Two-dimensional self-assembly of star-shaped 2,4,6-tris(4-bromophenyl)-1,3,5-triazine (BPT) molecule is investigated both on highly oriented pyrolytic graphite (HOPG) and single-layer graphene (SLG) grown on a polycrystalline Cu foil. Scanning tunneling microscopy (STM) reveals that this molecule can form different self-assembling structures on these two different surfaces. On the basis of high-resolution STM images, we find that BPT molecules can form compact and loose assembly patterns with different packing densities on HOPG surface and a porous structure with hexagonal-like cavities on SLG surface. A combination of STM and density functional theory calculations elucidates the interplay of molecule–molecule and molecule–substrate interactions on the assembling behavior on both substrates.

中文翻译：

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2,4,6-Tris（4-溴苯基）-1,3,5-三嗪超分子自组装对石墨和石墨烯的底物效应

在高取向热解石墨（HOPG）和单层石墨烯上研究了星形2,4,6-三（4-溴苯基）-1,3,5-三嗪（BPT）分子的二维自组装（SLG）生长在多晶铜箔上。扫描隧道显微镜（STM）表明，该分子可以在这两个不同的表面上形成不同的自组装结构。在高分辨率STM图像的基础上，我们发现BPT分子可以在HOPG表面上形成具有不同堆积密度的紧凑且松散的组装模式，而在SLG表面上具有六角形腔的多孔结构。STM和密度泛函理论计算的结合阐明了分子-分子和分子-底物相互作用对两种底物组装行为的相互作用。