Department of Chemistry, Laboratory of Self-assembling Systems, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
ACS Nano. 2012 Dec 21;6(12):10684-98. doi: 10.1021/nn303868q. Epub 2012 Dec 7.
Controlling the molecular conformation of oligomers on surfaces through noncovalent interactions symbolizes an important approach in the bottom-up patterning of surfaces with nanoscale precision. Here we report on the design, synthesis, and scanning tunneling microscopy (STM) investigation of linear oligoamides adsorbed at the liquid-solid interface. A new class of extended foldamers comprising as many as four turn elements based on a structural design "rule" adapted from a mimic foldamer was successfully synthesized. The self-assembly of these progressively complex oligomeric structures was scrutinized at the liquid-solid interface by employing STM. Submolecularly resolved STM images of foldamers reveal characteristic in-plane folding and self-assembly behavior of these conformationally flexible molecules. The complexity of the supramolecular architectures increases with increasing number of turn elements. The dissimilarity in the adsorption behavior of different foldamers is discussed qualitatively in light of enthalpic and entropic factors. The modular construction of these oligomeric foldamers with integrated functionalities provides a simple, efficient, and versatile approach to surface patterning with molecular precision.
通过非共价相互作用控制表面上低聚物的分子构象，是一种具有纳米级精度的自下而上表面图案化的重要方法。在这里，我们报告了在液体-固界面上吸附的线性寡聚酰胺的设计、合成和扫描隧道显微镜（STM）研究。成功合成了一类新的扩展折叠体，其包含多达四个基于从模拟折叠体中采用的结构设计“规则”的转角元件。通过使用 STM，在液体-固界面处仔细研究了这些逐渐复杂的寡聚物结构的自组装。折叠体的亚分子分辨 STM 图像揭示了这些构象柔性分子的特征面内折叠和自组装行为。随着转角元件数量的增加，超分子结构的复杂性增加。根据焓和熵因素，定性地讨论了不同折叠体的吸附行为的差异。这些具有集成功能的寡聚物折叠体的模块化构建为具有分子精度的表面图案化提供了一种简单、高效和通用的方法。
