Indenofluorene, which consists of a 6-5-6-5-6 fused-ring structure, is a semiconducting molecule with possible applications in optoelectronic devices. Bulk crystal structures, molecular front orbitals, and on-surface polymerized indenofluorene have recently been studied, but self-assembled structures on the surface have not yet been reported. Here, we report the array structure of 2,8-dibromoindeno[1,2-b]fluorene-6,12-dione on Au(111) studied using scanning tunneling microscopy. We proposed an alternating-tread stair structure as the molecular model for the monolayer molecular islands, which show strong shape anisotropy. The model can be explained by four O⋅⋅⋅H hydrogen bonds and one Br⋅⋅⋅Br halogen bond per molecule, as supported by density functional theory calculations. Although they prefer intermixed heteroprochiral structures in bulk layers, our study shows that these molecules can form phase-separated homoprochiral structures on the surface, leading to potential applications in molecular chiral separation.

中文翻译：

---

由 Au(111) 上的氢和卤素键稳定的相分离茚并芴阵列

茚并芴由 6-5-6-5-6 稠环结构组成，是一种半导体分子，可用于光电器件。最近研究了块状晶体结构、分子前轨道和表面聚合茚并芴，但尚未报道表面上的自组装结构。在这里，我们报告了使用扫描隧道显微镜研究的 Au(111) 上 2,8-二溴茚并[1,2-b]芴-6,12-二酮的阵列结构。我们提出了一种交替的阶梯结构作为单层分子岛的分子模型，它表现出强烈的形状各向异性。该模型可以通过密度泛函理论计算支持的每个分子的四个 O⋅⋅⋅H 氢键和一个 Br⋅⋅⋅Br 卤素键来解释。尽管他们更喜欢体层中混合的异手性结构，