Enhancing Conformational Flexibility of Dendronized Triphenylene via Diethylene Glycol Linkers Lowers Transitions of Helical Columnar, Frank-Kasper, and Quasicrystal Phases
Enhancing Conformational Flexibility of Dendronized Triphenylene via Diethylene Glycol Linkers Lowers Transitions of Helical Columnar, Frank-Kasper, and Quasicrystal Phases
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DOI：
10.1016/j.giant.2022.100098
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发表时间：
2022-03
期刊：
影响因子：
7
通讯作者：
M. R. Imam;M. Peterca;Qi Xiao;V. Percec
中科院分区：
文献类型：
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作者：
M. R. Imam;M. Peterca;Qi Xiao;V. Percec
合成了一个通过二甘醇连接子自组装形成树枝状结构的苯并菲（Tp）分子库，并对其自组织结构进行了分析。它们以螺旋柱和球形螺旋自组织冠状构象，产生六方柱状、Frank-Kasper和软准晶组装体。在不存在二甘醇连接体的情况下产生相同的自组织，除了在连接体存在下在较低温度下发生相变和各向同性化温度。柔性二甘醇接头的掺入还诱导螺旋柱中的强π-π堆叠。球形螺旋是螺旋柱的球形扭曲短片段，因此相同的原理决定了六方柱和Frank-Kasper和准晶组装体的热稳定性，除了螺旋柱中超分子主链的长度长得多。这些系统与侧链液晶的比较表明，超分子树枝状聚合物是稳定的扩展超分子骨架构象。这一结果表明，分子工程师的超分子树枝状聚合物的相变自组织冠构象的途径。
A library of triphenylene (Tp) dendronized with self-assembling dendronsviaa diethylene glycol linker was synthesized and the corresponding self-organizations were analyzed. They self-organizeviaa crown conformation in helical columns and spherical helices that produce hexagonal columnar, Frank-Kasper and soft quasicrystal assemblies. The same self-organizations are produced in the absence of the diethylene glycol linker except that the phase transitions and isotropization temperatures occur at lower temperatures in the presence of the linker. The incorporation of the flexible diethylene glycol linker induces also strong π-π stacking in helical columns. Spherical helices are spherical distorted short fragments of helical columns and therefore the same principles determine the thermal stability of the hexagonal columnar and of Frank-Kasper and quasicrystal assemblies except that the length of the supramolecular backbone is much longer in helical columns. A comparison of these systems with side-chain liquid crystals indicates that supramolecular dendrimers are stabilized by extended supramolecular backbone conformations. This result suggests pathways to molecularly engineer phase transitions of supramolecular dendrimers self-organized from crown conformations.