RUI: Large Kinetic Isotope Effects as Mechanistic Indicators in Organometallic Chemistry

RUI：大动力学同位素效应作为有机金属化学的机械指标

• 批准号: 2247038
• 负责人: Miriam Bowring
• 金额: $ 30万
• 依托单位: Reed College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247038&HistoricalAwards=false
• 关键词: RUI; Large; Kinetic; Isotope; Effects

With support from the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Miriam A. Bowring of the Department of Chemistry at Reed College is working with undergraduate researchers to study the fundamental mechanisms of chemical reactions with potential applications to greener alternative fuels. One main tool for finding out how reactions work is the study of reaction rates. It has been observed that some reactions involving hydrogen are much faster than expected compared to the corresponding reactions with deuterium. The researchers aim to determine the mechanisms that cause such unusual observation, which could lead to improved understanding of chemical reactivity. Furthermore, the group is collaborating with high school chemistry teachers on research in reclaiming palladium in road dirt as a catalyst, which may attract broader student interests in STEM (science, technology, engineering and mathematics). Anomalously large kinetic isotope effects (KIEs) are occasionally observed during mechanistic investigations of promising organometallic catalysts. The mechanistic origins of large KIEs are not well understood, and are often ascribed to proton tunneling. The proposed research encompasses mechanistic study of two systems with large observed KIEs: protonolysis to release methane from platinum methyl complexes, and formic acid dehydrogenation with an iridium-ruthenium bimetallic catalyst. To determine the origins of the large KIEs in these systems, kinetic studies will be performed while systematically adjusting variables such as reaction concentration, stoichiometry, and temperature, properties of the organometallic fragments, and the acid.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.

在化学系化学结构、动力学机制B项目的支持下，Miriam A.里德学院化学系的鲍林正在与本科生研究人员合作，研究化学反应的基本机制，并可能应用于更绿色的替代燃料。研究反应速率是了解反应如何进行的一个主要工具。 已经观察到，与氘的相应反应相比，涉及氢的一些反应比预期快得多。研究人员的目标是确定导致这种不寻常观察的机制，这可能会导致对化学反应性的更好理解。此外，该小组正在与高中化学教师合作研究回收道路污垢中的钯作为催化剂，这可能会吸引更广泛的学生对STEM（科学，技术，工程和数学）的兴趣。在有机金属催化剂的机理研究中，偶尔会发现异常大的动力学同位素效应。 大KIE的机制起源还没有得到很好的理解，通常归因于质子隧穿。拟议的研究包括两个系统的机制研究与大观察到的KIEs：质子分解释放甲烷铂甲基络合物，和甲酸脱氢与铱-钌催化剂。 为了确定这些系统中的大KIE的来源，将进行动力学研究，同时系统地调整变量，如反应浓度，化学计量，和温度，有机金属碎片的性质，和酸。这个奖项反映了NSF的法定使命，并已被认为是值得支持的评估使用基金会的智力价值和更广泛的影响审查标准。