Gated Molecular Baskets

分子识别和封装在指导化学转化过程中的好处可能是巨大的。设计能够执行同步操作的功能化主机是我们的目标。我们寻求构建信息丰富的分子，并进行结构功能研究，以了解在人工环境中调节化学反应的复杂方法。特别是，我们建议开发和研究能够折叠和包埋客体化合物的篮状分子的工作机制。还将研究它们内部的化学反应作为组装动力学、构象和立体化学的函数。折叠过程是通过附加在篮缘上的杂环‘瓣’的分子内相互作用来调节的。对客人的监禁取决于它与篮板或篮子内部的相互作用。通过这种方式，客体交换受到篮子构象特征的限制，这反过来将允许探索在受限空间中发生的分子运输和化学转化之间的关系。对外界刺激的快速打开和关闭或构象调整也是许多酶调节底物、产物或溶质进出其活性部位的机制；因此，在生物世界中实现了活性的变构调节。拟议的研究是基础性的。它旨在了解在非自然环境中分子组装、反应性和识别之间的基本方面和关系。潜在的影响是广泛的，而不是具体的：该提案旨在发展可能影响未来技术的科学，并改进有用化学品的加工。它的使命包含在教育研究生和本科生关于物理有机化学的现代问题。该项目也可以被描述为多学科的，学生通过咨询不同的化学学科来解决科学挑战。

The benefit of molecular recognition and encapsulation in directing the course of chemical transformations can be enormous. Designing functionalized hosts capable to perform synchronized operations is our objective. We seek to build information-rich molecules and conduct structure-function studies to learn about sophisticated ways for regulating chemical reactivity in artificial settings. In particular, we propose to develop and study the working mechanisms of basket-like molecules capable to fold and incarcerate a guest compound. The investigation of chemical reactions in their interior as a function of the assembly dynamics, conformation and stereochemistry will also be conducted. The folding process is mediated by intramolecular interactions of the heterocyclic 'flaps' appended to the basket rim. The incarceration of a guest is dictated by its interaction with the flaps or the basket interior. In this way the guest exchange is restricted by the baskets' conformational characteristics, which in turn will allow exploring the relationship between the molecular trafficking and chemical transformations occurring in the confined space. Rapid opening and closing of a flap-like gate or conformational adjustments in response to an external stimulus are also mechanisms by which many enzymes regulate trafficking of substrates, products or solutes in and out of their active sites; the allosteric regulation of activity is thus achieved in the biological world. The proposed research is fundamental. It is directed toward understanding the basic aspects and relationships between molecular assembly, reactivity and recognition in unnatural environments. The potential impact is rather broad then specific: the proposal is aimed to develop science that can potentially influence future technologies and improve the processing of useful chemicals. Its mission is contained in educating graduate and undergraduate students about modern problems in physical organic chemistry. The program can also be portrayed as multidisciplinary whereby students resolve scientific challenges by consulting different chemistry disciplines.