Influence of Subsurface Layers on the Adsorption of Large Organic Molecules on Close-Packed Metal Surfaces

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• 作者：Robin Ohmann ; Giacomo Levita ; Lucia Vitali ; Alessandro De Vita ; Klaus Kern
• 刊名：ACS Nano
• 出版年：2011
• 出版时间：February 22, 2011
• 年：2011
• 卷：5
• 期：2
• 页码：1360-1365
• 全文大小：830K
• 年卷期：0
• ISSN：1936-086X

文摘

The asymmetric molecule 4-[trans-2-(pyrid-4-yl-vinyl)] benzoic acid (PVBA) adsorbed on Cu(111) is characterized by scanning tunneling microscopy (STM) and density functional theory (DFT) to determine the influence of subsurface atomic layers on the adsorption. In contrast to the 6-fold symmetry of the first atomic layer of close-packed surfaces, we find that the arrangement of the isolated molecules follows predominantly a 3-fold symmetry. This reduction in symmetry, where the molecule selects a specific orientation along the ⟨−211⟩ axes, reveals the contribution of lower-lying Cu layers to the molecular arrangement. Our calculations rationalize the interaction of the substrate with the molecule in terms of electrostatic screening and local relaxation phenomena.