Coupling reaction between the uncoordinated acetylenic bond of [Ru3(CO)10{μ3−FcC2≡ CFc}] and FcC≡CC≡ CFc to form [Ru2(CO)6{C4Fc2(C≡ CFc)2}2], [Ru2(CO)6[μ-η1:η1:η2:η2-{FcC≡CCC(Fc)–C(O)–C(Fc)CC≡CFc}] and [Ru2(CO)6[μ-η1:η1: η2:η2-{FcC≡CCC(Fc)–C(O)–C(–C≡ CFc)C(Fc)}]

Abstract

Low temperature photolysis of a hexane solution of [Ru3(CO)12] and FcC≡CC≡CFc provides a convenient route to the diyne-bridged cluster [Ru3(CO)10{μ3-FcC2C≡CFc}] (1). When a toluene solution containing 1 and diferrocenyldiacetylene was heated at 80 °C three compounds formed: the ruthenacyclopentadiene complex [Ru2(CO)6{C4Fc2(C≡ CFc)2}2] (2), and two isomers of the diruthenacycloheptadienone complex, [Ru2(CO)6[μ-η1:η1:η2:η2-{FcC≡CCC(Fc)–C(O)–C(Fc)CC≡CFc}] (3), [Ru2(CO)6[μ-η1:η1:η2:η2-{FcC≡CCC(Fc)–C(O)–C(–C≡CFc)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 C≡CFc groups are located on the carbon atoms adjacent to the metal atoms, whereas in compound 4, only one of the two C≡CFc groups is on the α-carbon atom of the ruthenacyclopentadienone ring.