Abstract: | Ligands containing unsaturated C2 and C4 units have been reacted with triruthenium dodecacarbonyl to produce new organometallic clusters with simple closo-RuxCy polyhedral frameworks which may be regarded as quasi-carboranes. The thermolysis of [Ru3(CO)12] with 1,4-diphenybutadiene yields the new clusters [Ru3(CO)8(μ3-CPh(CH)2CPh)] 2 and [Ru4(CO)9(μ4-CPhCCH2CH2Ph)] 3, while treatmentof a solution of [Ru3(CO)12] and diphenylacetylene with trimethylamine N–oxide (Me3NO) yields [Ru2(CO)6(μ-{C2Ph2}2CO)] 4 as the major product and the new cluster [Ru4(CO)11(μ4-C2Ph2)2] 5. The solid-state structures of 2, 3 and 5 have been established by single crystal X-ray diffraction analyses and are shown to possess closo-Ru3C4 pentagonal bipyramidal, closo-Ru4C2 octahedral and closo-Ru4C4 dodecahedral skeletons, respectively. The structure and bonding in all three clusters may be rationalised using the Wade–Mingos polyhedral skeletal electron pair approach. |