CLUSTER-MEDIATED RING CONTRACTION - SYNTHESIS AND CHARACTERIZATION OF(3)-H)(MU(4)-ETA(2)-CO)(2)(CO)(13)(ETA(5)-C5H4ME)] AND )-H)(MU(4)-ETA(2)-CO)(2)(CO)(13)(ETA(5)-C5H3C3H6)]

The thermolysis of [Ru-3(CO)(12)] with either cyclohexene or cycloocta -1,3-diene resulted ina number of cluster derivatives, including one f rom each reaction in which the ligand has undergone a ring contraction . Reaction with cyclohexene afforded the methylcyclopentadienyl cluste r (3)-H)(mu(4)-eta(2)-CO)(2)(CO)(13)(eta(5)-C5H4Me)] 1, whilst cyclooc ta-1,3-diene yielded the trihydropentalenyl cluster mu(3)-H)(mu(4)-eta (2)-CO)(2)(CO)(13)(eta(5)-C8H9)] 2. The molecular structures of 1 and 2 have been established in the solid state by single-crystal X-ray dif fraction.