New electron-deficient alkene and alkyne derivatives of Ru5(μ5-C)(CO)15: The syntheses and crystal structure analyses of Ru5(μ5-C)(CO)13 [C2H2(CO2Me)2] and Ru5(μ5-C)(CO)15 [C2(CO2Me)2]

Abstract

Treatment of carbido cluster Rus(/zs-C)(CO)~5 with Me3NO in acetonitrile solution followed by addition of dimethyl maleate or dimethyl acetylene dicarboxylate affords new clusters Rus(/zs-C)(CO)~3[C2H2(CO2Me)2] (1) and Rus(/zs-C)(CO)Is[C2(CO2Me)2] (2), respectively. Single crystal X-ray structural studies reveal that both complexes contain a wingtip-bridged butterfly pentametallic skeleton. In complex 1 the maleate fragment is coordinated to one wingtip Ru atom through its carbon-carbon double bond and to the adjacent Ru atom by the formation of two O ~ Ru dative bonding interactions, while the acetylene dicarboxylate fragment in 2 is best considered as a cis-dimetaUated alkene, linking one hinge Ru atom and the nearby Ru atom at the bridged position.

Stepwise Formation of Heterometallic Cluster Compounds (C5Me5)WRu5(μ6-C)(μ-CCH2Ph)(μ-H)2(CO)13and (C5Me5)WRu5(μ4-C)(μ3-CCH2Ph)(μ-H)4(CO)12from Ru5(μ5-C)(CO)15. Reactivity Studies of Carbido Clusters Bearing Acetylide Ligands

“…Synthesis and Characterization of 1 and 2. The carbido cluster Ru 5 (μ 5 -C)(CO) 15 reacts with 2 equiv of the oxidative decarbonylation reagent Me 3 NO in acetonitrile solution at room temperature to afford an unstable light red complex which is tentatively assigned to have the empirical formula Ru 5 (μ 5 -C)(CO) 13 (NCMe) 2 …”

“…It is possible that the reaction proceeds through the coordination of the acetylide C−C triple bond to the Ru 5 framework, which links the LW(CO) 3 pendant in the vicinity of the Ru 5 framework, and then promotes the formation of two W−Ru bonds via CO elimination. The isolation of the alkyne complex Ru 5 (μ 5 -C)[C 2 (CO 2 Me) 2 ](CO) 15 from addition of dimethyl acetylenedicarboxylate to the parent carbido cluster Ru 5 (μ 5 -C)(CO) 15 serves as evidence in favor of this postulate 1 …”