Zirconocenes ring-functionalized

Reduction of 2-methoxyethyl- and 2-methylthioethyl-functionalized zirconocene dichlorides with Mg/Hg in THF leads to the products of the O-Me and S-Me bond cleavage.647 For example, the reduction of (G5Me4GH2CH2EMe)(G5Me5)ZrCl2 (E = O, S) with Mg/Hg in THF gives the chelating (ring-metallated) complex... 

As an alternative approach, polycarbosilanes 2.31 bearing pendant zirconocene moieties have also been prepared by ring-opening polymerization of the spirocyc-lic monomer 2.30 (Eq. 2.13) [62], In this case, the materials were structurally characterized, but the soluble fraction was of low molecular weight (M < ca. 3000) and the high molecular weight fraction was insoluble in organic solvents. In the presence of activators, both fractions functioned as ethene polymerization catalysts with moderate activity [62]. 

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