Reactions of cationic palladium alpha-diimine complexes with nitrogen-containing olefins:Branched polyethylene with carbazole functionalities

The reactivity of three nitrogen-containing olefins with a cationic (alpha-diimine)Pd-Me species was studied to evaluate possibilities for their catalytic copolymerization with ethylene. Allyl dimethyl amine gives 1,2-insertion into the Pd-Me bond, but the resulting five-membered chelate is inert toward ethylene. Olefins bearing carbazole substituents insert to form three-membered chelate complexes after a chain-walking process. These chelates are reactive toward ethylene, and N-pentenylcarbazole was successfully copolymerized with ethylene to yield branched polyethylene copolymers bearing carbazole functionalities. The fluorescence of these copolymers is dependent on the amount of incorporated comonomer.