伦敦色散力引导[121]四甲基笼烷分子的表面自组装。

London Dispersion Directs On-Surface Self-Assembly of [121]Tetramantane Molecules.

机构信息

Institute of Applied Physics, Justus-Liebig University , Heinrich-Buff-Ring 16, 35392 Giessen, Germany.

Institute of Organic Chemistry, Justus-Liebig University , Heinrich-Buff-Ring 17, 35392 Giessen, Germany.

出版信息

ACS Nano. 2017 Sep 26;11(9):9459-9466. doi: 10.1021/acsnano.7b05204. Epub 2017 Sep 1.

DOI:10.1021/acsnano.7b05204

PMID:28846392

Abstract

London dispersion (LD) acts between all atoms and molecules in nature, but the role of LD interactions in the self-assembly of molecular layers is still poorly understood. In this study, direct visualization of single molecules using atomic force microscopy with CO-functionalized tips revealed the exact adsorption structures of bulky and highly polarizable [121]tetramantane molecules on Au(111) and Cu(111) surfaces. We determined the absolute molecular orientations of the completely sp-hybridized tetramantanes on metal surfaces. Moreover, we demonstrate how LD drives this on-surface self-assembly of [121]tetramantane hydrocarbons, resulting in the formation of a highly ordered 2D lattice. Our experimental findings were underpinned by a systematic computational study, which allowed us to quantify the energies associated with LD interactions and to analyze intermolecular close contacts and attractions in detail.

摘要

伦敦色散（LD）作用于自然界中的所有原子和分子，但 LD 相互作用在分子层自组装中的作用仍未被很好地理解。在这项研究中，使用 CO 功能化尖端的原子力显微镜对单个分子进行直接可视化，揭示了庞大且高极化的[121]四烷分子在 Au(111)和 Cu(111)表面的精确吸附结构。我们确定了完全 sp 杂化的四烷在金属表面上的绝对分子取向。此外，我们展示了 LD 如何驱动[121]四烷烃在表面上的自组装，从而形成高度有序的 2D 晶格。我们的实验结果得到了系统计算研究的支持，这使我们能够量化与 LD 相互作用相关的能量，并详细分析分子间的近距离接触和吸引力。