Breaking Symmetry toward Nonspherical Janus Particles Based on Polyhedral Oligomeric Silsesquioxanes: Molecular Design, "Click" Synthesis, and Hierarchical Structure
Breaking Symmetry toward Nonspherical Janus Particles Based on Polyhedral Oligomeric Silsesquioxanes: Molecular Design, "Click" Synthesis, and Hierarchical Structure
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DOI：
10.1021/ja202906m
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发表时间：
2011-07-20
影响因子：
15
通讯作者：
Cheng, Stephen Z. D.
中科院分区：
文献类型：
--
作者：
Li, Yiwen;Zhang, Wen-Bin;Cheng, Stephen Z. D.
设计、合成和自组装了一系列精确定义的、非球形的、多面体低聚倍半硅氧烷（POSS）分子Janus粒子。该合成的目的是通过使用硫醇-烯化学有效地在POSS笼之一上安装多功能性来实现“点击”哲学。在这种情况下，几何和化学对称性都被打破，创造了Janus特征。这些颗粒在本体中自组织成分级有序的超分子结构。例如，在一个POSS上具有异丁基基团并且在另一个上具有羧基基团的Janus颗粒自组装成具有每个颗粒的头对头、尾对尾排列的双层结构，其进一步组织成三维正交晶格。虽然在层中的有序结构在加热时通过一级转变丢失，但双层结构始终存在。这项研究提供了一个定义明确的分子Janus粒子的模型系统，用于一般理解其在凝聚态下的自组装和分级结构的形成。
The design, synthesis, and self-assembly of a series of precisely defined, nonspherical, polyhedral oligomeric silsesquioxane (POSS)-based molecular Janus particles are reported. The synthesis aims to fulfill the "click" philosophy by using thiol-ene chemistry to efficiently install versatile functionalities on one of the POSS cages. In such away, both the geometrical and chemical symmetries were broken to create the Janus feature. These particles self-organize into hierarchically ordered supramolecular structures in the bulk For example, the Janus particle with isobutyl groups on one POSS and carboxylic groups on the other self-assembles into a bilayered structure with head-to-head, tail-to-tail arrangements of each particle, which further organize into a three-dimensional orthorhombic lattice. While the ordered structure in the layers was lost upon heating via a first-order transition, the bilayered structure persisted throughout This study provides a model system of well-defined molecular Janus particles for the general understanding of their self-assembly and hierarchical structure formation in the condensed state.