HRU3(CO)10(COCH3) - CLUSTER WITH AN OXYGEN-CONTAINING MU-2-CARBYNE LIGAND - PREPARATION, STRUCTURE AND FLUXIONALITY

The cluster HRu3(CO)10(COCH3) has been prepared from Na[HRu3(CO)11] and [(CH3)3O]BF4 in acetonitrile. The complex crystallises in the monoclinic space group P21/c, with cell dimensions a 7.937(2), b 16.880(9), c 14.074(3) Å, β 104.16(3)° and Z 4. The structure was solved by a combination of Patterson and Fourier techniques and refined by full-matrix least-squares to final residues of R = 0.031 and Rw = 0.035 for the 2529 unique intensities. The three ruthenium atoms define an approximately equilateral triangle with one edge bridged by both a μ2-H and a μ2-COCH3 ligand. The fluxional behaviour of HRu3(CO)10-(COCH3) has been studied by variable temperature 13C NMR spectroscopy. The spectra are indicative of several dynamic processes occurring in solution over the range -100 to +90°C. The μ2-COCH3 species can be considered as a bridging three-electron donor and thus represents a μ2-carbyne ligand. © 1979.