Lateral manipulation for the positioning of molecular guests within the confinements of a highly stable self-assembled organic surface network
Lateral manipulation for the positioning of molecular guests within the confinements of a highly stable self-assembled organic surface network
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DOI：
10.1002/smll.200700099
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发表时间：
2007-08-01
期刊：
影响因子：
13.3
通讯作者：
Jung, Thomas A.
中科院分区：
文献类型：
--
作者：
Stohr, Meike;Wahl, Markus;Jung, Thomas A.
分子水平的结构层次可以通过相互作用能的层次来确定；换句话说，为了分几步生成复杂结构，需要相互作用能量的显着差异。 [1]第一结构水平的组装需要涉及分子构件之间的强相互作用，而其随后的延伸而不需修改支架则可以在较弱的键合力的基础上方便地实现。这既适用于溶液和空气/真空中的超分子组装体，也适用于固定或空间受限的结构。 [2]在这里，我们提供了这样一个基于具有前所未有的热稳定性的表面有机网络结构的例子。晶体表面已成为生成此类空间可寻址结构的初始支架，[3] 并且单个原子和分子的操纵已通过扫描探针显微镜实现。 [4, 5] 最近，报道了对具有多个甚至部分可寻址自由度的大分子 [6] 的受控横向操纵的广泛研究。 [7]扫描隧道显微镜 (STM) 尖端甚至用于诱导化学反应，[8] 例如乌尔曼反应。 [9]我们最近报道了通过 4, 9-二氨基苝醌-3, 10-二亚胺 (DPDI)[10] 在 CuACHTUNGTRENNUNG (111) 表面上热脱氢生成的高度稳定的六边形分子网络的形成 （方案1）。[11]通过热活化，这些分子形成自动互补的氢键供体/受体，它们在表面网络的形成中预先定位自身。高度规则的蜂窝结构[12]与Cu基底相当（以pACHTUNGTRENNUNG（10 10）超晶格的形式，晶格常数为2.55 nm），并且由于有机分子和表面金属原子之间的强π键以及分子之间的共振辅助H键的结合而具有热稳定性（高达> 3008C）。由于其结构规律性和稳定性，这种表面结构为功能性分层聚集体的组装提供了理想的起点。网络中的六边形“孔”为其他分子的局部沉积和固定提供了机会（方案1）。图 1 显示了随后在环境温度下沉积在先前制备的蜂窝网络上的 C60 和八乙基卟啉锌 (ZnOEP) 复合物在 77 K 下的 STM 图像。 C60 和 ZnOEP 均被捕获并统计分布在网络中。在这样的低温下——
Structural hierarchies at the molecular level can be determined by the hierarchies of interaction energies; in other words, for the generation of complex structures in several steps, significant differences in the interaction energetics are required.[1] The assembly of the first structural level needs to involve strong interactions between the molecular building blocks, whereas its subsequent extension without modification of the scaffold is conveniently ACHTUNGTRENNUNGachieved on the basis of weaker bonding forces. This applies both to supramolecular assemblies in solution and in air/vacuum and to fixed or spatially confined structures.[2] Herein, we provide such an example based on a surface organic network structure of unprecedented thermal stability. Crystal surfaces have served as initial scaffolds for the generation of such spatially addressable structures,[3] and the manipulation of single atoms and molecules has been ACHTUNGTRENNUNGachieved by scanning probe microscopy.[4, 5] More recently, extensive investigations into the controlled lateral manipulation of large molecules [6] possessing multiple and even partially addressable degrees of freedom have been reported.[7] The scanning tunneling microscopy (STM) tip was even used to induce chemical reactions,[8] for example, the Ullman reaction.[9]We recently reported the formation of a highly stable, hexagonal molecular network generated by thermal dehydrogenation of 4, 9-diaminoperylene-quinone-3, 10-diimine (DPDI)[10] on a CuACHTUNGTRENNUNG (111) surface (Scheme 1).[11] By thermal activation, these molecules form autocomplementary hydrogen-bond donors/acceptors, which preposition themselves in the formation of the surface network. The highly regular honeycomb structure [12] is commensurate with the Cu substrate (in the form of a pACHTUNGTRENNUNG (10 10) superlattice with a lattice constant of 2.55 nm) and is thermally very stable (up to> 3008C) as a consequence of a combination of strong π bonding between the organic molecules and the surface metal atoms and resonance-assisted H bonding between the molecules. Due to its structural regularity and stability, this surface structure provides the ideal starting point for the assembly of functional hierarchical aggregates. The hexagonal “holes” in the network provide the opportunity for the local deposition and fixation of other molecules (Scheme 1). Figure 1 shows an STM image at 77 K of C60 and zinc octaethylporphyrin (ZnOEP) complexes subsequently deposited at ambient temperature on the previously prepared honeycomb network. Both C60 and ZnOEP are trapped and statistically distributed in the network. At this low tempera-