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

在这个由化学结构、动力学和机理B计划和刺激竞争研究的既定计划（EPSCoR）计划资助的项目中，南卡罗来纳大学化学和生物化学系的谢丽尔·l·威斯库尔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去除产物/催化剂等。在反应结束时限制需要的净化量，因为净化可能是昂贵和浪费的。问题是，与在溶液中进行反应相比，使用这些聚合物的反应往往会降低产率或选择性。本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。本项目结合有机化学、高分子化学和超分子化学来解决这一问题，并将为研究生和本科生提供多样化的训练场地。更广泛的影响还包括为女科学家提供指导，以帮助留住女性从事科学工作。由于发展基于聚合物的化学是可持续化学的一个有价值的目标，成功地将方法转移到聚合物是一项重要的努力。因此，重要的是要了解为什么化学转移到可溶性聚合物往往遭受损失的选择性和/或产率。我们假设聚合物微环境的极性与散装溶剂不同，而散装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。提出的研究包括将溶剂化发色团纳入功能化聚合物中，以了解官能团如何影响微环境极性。此外，异硫脲催化剂将加入到这些相同的功能化聚合物中，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基于聚合物介质的合成的最佳条件，而不是基于散装溶剂的合成，因此，可能在可持续化学领域具有长期的科学影响。该奖项反映了美国国家科学基金会的法定使命，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。

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.