Development of molecular manipulation technique based on host-guest interactions

我们的目标是发展一种基于主客体相互作用的分子操作技术。这项研究是不及物动词型技术的开创性工作，该技术利用有机分子通过弱化学键自动组装的能力。主要研究结果如下：1.我们以甾体分子，特别是胆汁酸及其衍生物作为有机宿主。自上个世纪以来，这些分子已为人们所熟知，但除了脱氧胆酸和阿朴胆酸外，它们形成包合晶体的能力尚不清楚。发现大多数甾体化合物与多种有机物形成包合物。不同情况下的包含行为不同。这表明，包结现象在有机物质中是普遍存在的，因为甾体的异构体数量超过十亿。发现表面两亲分子通过氢键结合形成双层组装体。组件的比较研究澄清了两亲层以各种方式堆叠在一起。这表明不对称的中分子量分子导致了一定的多样性。3.我们证实了多个氢键基团之间的可控结合可能是有机分子操纵技术中最重要的一步。四个或三个离散的氢键基团以各种方式结合在一起。这种多样性是负责变量包含现象，这是依赖于主机结构。4.我们构建了一个系统，适合于研究的各个方面的主客体相互作用，通过使用个人计算机。该系统使我们能够建立和检索的数据库的甾体包合化合物。

We aimed to develop a molecular manipulation technique on the basis of host-guest interactions. This research constitutes a pioneering work for an intransitive-verb-type technique, which utilizes an ability of organic molecules to assemble through weak chemical bonding automatically. The results are summarized as follows ;1.We employed steroidal molecules, particularly bile acids and their derivatives, as organic hosts. These molecules have been well-known since last century, but their abilities to form inclusion crystals are not known except deoxycholic acid and apocholic acid. We found that most of the steroids form the inclusion compounds with a variety of organic substances. The inclusion behaviors varies from one case to another. This indicates that inclusion phenomena are general in organic substances, because isomers of the steroids amount to over one billion.2.We determined over fifty crystal structures of the inclusion compounds. It was found that facially amphiphilic molecules associate through hydrogen bonding to give bilayred assemblies. Comparative studies of the assemblies clarified that the amphiphilic layrs stack together in various ways. This indicates that asymmetric middle-molecular-weight molecules cause some diversity.3.We confirmed that the controlled combination among multiple hydrogen-bonding groups may serve as the most important step for the manipulation technique of organic molecules. Four or three discrete hydrogen bonding groups associate together in various ways. This diversity is responsible for variable inclusion phenomena which is dependent on the host structures.4.We constructed a system suitable for studying on various aspects of the host-guest interactions by using personal computers. The system enabled us to construct and search a data base of the steroidal inclusion compounds.