Synthesis and Chemical Transformation of Nitrogen-Rich Polyolefins through Copolymerization of Ethylene with Polar Cyclic Olefins

作者：Kangkang Li, Lei Cui, Yixin Zhang, Zhongbao Jian · 发表于：Macromolecules · 年份：2025 · DOI：10.1021/acs.macromol.5c01720 · 被引用次数：5 · 研究领域：Organometallic Complex Synthesis and Catalysis、Synthetic Organic Chemistry Methods、Carbon dioxide utilization in catalysis

Direct coordination–insertion copolymerization of ethylene with polar monomers provides an atom- and energy-efficient route to functionalized polyolefins. However, the incorporation of nitrogen-containing comonomers into polyolefins remains problematic due to nitrogen-induced catalyst poisoning. Herein, two highly strained bicyclic nitrogen-containing comonomers (aminooxy-embedded norbornene: NB NO, aza-embedded norbornene: NB NN ) are introduced, which effectively diminish the catalyst poisoning propensity. The copolymerization of ethylene with NB NO results in the formation of poly(E- NB NO ) with high comonomer incorporation of 38.3 mol %. Likewise, the reaction with NB NN produces poly(E- NB NN ), which possesses both high molecular weight of 108.1 × 10 3 g mol –1 and high comonomer incorporation of 28.3 mol %. By adjusting the concentration of NB NN, the semicrystalline poly(E- NB NN ) ( T m = 126–127 °C) is transformed into the amorphous, transparent, optical poly(E- NB NN ) ( T g = 60–132 °C; transmittance = 95.2–96.6% at 400 nm). Notably, poly(E- NB NO ) undergoes N–O reductive cleavage, giving bifunctional poly(E-NH–OH) that features both −OH and −NH moieties. Poly(E- NB NN ) is transformed into an azo-containing polyolefin [poly(E-N═N)]. Precise modulation of the N 2 -extrusion conditions in poly(E-N═N) enables the formation of diverse all-hydrocarbon cyclo-containing polyolefin architectures, which are difficult to access by other methods. This work circumvents con...