Physik-Department E20, Technische Universität München, 85748 Garching, Germany.
Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany.
Nat Chem. 2018 Mar;10(3):296-304. doi: 10.1038/nchem.2924. Epub 2018 Jan 22.
Interfacial supramolecular self-assembly represents a powerful tool for constructing regular and quasicrystalline materials. In particular, complex two-dimensional molecular tessellations, such as semi-regular Archimedean tilings with regular polygons, promise unique properties related to their nontrivial structures. However, their formation is challenging, because current methods are largely limited to the direct assembly of precursors, that is, where structure formation relies on molecular interactions without using chemical transformations. Here, we have chosen ethynyl-iodophenanthrene (which features dissymmetry in both geometry and reactivity) as a single starting precursor to generate the rare semi-regular (3.4.6.4) Archimedean tiling with long-range order on an atomically flat substrate through a multi-step reaction. Intriguingly, the individual chemical transformations converge to form a symmetric alkynyl-Ag-alkynyl complex as the new tecton in high yields. Using a combination of microscopy and X-ray spectroscopy tools, as well as computational modelling, we show that in situ generated catalytic Ag complexes mediate the tecton conversion.
界面超分子自组装代表了构建规则和准晶材料的强大工具。特别是复杂的二维分子平铺，如具有正多边形的半正则 Archimedean 平铺，有望具有与其非平凡结构相关的独特性质。然而，它们的形成具有挑战性，因为目前的方法在很大程度上仅限于前体的直接组装，也就是说，结构的形成依赖于分子相互作用，而不使用化学转化。在这里，我们选择了乙炔基碘菲（其在几何形状和反应性上都具有不对称性）作为单个起始前体，通过多步反应在原子平坦的衬底上生成具有长程有序的罕见半正则（3.4.6.4）Archimedean 平铺。有趣的是，各个化学转化通过形成对称的炔基-Ag-炔基配合物而收敛，以高产率作为新的构筑基块。我们使用显微镜和 X 射线光谱工具以及计算建模的组合，表明原位生成的催化 Ag 配合物介导了构筑基块的转化。
