The synthesis and structural analyses of ruthenium carbonyl cluster complexes containing the bis-(trimethylsilyl)hexatriyne ligand

Abstract

Two ruthenium carbonyl cluster complexes: Ru 3(CO) 10[μ 3-η 2-C 2(CCSiMe 3) 2], 2 (6% yield) and Ru 4(CO) 12[μ 4-η 2-C 2(CCSiMe 3) 2], 3 (36% yield) were obtained from the reaction of the 1,6-bis-(trimethylsilyl)-1,3,5-hexatriyne, 1 with Ru(CO) 5 at 25°C. Both compounds were characterized by a single crystal X-ray diffraction analysis. In both cases the Ru cluster is located on the central alkyne unit of the triyne 1. Compound 2 contains a Ru 3 triangle with the alkyne coordinated in the common μ 3-∣ ∣ mode. In compound 3 the alkyne is coordinated in a μ 4-mode. The lengths of the coordinated alkyne C–C bonds are considerably longer than the uncoordinated alkyne C–C bond lengths. Compound 2 was also obtained in a better yield (60%) from the reaction of 1 with Ru 3(CO) 10(NCMe) 2. Compound 2 reacts with Ru(CO) 5 to yield compound 3, indicating that it is probably a precursor to 3 in the original reaction.