SYNTHESES AND STRUCTURES OF METHYL-RUTHENIUM, ACETYL-RUTHENIUM AND ALLYL-RUTHENIUM CARBIDOCARBONYL CLUSTERS

Reaction of the dianionic ruthenium carbidocarbonyl cluster [PPN]2[Ru6C(CO)16] (PPN = (PPh3)2N) (1) with methyl iodide at 120 ° C proceeds with retention of the octahedral metal framework and gives the methyl cluster [PPN][Ru6C(CO)16(CH3)] (3). Treatment of 3 with CO (50 atm) at room temperature gives the acetyl cluster [PPN][Ru6C(CO)16(COCH3)] (6). Reaction of 1 with allyl bromide at 85 ° C gives the allyl cluster [PPN][Ru6C(CO)15(C3H5)] (7) in which the allyl ligand coordiantes to one of the edges of the metal octahedron in μ,η3-manner. The structures of these clusters were unequivocally determined by X-ray diffraction. 3: monoclinic, space group P21/n, a 18.785(4), b 17.762(5), c 17.085(4) Å, β 94.42(2)°, Z = 4; R = 0.059, Rw = 0.050 for 5937 unique observed reflections. 6: monoclinic, P21/n (isomorphous with 3), a 18.965(5), b 17.646(7), c 17.366(5) Å, β 94.79(3)°, Z = 4; R = 0.069, Rw = 0.040 for 7156 unique observed reflections. 7: monoclinic, P21/a, a 19.343(3), b 19.099(3), c 15.802(3) Å, β 98.50(2)°, Z = 4; R = 0.054, Rw = 0.031 for 6304 unique observed reflections. © 1990.