Self-assembly of periodic bicomponent wires and ribbons
Self-assembly of periodic bicomponent wires and ribbons
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DOI：
10.1002/anie.200604083
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Fasel, Roman
中科院分区：
文献类型：
--
作者：
Canas-Ventura, Marta E.;Xiao, Wende;Fasel, Roman
现代超分子化学的成功很大程度上是基于增强的稳定性和由相对较弱的非共价相互作用（如氢键和金属-配体相互作用）产生的大量不同的杂分子物种。[1]近年来，转移和适应相应的概念，以形成二维（2D）的超分子结构的表面已被深入探讨。[2]二元分子混合物在表征良好的单晶表面上的吸附已经进行了一些研究。[3]在少数情况下，已报道通过氢键相互作用成功形成规则的杂分子物种。[4]然而，到目前为止，在大的长度尺度上控制表面支撑的超分子纳米系统的组织还没有实现。超分子线的有序阵列是最理想的人工结构纳米系统之一，因为它们在未来的设备应用中作为元素构建块的潜力。一维（1D）吸附的超分子结构的增长已经实现，虽然与链长度限制的原子平台的大小。[5]长程有序的一维超分子结构需要模板表面，其中台阶诱导有序而不是破坏它。因此，基于氢键相互作用的特定一维表面支撑的超分子线的规则超晶格的制造依赖于以下两者的合理选择：1）用于一维多位氢键相互作用的互补构件，在40 K的超高真空（UHV）扫描隧道显微镜（STM）研究中，（除非另有说明）沿着金邻位表面的等距和平行台阶形成的双分子线和带。内部以及长程有序的二元线和带的报告。我们使用具有互补端基官能团的分子，这些官能团被设计成形成三个氢键。沉积的两个分子物种上Au（11，12，12）显示，以促进预期的形成三个氢键每个杂分子对，在观察到的两个氢键的ERS组分存款。根据覆盖率，双组分系统产生由一个或两个分子行组成的1D杂分子线的规则超晶格，以及2D超分子带。选择的分子种类是1，4-双-（2，4-二氨基-1，3，5，-三嗪）-苯（BDATB;图1a）和3，4，9，10-二萘嵌苯四羧酸二酰亚胺（PTCDI;图1d）。PTCDI在两个相对侧上具有一个NH氢键供体（D）和两个CO氢键受体（A）的-CO-NH-CO-（酰亚胺）序列，从而产生众所周知的ADA序列。[1f合成BDATB（参见支持信息），以通过分子相对侧上的互补端基官能团（NH-N-NH）提供相互作用选择性，其对应于DAD氢键序列。Au的高适用性（11，12，12）表面作为长程有序分子结构生长的模板是从其大的扩展双周期性衍生而来的：5.8 nm宽的Au（111）阶地被单原子台阶分开，周期性的截断"V"形位错线表明面心立方（fcc）和六方密排（hcp）的边界堆叠域（请参阅支持信息）。[7]Au（111）的低反应活性是由于Au（111）的低反应活性导致的。
The success of modern supramolecular chemistry is largely based on the enhanced stability and enlarged number of distinct heteromolecular species generated from relatively weak, noncovalent interactions such as hydrogen bonding and metal–ligand interactions.[1] In recent years, the transfer and adaptation of the corresponding concepts to the formation of two-dimensional (2D) supramolecular structures on surfaces has been intensively explored.[2] A number of studies on the adsorption of binary molecular mixtures on well-characterized single-crystal surfaces have been performed.[3] In a few cases, the successful formation of regular heteromolecular species through hydrogen-bonding interactions has been reported.[4] The controlled organization of surface-supported supramolecular nanosystems over large length scales, however, has not been achieved so far. Ordered arrays of supramolecular wires are among the most desirable artificially structured nanosystems, because of their potential as elemental building blocks in future device applications. The growth of one-dimensional (1D) adsorbed supramolecular structures has been achieved, albeit with chain lengths restricted to the size of atomic terraces.[5] Longrange ordered 1D supramolecular structures require a template surface where steps induce order instead of destroying it. The fabrication of a regular superlattice of specific 1D surface-supported supramolecular wires based upon hydrogen-bonding interactions thus relies on a rational choice of both 1) the complementary building blocks for 1D multitopic hydrogen-bonding interactions, and 2) an appropriate template surface to guide the long-range growth of the supramolecular structures.Herein we present ultrahigh vacuum (UHV) scanning tunneling microscopy (STM) investigations at 40 K (unless otherwise stated) of bimolecular wires and ribbons that form along the equidistant and parallel steps of an Au vicinal surface. Internal as well as long-range order of the binary wires and ribbons are reported. We use molecules exhibiting complementary end-group functionalities designed to form three hydrogen bonds. Deposition of both molecular species on Au (11, 12, 12) is shown to promote the anticipated formation of three hydrogen bonds per heteromolecular pair, in contrast to the two hydrogen bonds observed for singlecomponent deposits. Depending on coverage, the bicomponent system gives rise to a regular superlattice of 1D heteromolecular wires consisting of one or two molecular rows, as well as 2D supramolecular ribbons. The chosen molecular species are 1, 4-bis-(2, 4-diamino-1, 3, 5,-triazine)-benzene (BDATB; Figure1a) and 3, 4, 9, 10-perylenetetracarboxylic diimide (PTCDI; Figure 1 d). PTCDI exhibits a-CO-NH-CO-(imide) sequence on the two opposite sides with a NH hydrogen-bond donor (D) and two CO hydrogen-bond acceptors (A), thus giving rise to the well-known ADA sequence.[1f, 6] BDATB was synthesized (see the Supporting Information) to provide interaction selectivity by means of complementary end-group functionalities (NH-N-NH) on the opposite sides of the molecules, which correspond to a DAD hydrogen-bonding sequence. The high suitability of the Au (11, 12, 12) surface as a template for the growth of long-range-ordered molecular structures is derived from its large extended double periodicity: 5.8-nmwide Au (111) terraces separated by monoatomic steps as well as periodic truncated “V”-shape discommensuration lines which indicate the border between face-centered cubic (fcc) and hexagonal close-packed (hcp) stacking domains (see the Supporting Information).[7] The low reactivity of Au (111) is …