Semi‐Crystalline Polar Polyethylene: Ester‐Functionalized Linear Polyolefins Enabled by a Functional‐Group‐Tolerant,Cationic Nickel Catalyst

A dibenzobarrelene‐bridged, α‐diimine Ni^II catalyst (rac‐ 3 ) was synthesized and shown to have exceptional behavior for the polymerization of ethylene. The catalyst afforded high molecular weight polyethylenes with narrow dispersities and degrees of branching much lower than those made by related α‐diimine nickel catalysts. Catalyst rac‐ 3 demonstrated living behavior at room temperature, produced linear polyethylene (T_m=135 °C) at ?20 °C, and, most importantly, was able to copolymerize ethylene with the biorenewable polar monomer methyl 10‐undecenoate to yield highly linear ester‐functionalized polyethylene.