Max-Planck-Institute for Solid State Research, Stuttgart, Germany.
ACS Nano. 2011 Feb 22;5(2):1360-5. doi: 10.1021/nn103058e. Epub 2011 Jan 18.
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.
吸附在 Cu(111)上的不对称分子 4-[反式-2-(吡啶-4-基-乙烯基)]苯甲酸（PVBA）通过扫描隧道显微镜（STM）和密度泛函理论（DFT）进行了表征，以确定亚表面原子层对吸附的影响。与密排表面第一层的 6 重对称性相比，我们发现孤立分子的排列主要遵循 3 重对称性。这种对称性的降低，即分子沿着 ⟨-211⟩轴选择特定的取向，揭示了较低的 Cu 层对分子排列的贡献。我们的计算从静电屏蔽和局部弛豫现象的角度解释了基底与分子的相互作用。
