Alkyl borane compounds‐mediated polymerizations have expanded to Lewis pair polymerization, free radical polymerization, ionic ring‐opening polymerization, and polyhomologation. The bifunctional organoborane catalysts that contain the Lewis acid and ammonium or phosphonium salt in one molecule have demonstrated superior catalytic performance for ring‐opening polymerization of epoxides and ring‐opening copolymerization of epoxides and CO2 than their two‐component analogues, i.e., the blend of organoborane and ammonium or phosphonium salt. To explore the origin of the differences of the one‐component and two‐component organoborane catalysts, here we conducted a systematic investigation on the catalytic performances of these two kinds of organoborane catalysts via terpolymerization of epoxide, carbon dioxide and anhydride. The resultant terpolymers produced independently by bifunctional and binary organoborane catalyst exhibited distinct microstructures, where a series of gradient polyester‐polycarbonate terpolymers with varying polyester content were afforded using the bifunctional catalyst, while tapering diblock terpolymers were obtained using the binary system. The bifunctional catalyst enhances the competitiveness of CO2 insertion than anhydride, which leads to the premature incorporation of CO2 into the polymer chains and ultimately results in the formation of gradient terpolymers. DFT calculations revealed the role of electrostatic interaction and charge distribution caused by intramolecular synergistic effect for bifunctional organoborane catalyst.

中文翻译：

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通过环氧化物、CO2 和酸酐的三元聚合，深入了解双功能和二元有机硼烷催化剂之间的独特行为

烷基硼烷化合物介导的聚合已扩展到路易斯对聚合、自由基聚合、离子开环聚合和多同系化。在一个分子中含有路易斯酸和铵盐或鏻盐的双功能有机硼烷催化剂在环氧化物的开环聚合以及环氧化物和CO2的开环共聚方面表现出比其双组分类似物（即，有机硼烷和铵盐或鏻盐。为了探究单组分和双组分有机硼烷催化剂差异的根源，我们对这两种有机硼烷催化剂通过环氧化物、二氧化碳和酸酐的三聚反应的催化性能进行了系统研究。由双功能和二元有机硼烷催化剂独立生产的所得三元共聚物表现出独特的微观结构，其中使用双功能催化剂提供了一系列具有不同聚酯含量的梯度聚酯-聚碳酸酯三元共聚物，而使用二元体系获得了递变二嵌段三元共聚物。双功能催化剂比酸酐增强了CO2插入的竞争力，导致CO2过早掺入聚合物链中，最终导致梯度三元共聚物的形成。 DFT计算揭示了双功能有机硼烷催化剂分子内协同效应引起的静电相互作用和电荷分布的作用。