Iron clusters fluxionality

The majority of iron clusters are triangular Fe3 systems. Of these, the structure of the basic compound, Fe3(CO)i2, was only recently established with certainty 113, and its fluxional properties, although investigated in some detail 9, 111, 114,175,186, are still not fully understood. 

The metal clusters of the iron triad M3(CO)i2, 4 M = Fe, 5 M = Ru, and 6 M = Os, despite being some of the simplest carbonyl clusters known, are fascinating molecules, which still present interesting structural and dynamic problems. Because of their simplicity, they have been, and indeed remain, archetypal molecules for discussions on fluxional mechanisms. The two heavier congeners 5 and 6 have a clearer and less complicated history. In the solid state they are isostructural, and possess... 

Further work demonstrated that the addition of M(PBu 3) (M = Pd, Pt) groups to iron, ruthenium, and rhodium clusters is quite general. Thus, clusters of type 83-85 are readily synthesized all exhibit some degree of fluxionality. An alternative reagent, Pt(norbornene)3 (PPp3) n =, 2), has been used to introduce Pt(PPr 3) fragments to saturated triruthenium clusters. 

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