Stochastic Bullvalene Architecture Modulates Structural Rigidity in π‐Rich Macromolecules
Stochastic Bullvalene Architecture Modulates Structural Rigidity in π‐Rich Macromolecules
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随机 Bullvalene 结构调节富大分子的结构刚度
DOI：
10.1002/anie.202301695
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Golder, Matthew R.
中科院分区：
文献类型：
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作者：
Pomfret, Meredith N.;Sun, Peiguan B.;Huang, Zheng;Freund, Anna C.;Miyoshi, Toshikazu;Golder, Matthew R.
在新型电子产品和纺织品中发现的富π聚合物的合成和加工很困难，因为链刚度导致低溶解度和高热转变。将“变形”分子笼纳入富含 π 的主链中，提供了一组结构扭结，通过独立的价异构体库来调节链结构。在这项工作中，我们报告了（bullvalene-co-亚苯基）的合成和表征，其特征是比典型的刚性棒聚合物聚（对亚苯基）具有更小的持久长度。通过改变聚（对亚苯基）链中牛瓦烯的掺入量（0-50%），我们可以调节热性能和溶液态构象。这些特征是由聚合物主链内的随机牛瓦烯异构体引起的，导致扭结结构。综合而言，牛瓦烯的掺入提供了一种简便的方法来降低富π材料中的结构刚性，而无需伴随结晶。 VT NMR 实验证实这些材料在溶液中保持动态，为未来的刺激响应应用提供了机会。
The synthesis and processing of π‐rich polymers found in novel electronics and textiles is difficult because chain stiffness leads to low solubility and high thermal transitions. The incorporation of “shape‐shifting” molecular cages into π‐rich backbone provides an ensemble of structural kinks to modulate chain architecture via a self‐contained library of valence isomers. In this work, we report the synthesis and characterization of (bullvalene‐co‐phenylene)s that feature smaller persistence lengths than a prototypical rigid rod polymer, poly(p‐phenylene). By varying the amount of bullvalene incorporation within a poly(p‐phenylene) chain (0–50 %), we can tune thermal properties and solution‐state conformation. These features are caused by stochastic bullvalene isomers within the polymer backbone that result in kinked architectures. Synthetically, bullvalene incorporation offers a facile method to decrease structural rigidity within π‐rich materials without concomitant crystallization. VT NMR experiments confirm that these materials remain dynamic in solution, offering the opportunity for future stimuli‐responsive applications.