MU3-OXO-TRIRUTHENIUM ACETATE CLUSTER COMPLEXES AS CATALYSTS FOR OLEFIN HYDROGENATION

µ3-Oxo-triruthenium (III) acetate, [Ru3O(OCOCH3)6(H2O)3] [OCOCH3], when treated with H2 in dimethylformamide was found to be effective in providing novel triruthenium acetate cluster complexes which were active for the quantitative hydrogenation of a variety of olefinic and acetylenic compounds in dimethylformamide at 80 °C. Initially, the hydrogenation of the unsaturated substrate was catalyzed by the monohydridic triruthenium cluster complex [HRu3O(OCOCH3)5-(DMF)3][OCOCH3] which was also found to catalyze the isomerization of terminal olefins in the absence of hydrogen. In the case of terminal and internal straight chain olefins, this monohydride triruthenium cluster was found to undergo a facile intramolecular reduction to form [Ru3O(OCOCH3)4(DMF)n] [OCOCH3]. This cluster complex served as the catalyst for the major part of the olefin hydrogenation. The results of a detailed kinetic study are reported, and a plausible mechanism is presented for the hydrogenation of dec-1-ene in dimethylformamide. A very important and significant finding of this study is that only one ruthenium center of the cluster complex ion, [Ru3O(OCOCH3)4(DMF)n]+, is active in coordinating both the hydrogen and the olefin molecule and in transferring the hydrogen to the olefin. Although the other two ruthenium centers of the cluster also possess coordinative unsaturation, they function merely as metal entities present in a polydentate ligand. These metal entities do not appear to become involved in coordination to the reacting molecules. © 1979, American Chemical Society. All rights reserved.