Park Kwang-Won, Adisoejoso Jinne, Plas Jan, Hong Jongin, Müllen Klaus, De Feyter Steven
Division of Molecular Imaging and Photonics, Department of Chemistry, Katholieke Universiteit Leuven , Celestijnenlaan 200 F, 3001 Leuven, Belgium.
Langmuir. 2014 Dec 23;30(50):15206-11. doi: 10.1021/la5040849. Epub 2014 Dec 8.
The engineering of two-dimensional crystals by physisorption-based molecular self-assembly at the liquid-solid interface is a powerful method to functionalize and nanostructure surfaces. The formation of high-symmetry networks from low-symmetry building blocks is a particularly important target. Alkylated isophthalic acid (ISA) derivatives are early test systems, and it was demonstrated that to produce a so-called porous hexagonal packing of plane group p6, i.e., a regular array of nanowells, either short alkyl chains or the introduction of bulky groups within the chains were mandatory. After all, the van der Waals interactions between adjacent alkyl chains or alkyl chains and the surface would dominate the ideal hydrogen bonding between the carboxyl groups, and therefore, a close-packed lamella structure (plane group p2) was uniquely observed. In this contribution, we show two versatile approaches to circumvent this problem, which are based on well-known principles: the "concentration in control" and the "guest-induced transformation" methods. The successful application of these methods makes ISA suitable building blocks to engineer a porous pattern, in which the distance between the pores can be tuned with nanometer precision.
通过基于物理吸附的分子自组装在液固界面制备二维晶体是一种使表面功能化和纳米结构化的有力方法。由低对称性结构单元形成高对称性网络是一个特别重要的目标。烷基化间苯二甲酸（ISA）衍生物是早期的测试体系，结果表明，要产生所谓的平面群p6的多孔六边形堆积，即纳米孔的规则阵列，短烷基链或在链中引入大体积基团是必不可少的。毕竟，相邻烷基链之间或烷基链与表面之间的范德华相互作用将主导羧基之间理想的氢键作用，因此，唯一观察到的是密堆积层状结构（平面群p2）。在本论文中，我们展示了两种基于熟知原理来规避此问题的通用方法：“控制浓度”法和“客体诱导转变”法。这些方法的成功应用使ISA成为构建多孔图案的合适结构单元，其中孔间距可精确到纳米级进行调节。
