Butterfly Cluster Complexes of the Group VIII Transition Metals

Reaction of the Heteronuclear Cluster [Cp*IrRu3(μ‐H)2(CO)10] with Alkynes: Stereoselective Binding

“…This indicated clearly that the equilibrium lies towards the ʈRu-Ru isomer 2g 3 , i.e., that it was the thermodynamically most stable isomer. This is in agreement with the earlier observations on the [FeRu 3 (μ-H) 2 (CO) 13 ] and [Cp/Cp*RhRu 3 (μ-H) 4 -(CO) 9 ] systems. [9,10] As a natural extension from the above reactions with alkynes, we attempted the reaction of 1 with 1-hexene to see if cluster-olefin complexes may be prepared, but none could be isolated.…”

“…Heterometallic clusters like the previously reported [CpRhRu 3 (μ-H) 4 (CO) 9 ] are attractive as they allow for the study of site selectivity in the binding of alkynes, particularly unsymmetrical alkynes; the Cp serves as a ligand which allows for stereoelectronic influence on the cluster. However, this cluster was known to fragment readily under the reaction conditions, [10] and we thus sought to examine the reactivities of some heavier relatives, viz., [Cp*IrM 3 (μ-H) 2 (CO) 10 ] [M = Ru (1) or Os], which we have recently synthesised, [24] in the hope that the third-row elements would lend stability to the cluster core.…”

“…[3] The reaction of tetrahedral clusters with alkynes often results in cluster opening to give "butterfly" structures, [4] where the M 3 MЈ skeleton takes the form of a butterfly and the alkyne C 2 unit binds to the metal framework in a μ 4 -η 2 fashion to form a quasi-octahedral M 3 MЈC 2 skeleton. [5] The total electron count for these clusters are best considered using the Wade's system, i.e., as octahedral M 3 MЈC 2 clusters, with each CR unit donating three electrons to the skeletal bonding.…”

Tetranuclear group 7/8 mixed-metal and open trinuclear group 7 metal carbonyl clusters bearing bridging 2-mercapto-1-methylimidazole ligands

“…5- 18 In addition, heterobimetallic complexes may combine the catalytic features of each metal to provide new and unique reactivity that is inaccessible by the homobimetallic systems. 22, 23 They have been studied as intermediates in homogeneous catalytic processes, 23-25 and also considered as a model for chemisorption of small molecules. 22, 23 They have been studied as intermediates in homogeneous catalytic processes, 23-25 and also considered as a model for chemisorption of small molecules.…”

Reactions of Co2(CO)8 and of Co2(CO)6L (L=3-pentyn-1-ol, 1,4-butyn-diol or 2-methyl-3-butyn-2-ol) with 2(diphenylphosphino)ethyl-trietoxysilane and tris(hydroxymethyl)phosphine for applications to new sol–gel materials

“…In spite of many attempts (by changing solvent and conditions) crystals of (4) suitable for X-ray analysis could not be obtained. The IR spectra indicate the presence of two bridging carbonyls and the NMR data and the CI and ESI mass spectra exclude the possibility that (4) is a Co 4 (CO) 8 (l-CO) 2 (L) butterfly [18] or a Co 3 (CO) 7 (l-CO) 2 (l 3 -L) methylidyne complex [19]. The proposed structure is therefore Co 2 (l-CO) 2 (CO) 5 (dpts) and is shown in the Fig.…”