Abstract In this paper we present a DFT investigation on the structure and energetics of (√3 × 2√3)R30° high coverage SAMs of n-alkanethiols up to twelve carbon atoms on a clean Au(111) surface. The surface was found to be more reconstructed for longer chains, although a surface reconstruction plateau was reached for decanethiol SAMs. The geometry was suggested to be dictated by steric effects and van der Waals interactions between the adsorbates resulting in a specific adsorption configuration. Furthermore, the increasing adsorption energy per thiol molecule is due to the increasing van der Waals forces between the adsorbates. In conclusion a more stable monolayer was obtained with increasing adsorbate chain length. In other words a subtle balance between interchain interactions and surface reconstruction is at the origin of the alkylthiol/Au(111) self-assembled monolayer geometry.

中文翻译：

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烷基硫醇/金（111）自组装单层几何结构起源处链间相互作用和表面重建之间的微妙平衡

摘要 在本文中，我们对清洁 Au(111) 表面上多达 12 个碳原子的正链烷硫醇的 (√3 × 2√3)R30° 高覆盖率 SAM 的结构和能量学进行了 DFT 研究。尽管对于癸硫醇 SAM 达到了表面重建平台，但发现更长的链更容易重建表面。建议几何形状由空间效应和吸附质之间的范德华相互作用决定，导致特定的吸附构型。此外，每个硫醇分子的吸附能增加是由于被吸附物之间的范德华力增加。总之，随着吸附物链长度的增加，获得了更稳定的单层。