Supramolecular Chemistry with Macromolecules

roxatane由一个环分子物理地连接到一个线性分子上，在环和线性分子之间没有共价键；连环烷由互锁的环状分子组成。超分子化学的概念将被用于合成新的聚合物环烷和链烷。微量热法将提供关于线性物种的环分子穿线的基本数据，这些因素包括两种成分的性质（大小、刚性、结构）、溶剂和温度。在这个小分子热力学数据库的基础上，这些构建模块将用于生产新的聚合物材料。本文将利用具有高结合常数的三种典型超分子体系构建全新的聚轮烷，包括主链体系和接枝体系。一类结构完整性基于轮烷重复单元的新型超支化树突状大分子将由具有AB2官能团的拟环烷（无止环）合成；重复单元将由具有大环端基的线性物种组成，线性部分穿过另一个单元的大环。另一类新的大分子，由线性结构的轮烷重复单元组成的滑动连接聚合物，将通过标准BB单体与新型伪轮烷聚合而成，其中一个功能位于线性客体部分，一个位于环或主部分，线性部分具有较大的阻塞基团；由于轮烷结构的顺应性，这种材料有望在纵向拉伸和压缩下表现出新的行为。由于络合过程可以在适当的条件下逆转，因此这些体系的性质（光吸收、粘度、固态结构、溶解度、机械性质等）预计对其环境敏感，例如温度、溶剂、氧化还原条件、金属离子的存在或不存在或介质的酸度。最后，最古老的轮烷和连环烷生成方法，即所谓的化学转化法，将首次应用于制备聚轮烷和聚连环烷。这种方法涉及到具有线性成分的分子通过“临时键”连接的大环在分子内螺纹的反应。在暂时键断裂后，通过线状螺纹上的末端官能团聚合将产生聚轮烷。另一方面，将自螺纹体系进行环化，得到一系列功能化的AA型、AB型和AB2型2链烷，这些2链烷将被聚合形成各种新型的线性、超支化和枝状聚2链烷。超分子化学原理将应用于若干新型高分子材料家族的构建，这些材料家族包含机械而非化学连接在一起的单元。由于其新颖的拓扑结构，这些新材料的物理性质被期望对其环境和外部刺激具有不同寻常的响应。因此，这些系统为控制物理和化学特性提供了全新的设计原则，可以实现新的传感器，智能或适应性材料和电子设备。＊＊＊

9706909 Gibson A roxatane consists of a cyclic molecule physically threaded onto a linear molecule with no covalent bonds between the cyclic and the linear species; a catenane consists of interlocked cyclic molecules. The concepts of supramolecular chemistry will be employed to synthesize new polymeric roxatanes and catenanes. Microcalorimetry will provide fundamental data on the threading of cyclic molecules by linear species with respect to factors such as the nature of the two components (size, rigidity, structure), the solvent and temperature. Building on this thermodynamic data base for small molecules, these building blocks will be used to produce new polymeric materials. Three prototypical supramolecular systems that possess high association constants will be utilized to construct entirely new polyrotaxanes, including main chain and graft systems. A new class of hyperbranched and dendritic macromolecules whose structural integrity is based on rotaxane repeat units will be synthesized from psuedorotaxanes (without stoppers) having AB2 functionalities; the repeat units will consist of a linear species with macrocyclic end groups, the linear portion being threaded through the macrocycle of another unit. Another new class of macromolecules, slip link polymers, consisting of a rotaxane repeat unit in a linear structure will be prepared by polymerization of standard BB monomers with novel pseudorotaxane, AA topological monomers in which one functionality resides on the linear guest portion and one on the cyclic or host portion and the linear portion bears a bulky blocking group; such materials are expected to show novel behavior under longitudinal tension and compression because of the compliance of the rotaxane structure. Since the complexation processes can reversed under suitable conditions the properties (light absorption, viscosity, solid state structure, solubility, mechanical properties, etc.) of these systems are expected to be sensitive the thei r environments, e.g., temperature, solvent, redox conditions, the presence or absence of metal ions or the acidity of the medium. Finally the oldest method of rotaxane and catenane formation, the so-called chemical conversion method, will be applied for the first time to prepare polyrotaxanes and polycatenanes. This method involves reaction of molecules that possess linear components threaded intramolecularly through a macrocycle attached via a "temporary bond". Polymerization via terminal functionalities on the linear thread will yield polyrotaxanes after the temporary bond is broken. On the other hand, cyclization of the self threaded system will be employed to make a series of functionalized 2 catenanes of the AA, AB, and AB2 types, which will be polymerized to form a variety of new linear, hyperbranched and dendritic poly 2 catenanes. %%% The principles of supramolecular chemistry will be applied to the construction of several new families of polymeric materials which contain units that are mechanically rather than chemically linked together. Because of their novel topological structures the physical properties of these new materials are expected to be unusually responsive to their environments and external stimuli. Thus these systems offer entirely new design principles for controlling physical and chemical properties that could enable new sensors, smart or adaptable materials and electronic devices. ***