Synthesis and molecular structure of mixed alkyne-cyclopentadienyl clusters via the ionic coupling of [Os3(CO)9(R2C2)]2− with [Ru(η5-C5H5)(MeCN)3]+ and the reaction [Os3RuH(η5-C5H5)(CO)10(MeCN)] with alkynes (R2C2) (R = Me, Ph)

The ionic coupling reaction of the dianion [Os3(CO)9(R2C2)]2− (R = Me, Ph) with two equivalents of the monocation [Ru(η5-C5H5)(CH3CN)3]+ affords the neutral clusters [Os3Ru2(CO)9(R2C2)(η5-C5H5)2] [R = Me, 1 and R = Ph, 2] in ca. 80% yield. An X-ray crystallographic study of 1 confirms that these clusters exhibit a capped pseudo-octahedral Os3Ru2C2 core, with the alkyne bonded parallel to the hinge bond of the capped butterfly metal geometry in a μ4–η2 manner, the Ru atoms adopting the wing-tip and capping positions. Reaction of the activated cluster [Os3RuH(η5-C5H5)(CO)10(MeCN)] (3) with RCCR (R = Me, Ph) affords the related clusters [Os3RuH(CO)9(η5-C5H5)(R2C2)] (R = Me, 4 and R = Ph, 5) in ca. 35% yield. The reaction with PhCCPh also produces [Os3Ru(CO)8(η5-C5H5)(PhCCPh)(PhCC(H)Ph)] (6) in ca. 15% yield. An X-ray crystallographic study shows that this cluster has a pseudo-octahedral Os3RuC2 core, with the Ru(η5-C5H5) unit adopting the wing-tip position, the alkyne bonded in a μ4–η2 arrangement and the ethenyl ligand bridging an Os–Os edge in a μ2–η1:η2 configuration.

The coupling reaction of the dianion [Os3(CO)9(R2C2)]2− (R = Me, Ph) with two equivalents of the monocation [Ru(η5-C5H5)(CH3CN)3]+ affords the neutral clusters [Os3Ru2(CO)9(R2C2)(η5-C5H5)2]. These clusters exhibit a capped pseudo-octahedral Os3Ru2C2 core, with the alkyne bonded parallel to the hinge bond of the capped butterfly metal geometry in a μ4-η2 manner. Similarly, reaction of the activated cluster [Os3RuH(η5-C5H5)(CO)10(MeCN)] with RCCR (R = Me, Ph) affords the related clusters [Os3RuH(CO)9(η5-C5H5)(R2C2)].Figure optionsDownload as PowerPoint slide