The first examples of bifunctional hyperbranched polymers (HBP) with high density ionic liquid (IL) moieties in the main chain and controllable amount of pyrene groups at the chain ends (Py-HBPIL) have been synthesized via a facile three-step procedure, which were then immobilized onto reduced graphene oxide (rGO) via π–π stacking interactions. Py-HBPIL(Br) bearing pyrene groups at 10% of the chain ends allowed the highest immobilization loading of 73% in weight. The resultant Py-HBPIL(Br)@rGO hybrid material displayed much better catalytic activity than ever reported for immobilized IL catalysts for coupling reaction between CO₂ and propylene oxide (PO), and it could be reused up to 6 times by simple filtration process without significant decline in activity. Furthermore, the combination of bifunctional HBP and π–π stacking immobilization may provide a general and versatile platform to design highly active, selective and recyclable catalysts for various chemical transformations.

中文翻译：

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graph末端超支化三唑基高分子离子液体在石墨烯上的非共价固定化，以实现高活性和可循环利用的CO ₂ /环氧化物环加成催化

通过简便的三步法合成了在主链上具有高密度离子液体（IL）部分且链端可控制的of基数量（Py-HBPIL）的双功能超支化聚合物（HBP）的第一个实例。然后通过π-π堆积相互作用将其固定在还原的氧化石墨烯（rGO）上。在链端的10％处带有pyr基的Py-HBPIL（Br）可以实现73％重量的最高固定负载。所得的Py-HBPIL（Br）@rGO杂化材料显示出比以往报道的用于固定化IL催化剂的CO ₂之间偶联反应更好的催化活性。和环氧丙烷（PO），通过简单的过滤过程最多可重复使用6次，而活性没有明显下降。此外，双功能HBP和π–π堆叠固定化的结合可以为设计用于各种化学转化的高活性，选择性和可回收催化剂提供通用的通用平台。