Synthesis and structural characterization of (mu-H)(2)Ru-3(CO)(9)(mu(3)-eta(2)-C8H12) and (mu-H)Ru-3(CO)(9)(mu(3)-eta(3)-C12H19)

The reaction between Ru-3(CO)(12) and a cyclic olefin (cis-cyclooctene or trans-cyclododecene) at 100 degrees C for several hours gives the title compounds (mu-H)(2)Ru-3(CO)(9)(mu(3)-eta(2)-C8H12) (1), and (mu-H)Ru-3(CO)(9)(mu(3)-eta(3)-C12H19) (2), both of which have been characterized by X-ray diffraction studies, IR and NMR spectral measurements and elemental analysis. The prolonged reaction between Ru-3(CO)(12) and cis-cyclooctene gives compound HRu3(CO)(9)(C8H11) (3). Compound 3 has been characterized with IR and NMR spectral analyses. In 1 the cyclooctene ring is linked via a mu(3)-eta(2)-alkyne type of bonding to the face of the Ru, cluster. It is formally sigma-bonded to two of the three Ru atoms and pi-bonded to the third Ru. The two hydrides in 1 are bridging Ru-Ru bonds. In 2 the cyclododecene ring is bonded to the Ru, face via the mu(3)-eta(3)-CCHC linkage. There are two formal sigma-bonds from the allyl part to the hydride-bridged Ru atoms and the eta(3)-allyl linkage to the third Ru atom.