Group 4 Metal Complexes That Contain a Thioether‐Functionalized Phenolato Ligand: Synthesis, Structure, and 1‐Hexene Polymerization

Reaction of group 4 metal tetrabenzyl complexes [M(CH2Ph)4] (M = Ti, Zr, Hf) with 1 or 2 equiv. of a thioether-functionalized phenol 2,4-tBu2-6-(PhSCH2)C6H2OH afforded dibenzyl complexes [M(L)2(CH2Ph)2] (M = Ti, 1; M = Zr, 2; M = Hf, 3) and the tribenzyl zirconium complex [Zr(L)(CH2Ph)3] (4). Benzyl abstraction with a Lewis acid gave the zirconium monobenzyl cation [Zr(L)2CH2Ph]+[PhCH2B(C6F5)3]– (5) and the dibenzyl cation [Zr(L)(CH2Ph)2]+[PhCH2B(C6F5)3]– (6). The monobenzyl cation 5 oligomerized 1-hexene to low molecular-weight atactic oligo(1-hexene) (Mn = 560–820), while the dibenzyl cation 6 polymerized 1-hexene isospecifically ([mmmm] > 90 %). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)