Platform-Supported Pairs of Lewis Acidic Metal Cations to Control and Catalyze Dinitrogen Functionalization

平台支持的路易斯酸性金属阳离子对控制和催化二氮官能化

• 批准号: 2154369
• 负责人: Polly Arnold
• 金额: $ 25.42万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 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://www.nsf.gov/awardsearch/showAward?AWD_ID=2154369&HistoricalAwards=false
• 关键词: Platform; Supported; Pairs; Lewis; Acidic

With the support of the Chemical Synthesis (SYN) Program of the Chemistry Division, Professor Polly Arnold of the University of California–Berkeley, is studying the structure, bonding, and reactivity of f-block molecules with the long-term, ambitious goal of converting atmospheric nitrogen to ammonia and amines. Nitrogen gas (N2) is the major component of the atmosphere and potentially an inexpensive, chemically benign starting material for the industrial preparation of a vast variety of important chemical products. Currently, it is the feedstock for a single commercialized reaction, the Haber-Bosch process, which converts nitrogen to ammonia. This process is used on an enormous scale and provides the major source of nitrogen fertilizer worldwide. However, it functions at high temperatures and pressures, both consuming much energy and generating roughly 1% of global annual carbon dioxide emissions. Consequently, the discovery of more efficient processes to convert nitrogen to useful projects is extremely important. This project seeks to develop rare earth compounds that will mediate the conversion of nitrogen into ammonia and related compounds at low temperatures and pressures without generating carbon dioxide. The fundamental research proposed herein is expected to make fundamental contributions to important, unanswered questions about the chemical bonding in compounds composed of some of the heaviest atoms in the periodic table. It will also train members of the future workforce in the chemistry of the technology-critical rare earth elements, and in sustainable catalysis, both of which are high priority science areas for the nation.Under this award, the Arnold team will develop bimetallic rare earth and related Lewis acidic metal complexes supported by rigid tetraphenolate ligands with important and challenging goal of arriving at entries into the first catalytic conversion of dinitrogen N2 to secondary silylamines by a non-radioactive complex. The proposed program will work with specific lanthanides and co-reductants, according to their size, redox potentials, and Lewis acidity, to define the role of d- and f-orbitals in the stabilization of reduced intermediates and to enable the synthesis of new functionalized amines. Because electrons can be stored and transported through the ligand framework, the proposed program is also designed to tease apart metal/ligand contributions and develop new, lower-energy ways to deliver the reducing equivalents to the N2. The project will train students is the handling and manipulation of sensitive rare earth compounds and in the development of these into reagents for the reduction of small molecules.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.

在化学系化学合成（SYN）计划的支持下，加州大学伯克利分校的Polly Arnold教授正在研究f-区分子的结构，键合和反应性，其长期雄心勃勃的目标是将大气中的氮转化为氨和胺。氮气（N2）是大气的主要成分，并且可能是用于工业制备各种重要化学产品的廉价、化学上良性的起始材料。目前，它是单一商业化反应的原料，即哈伯-博世工艺，该工艺将氮气转化为氨。这一过程被大规模使用，并提供了全世界氮肥的主要来源。然而，它在高温和高压下运行，既消耗大量能源，又产生约1%的全球年二氧化碳排放量。因此，发现更有效的方法将氮转化为有用的项目是非常重要的。该项目旨在开发稀土化合物，在低温和低压下将氮转化为氨和相关化合物，而不会产生二氧化碳。本文提出的基础研究预计将对由周期表中一些最重原子组成的化合物中的化学键的重要而未回答的问题做出根本性的贡献。它还将在技术关键的稀土元素化学和可持续催化方面培训未来的劳动力，这两个领域都是国家高度优先的科学领域。阿诺德研究小组将开发由刚性四酚盐配体支撑的稀土和相关的刘易斯酸性金属络合物，其重要而具有挑战性的目标是进入第一个催化转化的领域。通过非放射性络合物将二氮N2转化为仲甲硅烷基胺。拟议的计划将与特定的镧系元素和共还原剂，根据其大小，氧化还原电位，和刘易斯酸度，以确定的d-和f-轨道的作用，在稳定的还原中间体，并使新的官能化胺的合成。由于电子可以通过配体框架存储和传输，因此该计划还旨在分离金属/配体的贡献，并开发新的低能量方法来将还原当量传递给N2。该项目将培养学生处理和操作敏感的稀土化合物，并将其开发成还原小分子的试剂。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。