Macleod J M, Ivasenko O, Perepichka D F, Rosei F
Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, Université du Québec, 1650 Boulevard Lionel-Boulet, Varennes, QC, J3X 1S2, Canada.
Nanotechnology. 2007 Oct 24;18(42):424031. doi: 10.1088/0957-4484/18/42/424031. Epub 2007 Sep 21.
Trimesic acid (TMA) and alcohols were recently shown to self-assemble into a stable, two-component linear pattern at the solution/highly oriented pyrolytic graphite (HOPG) interface. Away from equilibrium, the TMA/alcohol self-assembled molecular network (SAMN) can coexist with pure-TMA networks. Here, we report on some novel characteristics of these non-equilibrium TMA structures, investigated by scanning tunneling microscopy (STM). We observe that both the chicken-wire and flower-structure TMA phases can host 'guest' C(60) molecules within their pores, whereas the TMA/alcohol SAMN does not offer any stable adsorption sites for the C(60) molecules. The presence of the C(60) molecules at the solution/solid interface was found to improve the STM image quality. We have taken advantage of the high-quality imaging conditions to observe unusual TMA bonding geometries at domain boundaries in the TMA/alcohol SAMN. Boundaries between aligned TMA/alcohol domains can give rise to doubled TMA dimer rows in two different configurations, as well as a tripled-TMA row. The boundaries created between non-aligned domains can create geometries that stabilize TMA bonding configurations not observed on surfaces without TMA/alcohol SAMNs, including small regions of the previously predicted 'super flower' TMA bonding geometry and a tertiary structure related to the known TMA phases. These structures are identified as part of a homologic class of TMA bonding motifs, and we explore some of the reasons for the stabilization of these phases in our multicomponent system.
均苯三甲酸（TMA）和醇类最近被证明在溶液/高度取向热解石墨（HOPG）界面自组装成稳定的双组分线性图案。在远离平衡的情况下，TMA/醇自组装分子网络（SAMN）可以与纯TMA网络共存。在这里，我们报告这些非平衡TMA结构的一些新特性，通过扫描隧道显微镜（STM）进行研究。我们观察到，铁丝网状和花状结构的TMA相在其孔隙中都可以容纳“客体”C(60)分子，而TMA/醇SAMN没有为C(60)分子提供任何稳定的吸附位点。发现在溶液/固体界面存在C(60)分子可提高STM图像质量。我们利用高质量的成像条件，观察了TMA/醇SAMN中畴界处异常的TMA键合几何结构。对齐的TMA/醇畴之间的边界可以产生两种不同构型的双倍TMA二聚体行，以及三倍TMA行。未对齐畴之间形成的边界可以产生稳定的TMA键合构型，这些构型在没有TMA/醇SAMN的表面上未观察到，包括先前预测的“超级花”TMA键合几何结构的小区域以及与已知TMA相相关的三级结构。这些结构被确定为TMA键合基序同源类别的一部分，并且我们探讨了在我们的多组分系统中这些相稳定的一些原因。
