Zoppi Laura, Stöckl Quirin, Mairena Anaïs, Allemann Oliver, Siegel Jay S, Baldridge Kim K, Ernst Karl-Heinz
Empa, Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129, 8600 Dübendorf, Switzerland.
Department of Chemistry, University of Zurich , Winterthurerstrasse 190, 8057 Zürich, Switzerland.
J Phys Chem B. 2018 Jan 18;122(2):871-877. doi: 10.1021/acs.jpcb.7b06967. Epub 2017 Sep 26.
Modification of metal electrode surfaces with functional organic molecules is an important step toward organic electronics. The interaction of the buckybowl indenocorannulene with a Cu(111) surface and the two-dimensional self-assembly on the same surface was studied by means of scanning tunneling microscopy and dispersion-enabled density functional theory. Based on the conjecture of maximizing van der Waals interaction with the surface one would expect the indeno group to be aligned parallel to the surface. Theoretical investigations predict a nonparallel arrangement with the benzo ring of the indeno group located higher above the surface than the bowl rim connected to the indeno group. This adsorbate geometry is due to strong electronic interaction between molecule and surface, including substantial Pauli repulsion. The long-range ordered monolayer shows differences for two molecules of the unit cell in scanning tunneling microscopy contrast, suggesting either different polar alignments, and therefore a different tilt of the indeno group, or occupation of different adsorption sites.
用功能性有机分子修饰金属电极表面是迈向有机电子学的重要一步。通过扫描隧道显微镜和色散增强密度泛函理论研究了巴基碗茚并蔻与Cu(111)表面的相互作用以及在同一表面上的二维自组装。基于使与表面的范德华相互作用最大化的推测，人们预期茚基会与表面平行排列。理论研究预测，茚基的苯环位于表面上方比与茚基相连的碗边更高的位置，呈现出非平行排列。这种吸附质几何结构是由于分子与表面之间强烈的电子相互作用，包括大量的泡利排斥。在扫描隧道显微镜对比度下，长程有序单分子层在晶胞的两个分子之间显示出差异，这表明要么是不同的极性排列，因此茚基有不同的倾斜度，要么是占据了不同的吸附位点。
