Reaction of Ru3(CO)10 with diarylacetylenes; synthesis and subsequent reaction of a -hexacarbonyl diruthenium complex with propyne. Crystal and molecular structures of Ru2(CO)6, and of Ru2<μ-O=CNMe

Article abstract of DOI:10.1016/0022-328X(90)87248-C

The complex Ru3<μ-O=CNMe2,μ-H>(CO)10 (1) is observed to react with diphenylacetylene (2a), di(p-tolyl)acetylene (2b), or di(p-anisyl)acetylene (2c), at 23 deg C in hexane solution over a period of 12 h to give Ru2<μ-O=CNMe2,μ-?,?-C(Ar)=CH(Ar)>(CO)6, Ar = Ph (3a), p-CH3C6H4 (3b), or p-CH3OC6H4 (3c).Principal by-products are Ru3(CO)12 and the acetylene oligomerization complexes , Ar = C6H5 (4a), Ar = p-tolyl, CH3C6H4 (4b), Ar = p-anisyl, CH3OC6H4 (4c).Variable temperature ¹³C NMR of 3a, 3b, and 3c indicates the presence of tworapidly interconverting isomers in solution, one with geminal and the other with vicinal bridging groups.Complex 3b is observed to react with propyne at 23 deg C in hexane over a period of 4 h giving as principal product Ru2<μ-O=CNMe2,μ-?,?-C(CH3)=C(H)C(p-tolyl)CH(p-tolyl)>(CO)6, 5.The crystal and molecular structures of 3b and 5 have been determined using graphite-monochromatized Mo-K_α radiation on a Huber four circle diffractometer under control of a VAX 11/750 computer.Complex 3b crystallizes in the monoclinic space group P2₁/a; cell dimensions a = 20.1744(23), b = 7.3166(8), c = 18.9413(22) Angstroem, and β = 93.2730(31) deg and Z = 4, V = 2786.12 Angstroem³; ρ(calc.) = 1.55 g cm^-3.A total of 3923 unique reflections with I > 3?(I) were used in the refinement; final discrepancy indices, R = 0.057 and R_w 0.071.The crystal consists of discrete molecules of the complex in which the metal-metal separation Ru(1) - Ru(2) = 2.739(1) Angstroem.The two bridgind groups, namely <μ-?, ?-C(50)(Ar)=C(40)H(Ar)> and , are seen be attached to the two metal centers in a vicinal arrangement with a near octahedral arrangement of ?-bonded atoms around each metal.Bond distance parameters for the bridging groups are (Angstroem): Ru(2) - O(30) = 2.117(5); O(30) - C(30) = 1.283(8); Ru(1) - C(30) = 2.106(7), Ru(1) - C(50) = 2.324(7); Ru(1) - C(40) = 1.410(9); Ru(2) - C(50) = 2.081(7); C(40) - c(50) = 1.410(9). Complex 5 crystallizes in the monoclinic space group P2₁/c with cell dimensions: a = 10.421(4), b = 33.157(10), c = 8.896(3) Angstroem, β = 90.34(3) deg and Z = 4, V = 3078 Angstroem³, ρ(calc.) = 1.49 g cm^-3.The structure was solved by the heavy atom method.A total of 3159 unique reflections with I > 3?(I) were used in the refinement; final discrepancy indices, R_F = 0.085 and R_wF = 0.110.Complex 5 consists of two tricarbonyl ruthenium fragments joined by a strong Ru-Ru bond, 2.726(2) Angstroem, accompanied by a bridging carboxamido group and a bridging ?,?-group (C(CH3)=C(H)R (R = C(p-tolyl)=C(H)p-tolyl) in a sigma-geminal arrangement.This type of complex is preceived as a common intermediate to the oligomerization products 4a, 4b, 4c observed in the present and previous studies and the complex...