Alkene polymerization by a cationic zirconium diamide complex formed by ligand cyclometallation

Abstract

Reaction of {(Me₃Si)₂N}₂Zr(CH₂Ph)₂ 1 with B(C₆F₅)₃ gives a cationic benzyl complex, which at –25 °C, expels toluene to afford {(Me₃Si)₂N}[graphic omitted]SiMe₃){ηⁿ-PhCH₂-B(C₆F₅)₃}2; strong anion coordination to zirconium in cyclometallation product 2 suppresses alkene polymerization, whereas the analogous cationic NMe₂Ph adduct 3, formed by protonolysis of 1, polymerizes both ethene and propene.