Treatment of [(η5-C5R5)Ru(L)2]BF4 (R = Me, (L)2 = dppe; R = H, (L)2 = (PPh3)2) with 0.45 equiv of HC⋮CCH(OH)C⋮CH led to the formation of the C5H2-bridged compounds [(η5-C5R5)(L)2RuCCCHCHCRu(L)2(η5-C5R5)](BF4)2. The C5H2-bridged compounds reacted with alumina to give the C5H-bridged compounds [(η5-C5R5)(L)2RuCCCHC⋮CRu(L)2(η5-C5R5)]BF4. The structure of the C5H-bridged complex [Cp(PPh3)2RuCCCHC⋮CRu(PPh3)2Cp]BPh4 has been confirmed by X-ray diffraction and shows the bridging C5H ligand to be symmetric with a delocalized π-system. Reaction of [(η5-C5R5)(L)2RuCCCHC⋮CRu(L)2(η5-C5R5)]BF4 with acetone in the presence of KOH or KOBu t produced (η5-C5R5)(L)2RuC⋮CCH(CH2COMe)C⋮CRu(L)2(η5-C5R5).

Reaction of Cp*RuH(COD) with HBF 4 ‚OEt 2 at -76 °C produced [Cp*Ru(H 2 )(COD)]BF 4 , which transformed to [Cp*Ru(η 6 -1,3,5-COT)]BF 4 on warming to room temperature. Reaction of Cp*RuH(NBD) with HBF 4 ‚OEt 2 produced a mixture of nortricyclene and the novel bimetallic complex [(Cp*Ru) 2 (µ-H)(µ-C 5 H 5 -CHd CH 2 )]BF 4 .