Synthesis of Catenane-based Polymers and Materials Using Orthogonal Metal Templation

在化学系大分子、超分子和纳米化学项目的支持下，华盛顿大学圣路易斯分校（WUSTL）的Jonathan巴恩斯将研究和扩展有效的合成方法，以制备一系列基于链烷的聚合物和网络材料。链烯是一种机械互锁分子，由于其独特的分子键和结构而引起了人们的研究兴趣。例如，机械互锁分子（MIM）具有明确定义的拓扑结构和独特的分子结构，并且可以在分子水平上提供传统聚合物根本无法达到的构象和平移自由度。该项目将导致新型聚[n]索烃和索烃基材料的开发，从而为拓扑控制聚合物和材料领域的未来研究和开发奠定基础。为了让年轻学生参与STEM（科学、技术、工程和数学），巴恩斯将与圣路易斯国际象棋俱乐部（SLCC）合作，开发将国际象棋和科学的重叠原则（例如，分析思维、计划、焦点等）。WUSTL青年科学家项目（YSP）的学生将获得实习指导。该项目旨在通过实施金属模板聚合合成来弥合小分子和聚[n]索烃之间的合成差距，同时通过开发可与传统单体配对的官能化索烃单体和交联剂来解决潜在的可扩展性问题。该研究旨在消除合成更高分子量的低聚和聚[n]索烃中的一些限制。 目前的方法在每次迭代后显示出降低的产率，和/或因为一锅法通常导致产生不需要的动力学副产物的非生产性交叉反应。从拟议的研究中获得的基本合成和物理聚合物知识预计将有助于开发下一代基于MIM的材料和应用。 这些聚合物和材料的表征将允许将关键指标制成表格，例如热转变温度（Tg + Tm）、缠结的分子量阈值（Mc，Me）和材料性质，包括剪切模量和杨氏模量，以及韧性、拉伸强度，本文提出的研究的高潮将是开发新种类的聚[n]索烃和基于索烃的材料，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 the support of the Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry, Jonathan Barnes of Washington University-St. Louis (WUSTL) will investigate and expand on efficient synthetic methods to prepare a series of catenane-based polymers and networked materials. Catenanes are mechanically interlocked molecules (MIMs) that have drawn research interest due to their unusual molecular linkages and structures. Mechanically interlocked molecules (MIMs), for example, possess well-defined topologies and unique molecular architectures and can offer conformational and translational degrees of freedom at the molecular level that are simply not accessible with traditional polymers. The project will result in the development of new classes of poly[n]catenanes and catenane-based materials, thus laying the foundation for future research and development in the area of topologically controlled polymers and materials. To engage young students in STEM (science, technology, engineering and mathematics), Barnes will build on a collaboration with the St. Louis Chess Club (SLCC) to develop outreach that would merge the overlapping principles of chess and science (e.g., analytical thinking, planning, focus, etc.). Students from the The Young Scientist Program (YSP) at WUSTL will be mentored with internships.The project seeks to bridge the synthetic gap between small-molecule and poly[n]catenanes by implementing metal-templated, convergent syntheses, while also addressing potential scalability issues through the development of functionalized catenane monomers and crosslinkers that can be paired with traditional monomers. The research aims to remove some of the limitations seen in synthesizing higher molecular weight oligo- and poly[n]catenanes. Current approaches show decreased yields after each iteration, and/or because one-pot approaches often lead to unproductive cross reactions that generate unwanted kinetic byproducts. The fundamental synthetic and physical polymer knowledge gained from the proposed research is expected to aid the development of next-generation MIM-based materials and applications. Characterization of these polymers and materials will allow key metrics to be tabulated, such as thermal transition temperatures (Tg + Tm), molecular weight thresholds for entanglement (Mc, Me), and material properties including shear and Young’s moduli, in addition to toughness, tensile strength, etc. The culmination of the research proposed herein would be the development of new classes of poly[n]catenanes and catenane-based materials, an achievement that would help build a foundation for future research and development in the area of topologically controlled polymers and polymeric materials.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.