Self-assembly and conformation of tetrapyridyl-porphyrin molecules on Ag(111)
Self-assembly and conformation of tetrapyridyl-porphyrin molecules on Ag(111)
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DOI：
10.1063/1.2194541
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发表时间：
2006-05-21
影响因子：
4.4
通讯作者：
Barth, J. V.
中科院分区：
文献类型：
--
作者：
Auwarter, W.;Weber-Bargioni, A.;Barth, J. V.
用低温扫描隧道显微镜(STM)研究了四氢吡啶基卟啉(TPyP)分子在Ag(111)表面的超分子有序性。在宽衬底温度范围内的气相沉积表明，TPyP分子很容易扩散和自组装成大的、高度有序的手性结构域。我们确定了两个镜像对称的单胞，每个单胞包含两个不同取向的分子。通过对各自排列的分析，得出结论：侧向分子间相互作用控制着层的堆积，而其取向是由与衬底的耦合引起的。这一发现得到了分子力学计算的证实。在15K下记录的高分辨率STM图像允许直接识别分子内特征。这使得确定TPyP在Ag(111)面上的分子构象成为可能。吡啶基团交替地旋转出卟啉平面60度角。(C)2006年美国物理研究所。
We present a low-temperature scanning tunneling microscopy (STM) study on the supramolecular ordering of tetrapyridyl-porphyrin (TPyP) molecules on Ag(111). Vapor deposition in a wide substrate temperature range reveals that TPyP molecules easily diffuse and self-assemble into large, highly ordered chiral domains. We identify two mirror-symmetric unit cells, each containing two differently oriented molecules. From an analysis of the respective arrangement it is concluded that lateral intermolecular interactions control the packing of the layer, while its orientation is induced by the coupling to the substrate. This finding is corroborated by molecular mechanics calculations. High-resolution STM images recorded at 15 K allow a direct identification of intramolecular features. This makes it possible to determine the molecular conformation of TPyP on Ag(111). The pyridyl groups are alternately rotated out of the porphyrin plane by an angle of 60 degrees. (c) 2006 American Institute of Physics.