CO)9[μ3-MeC2NMe2](μ3-S) (3c, 87%). Compounds 2b and 3c were characterized by single-crystal X-ray diffraction analyses. Compound 2b consists of a metal-metal-bonded Ru2(CO)6 grouping bridged by a SC(NMe2)CMe ligand. The sulfur and C-methyl carbon atom are strongly bonded to both metal atoms. The NMe2-substituted carbon atom is weakly bonded to one metal atom and not bonded to the other. Compound 3c consists of an open triosmium cluster with a triply bridging sulfido ligand and a triply bridging MeC2NMe2 ligand. The C-methyl carbon atom is bonded to two metal atoms. The NMe2-substituted carbon atom is coordinated only to the one remaining metal atom. Structurally, this grouping resembles an NMe2-substituted carbene ligand. This is also supported by the 13C NMR spectrum, which shows a very low field resonance, +251.92 ppm for 3a and +243.50 ppm for 3c. It is proposed that the ynamine ligands in the compounds 3a-c should be formulated as (α, α-dimetallioethyl)(dimethylamino)carbene ligands. Compound 2b isomerizes when heated to form the compound Ru2(CO)6[μ-SC(Me)CNMe2] (2b') in 38% yield. Compound 2b' was characterized structurally. The structure is similar to that of 2b except that the methyl-substituted carbon atom is bonded to the sulfur atom and the NMe2-substituted carbon atom is not a bridging atom but is terminally coordinated to one of the metal atoms. The iron homologue of 2b', Fe2(CO)6[μ -SC(Me)CNMe2] (2a'), was obtained (55% yield) by pyrolysis of 3a at 100 °C. Crystal data: for 2b, space group PI, o = 9.189 (1) Å, b = 11.705 (3) Å, c = 8.213 (1) Å, α = 106.18 (1)°, β = 110.06 (1)°, γ = 79.60 (2)°, V = 793.3 (3) Å3, Z = 2, R = 0.020, and Rw = 0.023 for 2373 reflections; for 2b', space group P21/n, a = 10.531 (2) Å, b = 10.799 (2) Å, c = 14.336 (3) Å, β = 98.07 (2)°, V = 1614 (1) Å3, Z = 4, R = 0.025, andRw = 0.026 for 1615 reflections; for 3c, space group Pl, a = 9.397 (4) Å, b = 13.406 (7) Å, c = 8.914 (3) Å, α = 92.84 (4)°, β = 115.20 (3)°, γ = 97.54 (4)°, V = 1000.3 (8) Å3, Z = 2, R = 0.030, and Rw = 0.035 for 2814 reflections. © 1990, American Chemical Society. All rights reserved.