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

Two ruthenium carbonyl cluster complexes: Ru-3(CO)(10)[mu(3)-eta(2)-C-2(C=CSiMe3)(2)], 2 (6% yield) and Ru-4(CO)(12)[mu(4)-eta(2)-C-2(C=CSiMe3)(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 degrees 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 mu(3)-parallel to mode. In compound 3 the alkyne is coordinated in a mu(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. (C) 1999 Elsevier Science S.A. All rights reserved.