Impact of Positional Isomerism on Pathway Complexity in Aqueous Media
Impact of Positional Isomerism on Pathway Complexity in Aqueous Media
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DOI：
10.1002/anie.201911531
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发表时间：
2020-02-03
影响因子：
16.6
通讯作者：
Fernandez, Gustavo
中科院分区：
文献类型：
--
作者：
Helmers, Ingo;Shen, Bowen;Fernandez, Gustavo
近年来，由于其在分子组装过程优化中的相关性，途径复杂性已成为一个重要的话题，这通常需要精确的样品制备方案。或者，竞争性聚集途径可以通过分子设计来控制，这主要依赖于结构单元的几何变化。然而，理解如何通过分子设计来控制途径复杂性仍然是难以捉摸的，需要新的方法。在此，我们利用位置异构作为一种新的分子设计策略，在水溶液自组装的途径控制。我们比较了两种羧基官能化的两亲性BODIPY染料的自组装，其仅在官能团的相对位置上不同。在2-位的羧基的位置使有效的成对氢键相互作用成为一个单一的热力学物种，而内消旋取代诱导途径的复杂性，由于竞争的疏水和氢键相互作用。我们的研究结果表明，在水溶液自组装的路径控制的位置工程的重要性。
Pathway complexity has become an important topic in recent years due to its relevance in the optimization of molecular assembly processes, which typically require precise sample preparation protocols. Alternatively, competing aggregation pathways can be controlled by molecular design, which primarily rely on geometrical changes of the building blocks. However, understanding how to control pathway complexity by molecular design remains elusive and new approaches are needed. Herein, we exploit positional isomerism as a new molecular design strategy for pathway control in aqueous self-assembly. We compare the self-assembly of two carboxyl-functionalized amphiphilic BODIPY dyes that solely differ in the relative position of functional groups. Placement of the carboxyl group at the 2-position enables efficient pairwise H-bonding interactions into a single thermodynamic species, whereas meso-substitution induces pathway complexity due to competing hydrophobic and hydrogen bonding interactions. Our results show the importance of positional engineering for pathway control in aqueous self-assembly.