Functional Organic Nanotubes from Self-Assembled Bis-Urea Macrocycles

美国国家科学基金会的大分子、超分子和纳米化学项目支持南卡罗来纳州大学的琳达·清水教授的工作，以制造定义明确的微小一维通道（纳米管）来回答基本的科学问题。 这些纳米管是由简单的甜甜圈状分子制备的，这些分子相互堆叠，形成微小的稻草状结构。 纳米管可以装载气体和小分子，而不会改变通道结构。 所获得的先进知识有助于更好地理解分子传输，并有助于优化工业气体分离的性能，以及开发环境友好的方法来进行工业氧化反应。 该奖项的教育部分包括三个方面：（1）培养研究生的研究能力，为他们未来在科学或工程领域的职业生涯做好准备;（2）支持本科生和高中生的第一次研究经验;和（3）它广泛地促进了科学的兴趣，使化学家进入南卡罗来纳州的K-12间教室，展示科学方法，培养对化学和自然科学的兴趣，特别是在少数民族高入学率的中学和高中。自下而上的方法，通过分子自组装设计功能材料提供了一个有效的和高保真的战略，准备好-定义的纳米结构，可以用来回答基本问题。 在这个研究项目中，Shimizu小组通过控制简单大环构建块的自组装来制备结构可调的一维纳米通道。 这些纳米通道用于三个主要目的：（1）研究作为通道尺寸、客体尺寸以及客体和通道壁之间可能发生的相互作用的函数的气体或客体分子通过通道的传输速率。 (2)组织能与光相互作用的分子，并研究这种组织对其性质的影响，以及（3）产生氧的反应形式，单线态氧，并控制有机底物的氧化。

The Macromolecular, Supramolecular and Nanochemistry Program of the National Science Foundation supports the work of Professor Linda Shimizu of the University of South Carolina to make well-defined, tiny 1-dimensional channels (nanotubes) to answer fundamental scientific questions. These nanotubes are prepared from simple, donut-shaped molecules that stack one on top of each other to make tiny straw-like structures. The nanotubes can be loaded with gases and small molecules without altering the channel structure. The advanced knowledge acquired leads to a greater understanding of molecular transport and could help optimize performance for industrial gas separations and the development of environmentally friendly methods to carry out industrial oxidation reactions. The educational component of this award encompasses three areas: (1) it trains graduate students in research and prepares them for future careers in science or engineering fields; (2) it supports the first research experiences of undergraduates and high school students; and (3) it broadly promotes interest in science by bringing chemists into South Carolina's K-12 classrooms to showcase the scientific method and to foster interest in chemistry and in the natural sciences, especially at high minority enrollment middle schools and high schools.Bottom-up approaches to design functional materials through molecular self-assembly provide an efficient and high fidelity strategy to prepare well-defined nanostructures that can be used to answer fundamental questions. In this research project, the Shimizu group prepares structurally tunable 1-dimensional nanochannels by controlling the self-assembly of simple macrocyclic building blocks. These nanochannels are used for three main purposes: (1) to study the rates of transporting gas or guest molecules through the channels as a function of the channel dimensions, guest dimensions, and the interactions that can occur between the guests and the channel walls. (2) to organize molecules that can interact with light and to study the effect of this organization on their properties, and (3) to generate a reactive form of oxygen, singlet oxygen, and to control the oxidation of organic substrates.