CAS: Understanding Microenvironment Polarity in Polymers and the Effect it has on Reaction Rates and Selectivity

在这个由化学结构、动力学机制B计划和刺激竞争研究的既定计划（EPSCoR）计划资助的项目中，南卡罗来纳州大学化学和生物化学系的Wiskur正在开发可用于有机反应的聚合物，以发展更可持续的化学。 化学家在有机反应中使用聚合物来帮助在反应完成时去除产物/催化剂/等，以限制所需的纯化量，因为纯化可能是昂贵和浪费的。 问题在于，与仅在溶液中进行时相比，使用这些聚合物的反应倾向于遭受降低的产率或选择性。 这项研究的目的是了解聚合物的微环境如何影响这些反应，并调整微环境，以便在使用这些聚合物时保持产率和选择性。该项目结合有机化学，高分子化学和超分子化学来解决这个问题，并将为研究生和本科生提供多样化的培训基地。 更广泛的影响还包括指导女科学家，以帮助留住科学界的女性。由于发展基于聚合物的化学是实现可持续化学的一个有价值的目标，因此成功地将方法转移到聚合物是一项重要的奋进。 因此，重要的是理解为什么转移到可溶性聚合物上的化学物质倾向于遭受选择性和/或产率的损失。 我们假设聚合物微环境的极性不同于本体溶剂，本体溶剂不能提供最佳结果所需的最佳环境。 该提案着眼于聚合物的微环境极性如何影响反应结果，如产率和选择性。 建议的研究包括将一个solvatochromophore功能化的聚合物，以了解官能团如何影响微环境的极性。 此外，将异硫杂环丁烷催化剂掺入这些相同的官能化聚合物中，并用于催化模型反应，以了解微环境对速率和选择性的影响。 如果成功，这些研究有可能阐明聚合物介质合成的最佳条件，而不是本体溶剂合成，因此，可能在可持续化学领域具有长期的科学影响力。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

In this project, funded by the Chemical Structure, Dynamics & Mechanisms B Program and the Established Program to Stimulate Competitive Research (EPSCoR) program, Sheryl L. Wiskur of the Department of Chemistry and Biochemistry at the University of South Carolina is developing polymers that can be used in organic reactions for the development of more sustainable chemistry. Chemists employ polymers in organic reactions to aid in the removal of products/catalysts/etc. at reaction completion to limit the amount of purification that is needed, since purification can be costly and wasteful. The problem is that reactions employing these polymers tend to suffer from diminished yield or selectivity versus when they were just run in solution. The goal of this research is to understand how the microenvironment of the polymer affects these reactions and tune that microenvironment such that yield and selectivity are retained when employing these polymers. This project incorporates organic chemistry, polymer chemistry, and supramolecular chemistry to solve this problem, and will provide a diverse training ground for graduate students and undergraduate students alike. Broader impacts also include the mentoring of women scientists to aid in retaining women in science.Since developing polymer-based chemistry is a valuable goal towards sustainable chemistry, the successful transfer of methodology to polymers is an important endeavor. Therefore, it is important to understand why chemistry transferred onto soluble polymers tend to suffer loss in selectivity and/or yield. We hypothesize that the polarity of the polymer’s microenvironment is different than the bulk solvent, which does not provide the optimal environment needed for the best results. This proposal looks at how the microenvironment polarity of the polymer can affect reaction outcomes such as yield and selectivity. Studies proposed include incorporating a solvatochromophore into functionalized polymers to understand how the functional groups affect the microenvironment polarity. Additionally, an isothiourea catalyst will be incorporated into these same functionalized polymers and used to catalyze a model reaction to understand the microenvironment effect on rate and selectivity. If successful, these studies have the potential to illuminate the optimal conditions for polymer media-based synthesis as opposed to bulk solvent-based synthesis and, as such, could have long term scientific reach in the area of sustainable chemistry.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.