Selective assembly on a surface of supramolecular aggregates with controlled size and shape
Selective assembly on a surface of supramolecular aggregates with controlled size and shape
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DOI：
10.1038/35098059
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发表时间：
2001-10-11
期刊：
影响因子：
64.8
通讯作者：
Mashiko, S
中科院分区：
文献类型：
--
作者：
Yokoyama, T;Yokoyama, S;Mashiko, S
实现具有先进功能的基于分子的微型器件需要开发新的有效方法，用于将分子构建块组合成所需的功能结构，理想情况下这些结构支撑在合适的基底上（1-4）。超分子聚集自发发生，如果利用选择性和定向非共价相互作用，可以导致受控结构。但是这种选择性的超分子组装几乎只产生晶体或溶解的结构（5）;相反，被吸收的分子自组装成更大的结构（6-8）还没有通过控制选择性的分子间相互作用来指导。在这里，我们报告的表面支撑的超分子结构的形成，其大小和聚集模式是合理的控制，通过调整单个吸附分子之间的非共价相互作用。使用低温扫描隧道显微镜，我们表明，取代卟啉分子吸附在金表面形成单体，三聚体，四聚体或扩展的线状结构。我们发现，每个结构对应于一个可预测的方式的几何和化学性质的卟啉取代基，介导的相互作用，个别吸附分子之间。我们的研究结果表明，能够参与定向非共价相互作用的官能团的仔细放置将允许合理的设计和构建广泛的超分子结构吸收到表面。
The realization of molecule-based miniature devices with advanced functions requires the development of new and efficient approaches for combining molecular building blocks into desired functional structures, ideally with these structures supported on suitable substrates(1-4). Supramolecular aggregation occurs spontaneously and can lead to controlled structures if selective and directional non-covalent interactions are exploited. But such selective supramolecular assembly has yielded almost exclusively crystals or dissolved structures(5); the self-assembly of absorbed molecules into larger structures(6-8), in contrast, has not yet been directed by controlling selective intermolecular interactions. Here we report the formation of surface-supported supramolecular structures whose size and aggregation pattern are rationally controlled by tuning the non-covalent interactions between individual absorbed molecules. Using low-temperature scanning tunnelling microscopy, we show that substituted porphyrin molecules adsorbed on a gold surface form monomers, trimers, tetramers or extended wire-like structures. We rnd that each structure corresponds in a predictable fashion to the geometric and chemical nature of the porphyrin substituents that mediate the interactions between individual adsorbed molecules. Our findings suggest that careful placement of functional groups that are able to participate in directed noncovalent interactions will allow the rational design and construction of a wide range of supramolecular architectures absorbed to surfaces.