Supramolecular Chemistry with Macromolecules

9706909 Gibson A roxatane由物理上缠绕在线性分子上的环状分子组成，在环状和线状物种之间没有共价键；环状分子由互锁的环状分子组成。超分子化学的概念将被用来合成新的聚合物杂环烷和环戊烷。微量热法将提供与两个组分的性质(大小、刚性、结构)、溶剂和温度等因素有关的线性物种对环状分子进行线性化的基本数据。在这个小分子热力学数据库的基础上，这些积木将被用于生产新的聚合物材料。三个具有高缔合常数的典型超分子体系将被用来构建全新的聚轮烷，包括主链和接枝体系。一类新的超支化和树枝状大分子的结构完整性基于轮烷重复单元，将从具有AB2官能团的拟轮烷(没有塞子)合成；重复单元将由具有大环末端基团的线性物种组成，线性部分贯穿另一个单元的大环。另一类新的大分子，滑链聚合物，由线性结构中的轮烷重复单元组成，将通过标准BB单体与新型伪轮烷、AA拓扑单体聚合制备，其中一个官能团位于线性客体部分，一个官能团位于环状或主体部分，线状部分带有较大的封闭基；由于轮烷结构的顺应性，此类材料有望在纵向拉伸和压缩下表现出新颖的行为。由于络合过程可以在适当的条件下逆转，因此性质(光吸收、粘度、固态结构、溶解度、机械性能等)这些体系中的大多数预计会对环境敏感，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，最古老的轮烷和顺丁烯形成方法，即所谓的化学转化法，将首次应用于制备聚轮烷和聚顺丁烯。这种方法涉及具有线性成分的分子的反应，这些线性成分通过分子内的大环通过“临时键”连接。通过线状丝线上的末端官能团进行聚合将在临时键被破坏后产生多轮烷。另一方面，通过自穿线体系的环化反应，合成了一系列AA、AB和AB2型的功能化的2-戊二烯，它们将聚合成各种新的线型、超支化和树枝状聚-2-戊二烯。超分子化学原理将被应用于构建几个新的聚合物材料家族，这些聚合物材料包含机械连接而不是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有望对其环境和外部刺激做出异常的响应。因此，这些系统为控制物理化学性质提供了全新的设计原则，可以使新的传感器、智能或适应性材料和电子设备成为可能。***

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. ***