Secondary Alkene Insertion and Precision Chain-Walking: A New Route to Semicrystalline “Polyethylene” from α‑Olefins by Combining Two Rare Catalytic Events

Abstract

While traditional polymerization of linear α-olefins (LAOs) typically provides amorphous, low <i>T</i>_g polymers, chain-straightening polymerization represents a route to semicrystalline materials. A series of α-diimine nickel catalysts were tested for the polymerization of various LAOs. Although known systems yielded amorphous or low-melting polymers, the “sandwich” α-diimines <b>3</b>–<b>6</b> yielded semicrystalline “polyethylene” comprised primarily of unbranched repeat units via a combination of uncommon regioselective 2,1-insertion and precision chain-walking events