Key Centre for Polymers and Colloids, The University of Sydney, Sydney NSW 2006 (Australia); School of Chemistry, The University of Sydney, Sydney NSW 2006 (Australia).
Chemistry. 2013 Sep 16;19(38):12759-70. doi: 10.1002/chem.201301133. Epub 2013 Aug 12.
The convergence of supramolecular chemistry and polymer science offers many powerful approaches for building functional nanostructures with well-defined dynamic behaviour. Herein we report the efficient "click" synthesis and self-assembly of AB2 - and AB4 -type multitopic porphyrin-polymer conjugates (PPCs). PPCs were prepared using the copper(I)-catalysed azide-alkyne cycloaddition (CuAAC) reaction, and consisted of linear polystyrene, poly(butyl acrylate), or poly(tert-butyl acrylate) arms attached to a zinc(II) porphyrin core via triazole linkages. We exploit the presence of the triazole groups obtained from CuAAC coupling to direct the self-assembly of the PPCs into short oligomers (2-6 units in length) via intermolecular porphyrinatozinc-triazole coordination. By altering the length and grafting density of the polymer arms, we demonstrate that the association constant of the porphyrinatozinc-triazole complex can be systematically tuned over two orders of magnitude. Self-assembly of the PPCs also resulted in a 6 K increase in the glass transition temperature of the bulk material compared to a non-assembling PPC. The modular synthesis and tunable self-assembly of the triazole-linked PPCs thus represents a powerful supramolecular platform for building functional nanostructured materials.
超分子化学和聚合物科学的融合为构建具有明确定义的动态行为的功能纳米结构提供了许多强大的方法。在此，我们报告了 AB2-和 AB4-型多官能团卟啉-聚合物缀合物（PPCs）的有效“点击”合成和自组装。PPCs 是通过铜（I）催化的叠氮-炔环加成（CuAAC）反应制备的，由线性聚苯乙烯、聚（丙烯酸丁酯）或聚（叔丁基丙烯酸酯）臂通过三唑键连接到锌（II）卟啉核上。我们利用 CuAAC 偶联获得的三唑基团的存在，通过分子间卟啉锌-三唑配位将 PPC 自组装成短寡聚物（长度为 2-6 个单元）。通过改变聚合物臂的长度和接枝密度，我们证明卟啉锌-三唑配合物的缔合常数可以在两个数量级范围内进行系统调节。与不进行组装的 PPC 相比，PPC 的自组装还导致块状材料的玻璃化转变温度提高了 6 K。因此，三唑键合的 PPC 的模块化合成和可调自组装代表了构建功能纳米结构材料的强大超分子平台。
