Expanding the supramolecular chemistry of carbon nanohoops

在化学系大分子、超分子和纳米化学（MSN）项目的支持下，俄勒冈州大学的Ramesh Jasti教授正在开发通用方法，将纳米环分子作为构建模块，自组装成具有可控形状和功能的精确纳米材料。 设想了两种形式的结构：互锁结构和环中环结构。 要探索新的合成方法来实现这些目标。 预期所需的产物具有独特的尺寸依赖性光电性质和形状持久的孔。 目标产品在从气体吸附、过滤和质量传输到分子电子学、开关和传感的广泛领域中具有潜在用途。参与该项目的学生将在跨学科的环境中接受培训，并获得有机合成，超分子化学和纳米科学的经验。 与俄勒冈州夏季科学计划的大学合作，为在俄勒冈州服务不足的学生群体提供实践科学经验。 将分子结构单元组装成具有新颖功能的纳米材料是材料科学、超分子化学和合成等领域的重大挑战。 虽然在过去十年中已经开发了用于制备纳米环的合成方法，但是这些纳米环自组装成具有受控形状和功能的纳米级材料相对未被探索。 在该项目的第一个目标中，Jasti小组将探索氮掺杂的纳米环类似物和金属配位策略，以制备链烷结构，这将代表分子机器的简单版本。 Jasti小组将探索这些新的链烷结构的新特性，例如通过纳米尺度上的机械键或超低摩擦运动进行光电通信。在该项目的第二个目标中，Jasti研究小组计划利用疏水效应来驱动环中环纳米环复合物的形成。 这些结构是双壁碳纳米管的分子类似物，并且由于组件的超分子组装，预计具有独特的光电特性和动力学。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program of the Division of Chemistry, Professor Ramesh Jasti at the University of Oregon is developing general methods to use nanohoop molecules as building blocks to self-assemble into precise nanoscale materials with controlled shape and function. Two forms of structures are envisioned: interlocked structures and ring-in-ring structures. Novel synthetic approaches are to be explored to achieve these objectives. The desired products are expected to have unique size-dependent optoelectronic properties and shape persistent pores. The products being targeted are of potential use in broad ranging fields from gas adsorption, filtration and mass transport to molecular electronics, switching, and sensing. Students involved in the project will be trained in an interdisciplinary environment and acquire experience in organic synthesis, supramolecular chemistry, and nanoscience. A partnership with the University of Oregon Summer Science Program provides hands-on science experience to groups of students who have been underserved in the state of Oregon. The assembly of molecular building blocks into precise nanoscale materials with novel function is a grand challenge at the nexus of materials science, supramolecular chemistry, and synthesis. While synthetic approaches for the preparation of nanohoops have been developed in the last decade, the self-assembly of these nanohoops into nanoscale materials with controlled shape and function is relatively unexplored. In the first aim of the project, the Jasti group will explore nitrogen-doped nanohoop analogues and metal-coordination strategies to prepare catenane structures, which would represent simple versions of molecular machines. The Jasti group will probe these new catenane structures for novel properties such as optoelectronic communication through the mechanical bond or ultra-low friction motion on the nanoscale. In the second aim of this project, the Jasti research team plans to use the hydrophobic effect to drive the formation of ring-in-ring nanohoop complexes. These structures are molecular analogues to double-walled carbon nanotubes and are predicted to have unique optoelectronic properties and dynamics due to the supramolecular assembly of the components.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.