Developing electron transfer from chiral circularly polarized luminescence-based photocatalysts towards selective radical cross-coupling reactions

开发从手性圆偏振发光光催化剂到选择性自由基交叉偶联反应的电子转移

• 批准号: 10449749
• 负责人: Gael Ung
• 金额: $ 20.13万
• 依托单位: UNIVERSITY OF CONNECTICUT STORRS
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10449749
• 关键词: Cerium; Chemistry; Complex; Coupled; Coupling; Development; Electron Transport; Electrons; Engineering; Exciton; Exhibits; Fluorescence; Funding; Generations; Goals; Harvest; Laboratories; Lanthanoid Series Elements; Lead; Left; Ligands; Light; Methodology; Methods; Pathway interactions; Photosensitizing Agents; Population; Property; Publishing; Reaction; Reagent; Research; Research Project Grants; Side; Source; Technology; Transition Elements; Vertebral column; absorption; base; design; emission spectroscopy; light emission; luminescence; manufacturing process; next generation; programs; virtual

Summary The long-term goal of the proposed project is to develop the next generation of cross-coupling reactions. We aim at eliminating the need of differentiation between coupling partners, while retaining high reactivity and selectivity by utilizing polarized radical species. We will take advantage from the fact that a polarized radical species will only react with another radical species with the opposite polarization. The central hypothesis is that complexes emitting strong circularly polarized luminescence (CPL) possess a high population of high energy polarized excitons that can be harvested for reactivity. CPL is the emission of light with preferential circular polarization and has emerged as the next generation light source. Lanthanide complexes are the best CPL emitters, and cerium complexes are known to be photosensitizers capable of generating radical species. We will synthesize luminescent enantiopure chiral complexes exhibiting CPL, and will examine their ability to transfer polarized electrons. To attain strong CPL and photosensitizing ability, we will target chiral rigid guanidinate ligands. We will also examine the ability of these complexes to transfer polarized electrons and generate polarized radicals with quenching studies of the complexes in their photoexcited states. We will also evaluate the reactivity of polarized radicals toward Csp3-Csp3 cross-coupling reactions using a combination of fluorescence studies and flow chemistry. During the proposed funding period, we expect the delivery of the first examples of CPL-active cerium complex, as well as proof-of-principle for polarized electron transfer. We will also develop early stage proof-of-concept for the polarized radical-based cross-coupling reactions.

概括 该项目的长期目标是开发下一代交叉偶联反应。我们 旨在消除偶联伙伴之间的差异化需求，同时保持高反应性和 利用极化自由基物种的选择性。我们将利用这样一个事实：两极分化的激进分子 物种只会与具有相反极化的另一种自由基物种发生反应。中心假设是 发射强圆偏振光（CPL）的配合物拥有大量高能量 可以收集用于反应的极化激子。 CPL是优先圆形光的发射 偏振并已成为下一代光源。稀土配合物是最好的 CPL 已知发射体和铈络合物是能够产生自由基物质的光敏剂。我们将 合成具有 CPL 的发光对映体纯手性配合物，并将检查它们的转移能力 极化电子。为了获得强大的CPL和光敏能力，我们将瞄准手性刚性胍酸酯 配体。我们还将检查这些复合物转移极化电子并产生的能力 极化自由基及其光激发态配合物的猝灭研究。我们也会评估 极化自由基对 Csp3-Csp3 交叉偶联反应的反应性，使用以下组合 荧光研究和流动化学。在拟议的资助期内，我们预计将交付第一批 CPL 活性铈配合物的示例，以及极化电子转移的原理证明。我们还将 开发基于极化自由基的交叉偶联反应的早期概念验证。