Honda Kento, Tahara Kazukuni
Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
Chemistry. 2024 May 23;30(29):e202400926. doi: 10.1002/chem.202400926. Epub 2024 Apr 30.
The molecular-level scrutinization of on-surface tiling garners considerable interest among scientists. Herein, we demonstrate molecular-level heptagonal tiling using the self-assembly of a heptagonal meta-phenylene-ethynylene macrocycle featuring 14 long alkoxy substituents at the liquid-graphite interface using scanning tunneling microscopy. This heptagonal macrocycle produces an antiparallel pattern at the 1-phenyloctane-graphite interface through van der Waals interactions between the alkoxy chains. This pattern resembles the densely packed pattern of heptagonal tiles, albeit with variations in the orientations and spacing of heptagonal cores owing to intermolecular interactions between the alkoxy chains. Conversely, at the 1,2,4-trichlorobenzene-graphite interface, the heptagonal molecule forms an oblique pattern composed of four independent molecular orientations. This phenomenon arises from core distortion induced by the coadsorption of the solvent molecules within the intrinsic macrocyclic pores. This study elucidates the design strategy - specifically, the choice of heptagonal molecular building block - for heptagonal tiling and fills a crucial gap in the field of two-dimensional crystal engineering.
表面平铺的分子水平研究引起了科学家们的广泛关注。在此，我们使用扫描隧道显微镜，在液-石墨界面上通过具有14个长烷氧基取代基的七边形间亚苯基乙炔大环的自组装，展示了分子水平的七边形平铺。这种七边形大环通过烷氧基链之间的范德华相互作用，在1-苯基辛烷-石墨界面产生反平行图案。尽管由于烷氧基链之间的分子间相互作用，七边形核心的取向和间距存在变化，但这种图案类似于七边形瓷砖的密集堆积图案。相反，在1,2,4-三氯苯-石墨界面，七边形分子形成由四个独立分子取向组成的倾斜图案。这种现象源于溶剂分子在固有大环孔内共吸附引起的核心畸变。本研究阐明了七边形平铺的设计策略，特别是七边形分子构建块的选择，并填补了二维晶体工程领域的一个关键空白。
