Interactions Between Iron and Essential Metals

In l,3-dichalcogena-[3]ferrocenophanes of the type fc(E2M) (E = O, S, Se, Te), a transition metal complex fragment (M) is held firmly between the two chalcogen atoms (E) (Table 5-5). Although both the ferrocene iron and the transition metal are essential parts of the cyclic structure, the two metals generally remain isolated from each other. Only a few examples have been found where an intramolecular, transannular interaction between Fe and M can be taken into consideration, as in the palladium(ii) and platinum(ii) complexes fc[E2M(PPh3)] (E = O, M = Pd E = S, M = Pd and Pt) (Sect. 5.7.1). 

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