Synthesis of Doubly-Threaded Interlocked Macromolecules

凯斯西储大学的Stuart Rowan教授开发了新的聚合物结构的合成方法，并研究了这些结构如何影响聚合物的性能。这项研究在设计和制备具有理想独特性能的新型聚合物材料方面具有潜在的社会效益。该项目涉及研究生和本科生、当地一所女子高中的高中生，以及来自内城克利夫兰市立学区（通过使节项目）代表性不足群体的学生。这项研究的综合方法为各级学生提供了一个令人兴奋的学习环境和广泛的研究经验。此外，Rowan教授和他的研究小组为“自然材料”外展项目设计了新的演示，这是克利夫兰博物馆在马丁·路德·金博士纪念日“冬季发现日”的一部分。该项目旨在(i)让当地社区了解聚合物，以及大自然的材料如何帮助我们创造一个可持续发展的星球，（ii）培训当前的研究生如何就科学技术与公众和年轻学生进行沟通和教育。该研究项目由化学部的大分子、超分子和纳米化学项目支持，涵盖合成和金属配位化学、计算建模以及聚合物科学和表征。它侧重于设计、合成和表征具有双线结构的聚合物，其中两条链穿过一个大环。新的合成方法利用金属配位作为聚合步骤的热力学驱动力，并利用动态共价化学（以合环复分解的形式）作为共价固定步骤来获得聚[n]链烷，或利用高产硫烯化学来获得双螺纹聚[3]轮烷和滑环凝胶。聚合物具有膨胀/收缩的能力，而不会显著改变键合或扭转角度，因此预计它们将表现出不同寻常的粘弹性特性。

Prof. Stuart Rowan of Case Western Reserve University develops synthetic methods that allow access to new polymer architectures and studies how these architectures impact polymer properties. This research has potential societal benefit with regards to design and preparation of novel polymeric materials with desirable unique properties. The project involves graduate and undergraduate students, high school students from a local girl's high school, and students of under-represented groups from the inner city Cleveland Municipal School District (through the Envoys program). The integrated approach of this research provides students at all levels with an exciting learning environment and broad research experiences. In addition, Prof. Rowan and his research group design new demonstrations for the outreach program entitled "Natures Materials", which is part of the Cleveland Museum's "Winter Discovery Day" on Dr. Martin Luther King Jr. Day. This program aims (i) to expose the local community to polymers and how Nature's materials can help us create a sustainable planet, and (ii) to train current graduate students on how to communicate and educate the general public and younger students about science and technology.This research project, which is supported by the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division, encompasses synthetic and metal-coordination chemistry, computational modeling, as well as polymer science and characterization. It focuses on the design, synthesis and characterization of polymers with doubly-threaded architectures where two chains are threaded through one macrocycle. The new synthetic methodology utilizes metal-ligand coordination as the thermodynamic driving force for the polymerization step and either dynamic covalent chemistry (in the form of ring closing metathesis) as the covalent fixing step to access the poly[n]catenanes or high yielding thiol-ene chemistry to access the doubly threaded poly[3]rotaxanes and slide ring gels. The polymers will have the ability to expand/contract without significantly altering bond or torsion angles and as such it is predicted they will exhibit unusual viscoelastic properties.