Zirconium Complexes of a Rigid, Dianionic Pincer Ligand: Alkyl Cations, Arene Coordination, and Ethylene Polymerization

Abstract

Reaction of 4,5-bis(2,4,6-triisopropylanilino)-2,7-di-tert-butyl-9,9-dimethylxanthene (H2XN2) with [Zr(NMe2)4], followed by crystallization from O(SiMe3)2, yielded [(XN2)Zr(NMe2)2]·{O(SiMe3)2}0.5 (1·{O(SiMe3)2}0.5). The zirconium dimethyl complex [(XN2)ZrMe2] (2) was subsequently accessed (a) by treatment of 1·(O(SiMe3)2)0.5 with excess AlMe3 or (b) via reaction of 1·(O(SiMe3)2)0.5 with excess Me3SiCl, affording [(XN2)ZrCl2] (3) …