Synthesis, Characterization, and Reactivity Studies of Cerium-Ligand Multiple Bonds and Organometallics and Comparisons with Thorium, Uranium, and Group IV Congeners

铈-配体多重键和有机金属的合成、表征和反应性研究以及与钍、铀和 IV 族同系物的比较

• 批准号: 2247668
• 负责人: Eric Schelter
• 金额: $ 55万
• 依托单位: University of Pennsylvania
• 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: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247668&HistoricalAwards=false
• 关键词: Synthesis; Characterization; Reactivity; Studies; Cerium

With support from the Chemical Synthesis program in the Chemistry Division, Professor Eric Schelter and his research group at the University of Pennsylvania are investigating the organometallic chemistry of cerium, thorium, uranium, and Group IV metal compounds, especially complexes of those elements that include metal-ligand multiple bonds. Cerium is a rare-earth metal, but it exhibits properties similar both to other rare-earth metals and to the transition and actinide metals that surround it in the periodic table. This project aims at comparing the behavior of cerium with these surrounding metals in order to determine the factors that determine the unique properties of cerium. A better understanding of cerium chemistry is expected to contribute to the design new applications for cerium in catalytic, materials and chemical biology applications. The results of these studies will also likely contribute to a greater understanding of rare earth metals that are critical for renewable energy and defense applications. The project will provide student training in the handling and manipulation of the rare earths and contribute to the maintenance of a trained work force in this important area. Hands-on research projects for high school students are also envisioned to provide early exposure to science.The overall goal of this project is to synthesize new metal-ligand multiply bonded organometallic compounds of cerium, uranium, thorium, and Group IV metals. The spectroscopic properties and reactivity patterns across these metals will be compared. The central hypothesis is that the properties of isostructural, tetravalent metal complexes will inform on bonding differences and 4f-/5d-covalency across this broad spectrum of elements. Organometallic complexes and metal-ligand multiple bonds of cerium, uranium, thorium, and group IV elements will be synthesized. Their spectroscopic properties will be studied by multi-nuclear NMR and X-ray absorption spectroscopy. Computational methods will be applied to model the spectroscopic properties and to understand the relative covalent contributions to bonding. Isostructural complexes that undergo equilibrium reactions will also be used to observe dynamic differences in bonding across the elements of cerium, thorium and uranium, and extending to the group IV elements. The fundamental knowledge developed from the work is expected to contribute new and unique examples of organometallic compounds and associated spectroscopic information that will broaden understanding of chemical bonding. Rare earth element-containing materials are used in the energy and defense industries and there are currently no substitutes. Advancing cerium/rare earth chemistry will contribute to improving beneficiation and separation of rare earths, and in so doing, contribute to national security.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.

在化学划分的化学合成计划的支持下，宾夕法尼亚大学的埃里克·谢尔特（Eric Sc​​helter）教授及其研究小组正在研究葡萄，Thorium，Thorium，Thorium，Uranium和IV群金属化合物的有机金属化学，尤其是包括金属多种键的元素的复合物。铜是一种稀土金属，但它具有类似于其他稀土金属的性能，以及在周期表中围绕它的过渡和acttinide金属。该项目的目的是将葡萄的行为与这些周围金属的行为进行比较，以确定确定墨西哥属性独特特性的因素。预计对铜质化学的更好理解将为催化，材料和化学生物学应用中的新应用做出贡献。这些研究的结果也可能有助于对可再生能源和防御应用至关重要的稀土金属有更多的了解。该项目将在处理和操纵稀土方面提供学生培训，并为在这一重要领域维持受过训练的劳动力做出贡献。还设想为高中生的动手研究项目提供早期接触科学。该项目的总体目的是合成新的金属配体多粘结粘合的有机金属化合物，硫磺，铀，th和IV类金属。将比较这些金属的光谱特性和反应性模式。中心假设是，在这一广泛的元素范围内，等值元，四含量金属配合物的特性将告知粘结差异和4F-/5D合作。将合成有机金属配合物和金属配体的多个元素键，铀，th和IV元素的多个键。它们的光谱特性将通过多核NMR和X射线吸收光谱进行研究。计算方法将应用于对光谱特性进行建模，并了解对键合的相对共价贡献。经历平衡反应的同生成复合物也将用于观察存在的葡萄，th和铀和铀元素的键合中的动态差异，并扩展到IV组元素。预计从工作中发展的基本知识将为有机金属化合物和相关光谱信息提供新的独特示例，从而扩大对化学键合的理解。能源和防御工业中使用了稀土元素的材料，目前没有替代品。推进葡萄污水/稀土化学将有助于改善稀土稀有地球的利益和分离，并为国家安全做出贡献。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点评估来支持的，并具有更广泛的影响。