Coupling reaction between the uncoordinated acetylenic bond of [Ru3(CO)10{μ3-FcC2Ctriple bond; length of mdashCFc}] and FcCtriple bond; length of mdashCCtriple bond; length of mdashCFc to form [Ru2(CO)6{C4Fc2(Ctriple bond; length of mdashCFc)2}2], [Ru2(CO

Low temperature photolysis of a hexane solution of [Ru3(CO)12] and FcCtriple bond; length of mdashCCtriple bond; length of mdashCFc provides a convenient route to the diyne-bridged cluster [Ru3(CO)10{μ3-FcC2Ctriple bond; length of mdashCFc}] (1). When a toluene solution containing 1 and diferrocenyldiacetylene was heated at 80 °C three compounds formed: the ruthenacyclopentadiene complex [Ru2(CO)6{C4Fc2(Ctriple bond; length of mdashCFc)2}2] (2), and two isomers of the diruthenacycloheptadienone complex, [Ru2(CO)6[μ-η1:η1:η2:η2-{FcCtriple bond; length of mdashCCC(Fc)–C(O)–C(Fc)CCtriple bond; length of mdashCFc}] (3), [Ru2(CO)6[μ-η1:η1:η2:η2-{FcCtriple bond; length of mdashCCC(Fc)–C(O)–C(–Ctriple bond; length of mdashCFc)C(Fc)}] (4). Compounds 2–4 have been characterized spectroscopically and their structures established crystallographically. Consistent with structural reports on metallacyclic compounds bearing bulky substituents, in 2 and 3, the bulkier of the two types of substituents, the Ctriple bond; length of mdashCFc groups are located on the carbon atoms adjacent to the metal atoms, whereas in compound 4, only one of the two Ctriple bond; length of mdashCFc groups is on the α-carbon atom of the ruthenacyclopentadienone ring.