Syndiospecific Polymerization Catalysts for Styrene Based on Rare Earth Metal Half‐Sandwich Complexes

Abstract

Abstract In the presence of an trialkyl aluminum cocatalyst the activation of scandium, yttrium and lutetium mono(cyclopentadienyl) complexes with various substituted cyclopentadienyl ligands by [Ph 3 C][B(C 6 F 5 ) 4 ] results in highly efficient catalysts for the syndiospecific polymerization of styrene. As active species half‐sandwich alkyl cations is assumed that is isostructural with the mono(cyclopentadienyl) titanium alkyl cation originally proposed by Zambelli.