CAREER:CAS: Mechanistic Investigation of Photoredox Reactions

在这个由化学部化学结构，动力学机制-B计划资助的CAREER项目中，宾厄姆顿大学（SUNY）化学系的John Swierk正在研究光氧化还原反应的动力学和机制。这些反应利用光来产生新的和难以接近的化学键，这些化学键与药物和其他小分子的合成有关。这项研究的目标是为成功但知之甚少的光氧化还原反应提供坚实的机理基础。该项目的结果有可能导致更快的反应速率和产品收率，并能够开发新的反应。这项工作在于有机，物理和无机化学的接口，并将支持各级科学家的跨学科培训。社区学院的学生将作为受训人员纳入研究计划，作为更广泛的外联活动的一部分，重点是促进STEM（科学，技术，工程和数学）学生从两年制大学成功过渡到四年制大学。光氧化还原反应依赖于短寿命自由基中间体的产生和控制。虽然是成功的，但光氧化还原反应的基本反应步骤和动力学特征很差。拟议的工作旨在确定通过不同途径控制选择性的分子水平上的关键动力学描述符（例如，持久自由基效应、自由基链机制）。然后，这些分子水平的见解将与有关反应结果的信息（如产物产率和量子效率）联系起来。此外，拟议的工作还试图了解如何使用离子介质来调整非生产性电子转移途径的速率。深共熔溶剂（DES）中的光氧化还原反应的研究代表了这两个领域的新方向，从这些研究中收集的信息可以允许开发功能，合理设计的溶剂，可以提高产品的选择性和反应速率。DES中电子和氢原子转移的基础研究是重要的，其目标是支持新的光氧化还原方法的发展。更广泛地说，对长寿命自由基稳定性、氢原子转移催化剂、自由基链机制和电子转移的研究有可能将这项拟议工作的影响扩大到光氧化还原催化之外。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。

In this CAREER project, funded by the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, John Swierk of the Department of Chemistry at Binghamton University (SUNY) is investigating the kinetics and mechanisms of photoredox reactions. These reactions utilize light to generate new and difficult-to-access chemical bonds that are relevant in the synthesis of pharmaceuticals and other small molecules. The goal of this research is to provide a solid mechanistic foundation for photoredox reactions that are successful but poorly understood. Results from this project have the potential to lead to faster reaction rates and product yields, as well as enable the development of new reactions. This work lies at the interface of organic, physical, and inorganic chemistry and will support the interdisciplinary training of scientists at all levels. Community college students will be integrated into the research program as trainees as part of broader outreach activities focused on facilitating successful transitions of STEM (science, technology, engineering and mathematics) students from two-year to four-year universities. Photoredox reactions rely on the generation and control of short-lived radical intermediates. While successful, the underlying reaction steps and kinetics of photoredox reactions are poorly characterized. The proposed work seeks to identify the key kinetic descriptors at a molecular level that control selectivity via different pathways (e.g., persistent radical effect, radical chain mechanism). These molecular level insights are then to be connected with information about reaction outcomes, such as product yield and quantum efficiency. In addition, the proposed work also seeks to understand how ionic media can be used to tune the rate of unproductive electron transfer pathways. Studies of photoredox reactions in deep eutectic solvents (DES) represent a new direction for both fields and the information gleaned from these studies may allow for the development of functional, rationally designed solvents that can enhance product selectivity and reaction rates. Fundamental investigations into electron and hydrogen atom transfer in DES are important with the goal of supporting the development of new photoredox methods. More broadly, investigations into the stability of long-lived radicals, H-atom transfer catalysts, radical chain mechanisms, and electron transfer have the potential to expand the impact of this proposed work beyond photoredox catalysis.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.