分子模板可控构筑纳米组装结构的STM研究

发布时间：2018-08-20 12:02

【摘要】：摘要：随着微电子器件的不断小型化,利用分子模板构筑和调控表面纳米结构对构建分子器件具有重要的意义。本论文主要以扫描隧道显微技术(STM)为研究手段,并结合密度泛函理论计算,研究了二维超分子网格对有机功能分子组装体的可控构筑,主要内容如下：一、分子模板可提高表面光化学反应的效率。反式1,2-二(4-吡啶基)乙烯(4,4'-bpe)和间苯二酸(iso-pa)按照化学计量比1：1合成2(4,4'-bpe)-2(iso-pa)。利用苯三氧十一酸(TCDB)分子自组装形成的二维超分子网格作为分子模板,吸附2(4,4'-bpe)-2(iso-pa)作为客体分子,构筑了二维主客体体系。在紫外光照射下,发现4,4'-bpe先进行了反式向顺式结构的转变,进而发生了光聚合反应。同时,我们将4,4'-bpe-iso-pa作为目标分子,研究其单独在石墨表面自组装结构和发生光化学反应的效率,发现只有少数几个4,4'-bpe发生了光聚合反应。通过STM实验结果和光谱实验数据表明,这种高效率的光聚合产物生成归因于分子模板对客体分子构型的调控。这一结果为表面光化学反应基本问题的研究提供了一种思路。二、分子模板对客体分子选择性响应,构筑和调控分子阵列。第一,将客体分子蔻(COR)引入到偶氮四羧酸(NN4A)和1,2-二(4-吡啶基)乙烯(4,4'-bpe)构建的柔性四边形网格结构,分子组装结构发生重构形成了NN4A/COR主客体体系。密度泛函理论计算表明,NN4A/COR结构的热力学相对稳定。第二,研究了以TCDB为分子模板,轴向酞菁硅衍生物为客体分子,吡啶类化合物成功调控轴向酞菁硅衍生物的组装结构,由于目标分子结构的特点,实现了在纳米模板分子侧立于石墨表面的吸附行为研究。第三,利用六元和八元刚性环状化合物作为超分子模板,利用两个环状分子的空腔构型和尺寸大小等特点,与富勒烯分子形成不同种类的阵列结构。
[Abstract]:Absrtact: with the miniaturization of microelectronic devices, it is of great significance to construct molecular devices by using molecular templates to construct and regulate surface nanostructures. In this thesis, the controllable construction of two dimensional supramolecular meshes for organic functional molecular assemblies is studied by scanning tunneling microscopy (STM) and density functional theory (DFT). The main contents are as follows: 1. Molecular template can improve the efficiency of surface photochemical reaction. The synthesis of 2 (4h4mg-bpe) -2 (iso-pa) at 1:1 from trans 1hm2- bis (4-pyridyl) ethylene (4C4BPE) and isophthalic acid (iso-pa) was studied. A two-dimensional host and guest system was constructed by using two-dimensional supramolecular meshes formed by self-assembly of (TCDB) molecules as template and adsorption of 2 (4 (4N) -bpe) -2 (iso-pa) as guest molecules. Under UV irradiation, it was found that the conversion of the trans structure to cis structure was first carried out, and then the photopolymerization reaction took place. At the same time, we study the self-assembly structure and the efficiency of photochemical reaction on the surface of graphite by using 4C4Pe -bpe-iso-pa as the target molecule. It is found that only a small number of 4PE-BPE have been photopolymerized. The results of STM and spectroscopic experiments show that the high efficiency of the photopolymerization products is attributed to the regulation of the guest molecular configuration by the molecular template. This result provides a way to study the basic problems of surface photochemical reaction. Secondly, molecular templates selectively respond to guest molecules and construct and regulate molecular arrays. Firstly, the guest molecule (COR) was introduced into the flexible quadrilateral grid structure constructed by NN4A and 1C _ 2-bis (4-pyridyl) ethylene, and the molecular assembly structure was reconstructed to form the host and guest system of NN4A/COR. The density functional theory (DFT) calculation shows that the thermodynamic stability of NN4A / cor structure is relatively stable. Secondly, using TCDB as molecular template and axial phthalocyanine silicon derivative as guest molecule, pyridine compounds successfully regulate the assembly structure of axial phthalocyanine silicon derivative, because of the characteristics of the target molecular structure. The adsorption behavior of graphite on the side of nano-template molecule was studied. Thirdly, using the six and eight member rigid ring compounds as supramolecular templates, using the cavity configuration and size of the two ring molecules, different kinds of array structures are formed with fullerene molecules.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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