Controlled Polymerization in Polar Solvents to Ultrahigh Molecular Weight Polyethylene.

Novel complexes based on 2,4,8-triarylnaphthylamine [[(2,4-{3,5-(CF3 )2 C6 H3 }2 -8-(3,5-R2 C6 H3 )-C10 H4 )-N═C(H)-{3-(9-anthryl)-2-O-C6 H3 }-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 ( Mw / Mn = 1.2 at Mn = 1.1 × 106 g mol-1 ).