Construction of Artificial Supraniolecular Systems Capable of being Responsive to External Stimuli

本研究项目旨在构建能够对化学和物理等外部刺激作出反应的人工超分子系统。本项目所取得的成果总结如下：1。设计并合成了人工糖受体。受体分别选择性识别核糖、脱氧核糖和葡萄糖，并采用底物诱导构象组织的识别策略（诱导拟合机制）。受体将天然糖溶解到低极性溶剂中，如CHCl_3。利用受体对糖类进行选择性转化的过程正在进行中。我们开发了一类新的水溶性环烷，pyrenophes，能够通过疏水相互作用识别核碱基。pyrenophanes仅显示准分子发射，并且在识别核碱基时发射被淬灭。我们现在正在研究芘与DNA之间的相互作用以及复合物的光化学特性。设计并合成了新型二茂铁修饰的人工核碱基受体。人工受体与二核苷酸紧密结合，其中受体的氢键基序与二核苷酸的两个核碱基以明确的方式相互作用。此外，人工受体将天然二核苷酸溶解到低极性溶剂中。由于二茂铁是一种氧化还原活性分子，一种新型具有电化学响应的人工受体的构建正在取得进展。

This research project is to construct artificial supramolecular systems capable of being responsive to external stimuli such as chemical and physical ones. Summary of the results obtained in this project is as follows:1. Artificial saccharide receptors were designed and synthesized. The receptors selectively recognized ribose, deoxyribose, and glucose, respectively, and employed the recognition strategy of substrate-induced organization of the conformation (induced-fit mechanism). The receptors solubilized the native saccharides into less-polar solvents such as CHCl_3. Selective transformation of saccharides by use of the receptors is now under way.2. We developed a new class of water-soluble cyclophanes, pyrenophanes, capable of recognizing nucleobases by hydrophobic interaction. The pyrenophanes showed only excimer-emission, and the emission was quenched upon recognition of nucleobases. We are now investigating the interactions between the pyrenophanes with DNA and the photochemical characteristics of the complexes.3. Novel ferrocene-modified artificial nucleobase receptors were designed and synthesized. The artificial receptors strongly bound to dinucleotides, in which the hydrogen-bonding motif of the receptors interacts with two nucleobase residues of the dinucleotides in a well-defined manner. Furthermore, the artificial receptors solubilized the native dinucleotides into less-polar solvents. As ferrocene is a redox-active molecule, the construction of a new type of artificial receptors possessing an electrochemical response is now progress.