Controlled Polymerization in Polar Solvents to Ultrahigh Molecular Weight Polyethylene

Novel complexes based on 2,4,8-triarylnaphthylamine [[(2,4-{3,5-(CF₃)₂C₆H₃}₂-8-(3,5-R₂C₆H₃)-C₁₀H₄)-N═C(H)-{3-(9-anthryl)-2-O-C₆H₃}-κ²-N,O]Ni(CH₃)(pyridine)] (4-Py, R = Me; 5-Py, R = CF₃) were synthesized from 8-arylnaphthylamines which can be generated via selective lithiation, borylation, and coupling in a one-pot procedure. Due to their living characteristics in ethylene polymerization and the particularly low propensity of 5-Py for β-H elimination as reflected by a high linearity even at elevated polymerization temperatures of 60 °C, ultrahigh molecular weight polyethylene (UHMWPE) is formed in polar organic solvents (THF, diethyl ether) as a reaction medium in a controlled polymerization ( M_w/ M_n = 1.2 at M_n = 1.1 × 10⁶ g mol^-1).