(Anilino)anthraquinone Nickel‐Catalyzed Random Copolymerization of Norbornene and Ethylene

Nickel complexes bearing an (anilino)anthraquinone ligand with different electron‐donating substituents were synthesized and shown to have unique properties for the random copolymerization of norbornene with ethylene. The nickel catalysts exhibited high activity (380–750 kg mol −1 h −1 ) and thermal stability in the production of cyclic olefin copolymers (COCs). The norbornene content of the obtained COCs could be controlled over a wide range (63.7–92.2 mol %) by changing the comonomer concentration in the feed. The glass transition temperature value increased linearly from 182 to 322 °C as a function of the norbornene content regardless of the nickel complex used.