Hyperpolarization Catalysts for in situ Mechanistic Studies

在化学部化学合成计划的资助下，伊利诺伊大学香槟分校化学系的Alison Fout将开发新的钴基化合物，这些化合物可以促进重要化学过程中的氢反应。氢气是一种非常重要的化学原料，用于各种化学过程。然而，它本身不会反应或反应非常缓慢。为了解决这个问题，已经开发了许多金属化合物，这些化合物可以激活氢并大大加快其反应速率。这些化合物被称为催化剂，几乎都是基于昂贵的稀有金属。该项目研究了一种较便宜的金属钴激活氢的能力。由于氢如何添加到各种化合物中的细节很难确定，因此在这项研究中将使用一种称为仲氢的不寻常形式的氢，以将测量的灵敏度提高到20万倍。此外，该项目旨在提高下一代科学家的多样性，公平性和包容性。Fout教授和她的学生将参加3 M暑期学者计划，该计划旨在为来自代表性不足的群体的本科生提供研究经验，下一代伊利诺伊科学家，该计划吸引农村学校的小学生，以及针对6- 8年级女孩的Bonding Camp for Girls。该项目合成了可用作仲氢诱导极化（PHIP）催化剂的钴络合物。这需要在整个催化循环中保持S=0的抗磁性复合物，用于直接和间接超极化。为了实现这一点并获得Co（I）/Co（III）催化循环，制备含有富电子部分的配体和卡宾的络合物。它们催化PHIP的活性在包括烯烃、炔和芳烃在内的一系列底物上进行评估，这些底物在其官能团中具有长弛豫核。一些底物是聚合催化中的关键反应物。在这些情况下，PHIP效应用于检测和研究以前没有观察到的机械中间体。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。

With funding from the Chemical Synthesis Program in the Chemistry Division, Alison Fout in the Department of Chemistry at the University of Illinois Urbana-Champaign, will develop new cobalt-based compounds that can facilitate the reactions of hydrogen in important chemical processes. Hydrogen is an extremely important chemical feedstock that is used a wide variety of chemical processes. However, by itself it does not react or reacts very slowly. To circumvent this problem a number of metal compounds have been developed that activate hydrogen and greatly speed its rate of reactions. These compounds are called catalysts and almost all are based on expensive, rare metals. This project studies the ability of a less expensive metal, cobalt, to activate hydrogen. As the details of how hydrogen adds to various compounds is difficult to determine, an unusual form of hydrogen known as parahydrogen will be used in this study to increase the sensitivity of measurements up to 200,000 times. In addition, the project aims to improve diversity, equity, and inclusion in the next generation of scientists. Prof. Fout and her students will participate in the 3M Summer Scholars Program, which aims to provide research experiences to undergraduate students from underrepresented groups, the Next Generation Illinois Scientist, which engages elementary students in rural schools, and the Bonding Camp for Girls, which targets 6-8th grade girls.This project synthesizes cobalt complexes that may serve as parahydrogen-induced polarization (PHIP) catalysts. This requires diamagnetic complexes that remain S=0 throughout the catalytic cycle for both direct and indirect hyperpolarization. To achieve this and to access a Co(I)/Co(III) catalytic cycle, complexes of ligands containing electron-rich moieties and carbenes are prepared. Their activity to catalyze PHIP is evaluated across a range of substrates including olefins, alkynes, and arenes, which feature long-relaxing nuclei in their functional groups. Some of the substrates are key reactants in polymerization catalysis. In these cases, the PHIP effect is used to detect and study of mechanistic intermediates that have not previously been observed.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.