Heteroditopic Calixarene Based Receptors for Ion Pair Recognition and Mechanical Bond Assembly

该项目旨在构建新型环状和互锁的“宿主”分子，这些分子被设计为在单个分子宿主框架内同时结合带正电荷和负电荷的客体物种。这样的多识别位点受体系统具有令人兴奋的多种潜在用途，如新的提取和膜转运剂，以及在传感，开关和类似分子机器的行为。使用“桶形”杯[4]芳烃分子作为分子支架该项目首先将各种阳离子和阴离子结合基序共价连接到该分子框架上，异位受体广泛的无机离子对配位研究将阐明合作结合效应，其中络合阳离子将增强阴离子的结合，反之亦然。适当设计的分子阳离子-阴离子螺纹组件，与无机离子对和中性配体螺纹一起将与这些双位主体系统形成互穿组装体。基于这些伪轮烷组装研究，目标互锁链状索烃分子结构将使用离子对模板合成方法和它们的离子对结合特性和化学或电化学诱导的可切换旋转分子运动进行研究。这些互锁的索链烷体系的表面组装将导致新的界面，其化学特性可以通过可切换的化学和/或电化学控制来调节，其中旋转分子运动暴露表面限制的索链烷体系的亲水性带电基团和疏水性中性基团。将尝试在分子尺度的空间分辨率下驱动（写入）这种开关，并随后通过近端探针方法读取诱导的变化。

This project aims to construct novel cyclic and interlocked 'host' molecules that are designed to simultaneously bind positively and negatively charged guest species within a single molecular host framework. Such multiple recognition site receptor systems have an exciting variety of potential uses as new extraction and membrane transport agents as well as having nanotechnological applications in sensing, switching and molecular machine-like behaviour.Using the 'bucket shaped' calix[4]arene molecule as a molecular scaffold the project begins with the covalent attachment of various cation and anion binding motifs onto this molecular framework to produce new cyclic heteroditopic receptors. Extensive inorganic ion-pair coordination studies will elucidate cooperative binding effects where a complexed cation will enhance the binding of an anion and vice-versa. Appropriately designed molecular cation-anion threading components, together with inorganic ion-pairs and neutral ligand threads will form interpenetrative assemblies with these ditopic host systems. Building on these pseudo-rotaxane assembly investigations, target interlocked chain-like catenane molecular structures will be synthesised using ion-pair templation synthetic methodologies and their ion-pair binding properties and chemically or electrochemically induced switchable rotational molecular movement investigated. The surface assembly of these interlocked catenane systems will lead to novel interfaces whose chemical characteristics may be modulated by switchable chemical and/or electrochemical control where rotational molecular movement exposes hydrophilic charged and hydrophobic neutral groups of the surface confined catenane systems. An attempt will be made to drive ( write ) this switching at molecular scales of spatial resolution and to subsequently read induced changes by proximal probe methods.