88031-63-4Relevant academic research and scientific papers
Site Specific Substitutions at Mixed Metal Clusters
Bantel, Harald,Bernhardt, Wolfgang,Powell, Anne K.,Vahrenkamp, Heinrich
, p. 1247 - 1256 (2007/10/02)
The phosphane substitution chemistry was investigated for (μ3-2-butyne)FeCo2(CO)9 and for the clusters (μ3-X)RuCo2(CO)9 with X = alkyne, vinylidene, sulfur, and phosphinidene.In the case of the FeCo2 cluster Co-substitution was observed exclusively.For the RuCo2 clusters Co- as well as Ru-substituted products were isolated, of which in all cases the Co-substituted one is kinetically favoured and the Ru-substituted one thermodynamically favoured.The thermally induced Co-Ru migration of the phosphane ligands could be realized in several cases; the migratory aptitude decreases in the sequence PMe3, PMe2Ph, PMePh2, PPh3.Competition experiments with (μ3-2-butyne)FeCo2(CO)9, (μ3-2-butyne)RuCo2(CO)9 and PPh3 demonstrated a higher substitutional lability of the FeCo2 cluster and a phosphane transfer from the FeCo2 to the RuCo2 cluster.Some of the phosphane reactions led also to distribution (at the same or at different metal atoms).Crystal structure analyses of (μ3-HCCMe)RuCo2(CO)8(PPh3)(P-Co) (9d), (μ3-C=CHMe)RuCo2(CO)8(PMe2-Ph)(P-Ru) (19b), (μ3-S)RuCo2(CO)8(PPh3)(P-Co) (23d), and (μ3-S)RuCo2(CO)8(PMe2Ph)(P-Ru) (24b) confirmed the constitutional assignments deduced from the spectra.Altogether the metals considered here show a tendency for substitution in the order Fe Co Ru.
