Formation of a Diynedienyl Ligand by Coupling of Hexa-2,4-diyne and Hex-2-yn-4-en-4-yl Ligands onto a Triruthenium Cluster Core

The reaction of the cluster complex [Ru3(μ-Η)(μ3-η2-ampy)(CO)9] (Hampy = 2-amino-6-methylpyridine) with an excess of hexa-2,4-diyne gives the trinuclear derivative [Ru3(μ3-η2-ampy){μ-η5-MeC⋮CC(CHMe)CMeCC⋮CMe}(μ-CO)2(CO)5] as the final product. This compound contains an unprecedented diynedienyl ligand that arises from the coupling of hexa-2,4-diyne with the hex-2-yn-4-en-4-yl ligand of the intermediate [Ru3(μ3-η2-ampy)(μ-η3-MeCHCC⋮CMe)(μ-CO)2(CO)6], which is the first compound observed in the reaction of 1 with hexa-2,4-diyne.