Ytterbium, cyclopentadienyl complexes oxidation

Watson (1980), Watson et al. (1981) and TiUey and Andersen (1981b) prepared bis(pentamethylcyclopentadienyl) ytterbium, lutetium, neodymium and samarium chlorides and iodides. Some physical data of these compounds together with those of the other complexes with substituted cyclopentadienyl ligands are given in table 8. The following synthetic methods have been used ytterbium metal is oxidized by CjMejI in the presence of Lil in ether to give, via CjMejYbl, the complexes shown in eq. (20). In the absence of Lil, only dimeric pentamethylcyclopentadiene was isolated. 

Samarium, europium, and ytterbium are the only rare-earth elements which exhibit an extensive chemistry in the oxidation state -l-II. Indeed, a few chelate complexes of ether-functionalized cyclopentadienyl ligands are known for samarium(II) and ytterbium-(II). 

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