Expanding Reductive Chemistry and Oxidation State Diversity Using the Synthetic Chemistry of the Rare-Earth Metals

利用稀土金属的合成化学扩大还原化学和氧化态多样性

• 批准号: 2154255
• 负责人: William Evans
• 金额: $ 52.5万
• 依托单位: University of California-Irvine
• 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: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2154255&HistoricalAwards=false
• 关键词: Expanding; Reductive; Chemistry; Oxidation; State

With the support of the Chemical Synthesis (SYN) Program of the Chemistry Division, Professor William J. Evans, Chemistry Department, University of California – Irvine is studying the chemistry of seven new oxidation states of rare earth elements. Rare earths are heavy metals that have vital roles in electronics, medicine, and others. The rare earth metals most commonly have an oxidation state of +3, but some can have other values such as +2. This project explores the chemistry of seven rare earth elements for which a +2 oxidation state has recently been discovered. Elements with this new oxidation state have properties which make them ideal for applications in energy conservation through magnetism (neodymium in the world’s most powerful magnets) and lighting (europium and terbium in energy efficient lighting) as well as in medicine (gadolinium in magnetic resonance imaging), and catalysis (cerium in automotive catalytic converters). The Evans group is studying how these new oxidation states can impact fundamental chemistry, while training students in the science of these strategically important metals. Professor Evans is also pursuing applications in the development of the smallest, most efficient, magnets that can be designed at a molecular level, namely single-molecule magnets, and in quantum information science to make new types of quantum bits, i.e. qubits. The project provides training and education in the manipulation and application development of the rare earth elements and contains an outreach component that encourages middle and high school students to continue in science.The chemistry of new +2 ions of praseodymium, gadolinium, terbium, holmium, erbium, and lutetium is being explored to evaluate the special reactivity and physical properties that can arise from their unexpected electron configurations which involve not only the valence 4f orbitals but also the higher energy 5d orbitals. These 4fn5d1 ions differ from traditional +2 oxidation states of the lanthanide metals that have 4fn+1 electron configurations. The chemistry of the new +2 rare earth ion of yttrium, a 4d1 system, is also being studied for comparison. The synthesis of new molecular complexes of these ions has led to a rapidly evolving perspective of how these new ions can be utilized. For example, a molecular complex of Lu2+ has been found to have one of the largest electron-nucleus hyperfine coupling constants that provides a stable transition called a clock transition that could be used as a qubit with minimum noise. The project also will seek to discover new small molecule activation reactions, e.g. with nitrogen and nitrogen oxides, and other new oxidation states, e.g. the +1 ions of the rare earth metals. In addition to training students to develop technical expertise of f-block chemistry there is significant outreach to middle and high school students and participation in a University of California - Irvine Chemistry Undergraduate Scholars Program to support first generation, low income and minority students in General Chemistry through peer mentoring.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) 项目的支持下，加州大学欧文分校化学系的 William J. Evans 教授正在研究稀土元素的七种新氧化态的化学，稀土元素是重金属。在电子、医学等领域发挥着重要作用。稀土金属最常见的氧化态为+3，但有些也可能具有其他值，例如+2。该项目探讨了七种稀土元素的化学性质。最近发现了+2氧化态。具有这种新氧化态的元素具有使其成为磁性节能应用（世界上最强大的磁铁中的钕）和照明（节能照明中的铕和铽）的理想选择。 ）以及医学（磁共振成像中的钆）和催化（汽车催化转换器中的铈）埃文斯小组正在研究这些新的氧化态如何发挥作用。埃文斯教授不仅对基础化学产生影响，同时还对学生进行这些具有重要战略意义的金属科学方面的培训，并致力于开发可在分子水平上设计的最小、最高效的磁体（即单分子磁体）以及其他领域的应用。量子信息科学，制造新型量子比特，即量子比特，该项目提供稀土元素操纵和应用开发方面的培训和教育，并包含鼓励中学生继续学习科学的外展部分。新的+2离子镨、钆、铽、钬、铒和镥正在被探索，以评估它们意想不到的电子构型所产生的特殊反应性和物理性质，这些电子构型不仅涉及价态 4f 轨道，还涉及这些 4fn5d1 离子的更高能量 5d 轨道。与具有 4fn+1 电子构型的镧系金属的传统 +2 氧化态不同。钇的新+2稀土离子（4d1系统）也正在研究中进行比较。这些离子的新分子复合物的合成导致了如何利用这些新离子的快速发展的观点。 Lu2+分子复合物被发现具有最大的电子-核超精细耦合常数之一，可提供称为时钟跃迁的稳定跃迁，可用作噪声最小的量子位。该项目还将寻求发现新的量子位。小分子活化反应，例如氮和氮氧化物以及其他新的氧化态，例如稀土金属的+1离子高中生并参与加州大学欧文分校化学本科学者计划，通过同伴指导支持普通化学领域的第一代、低收入和少数族裔学生。该奖项反映了 NSF 的法定使命，并已通过使用基金会的智力优点和更广泛的影响审查标准进行评估，认为值得支持。

项目成果

Tetramethylcyclopentadienyl Samarium(II) Metallocene Chemistry: Isolation of a Bimetallic Sm(II)/Sm(II) Complex

四甲基环戊二烯基钐(II) 茂金属化学：双金属 Sm(II)/Sm(II) 络合物的分离

• DOI: 10.3390/inorganics11010004
• 发表时间: 2023
• 期刊: Inorganics
• 影响因子: 2.9
• 作者: Nguyen, Joseph Q.;Ziller, Joseph W.;Evans, William J.
• 通讯作者: Evans, William J.

Accessing Lanthanide Metallocene Two-Electron Reduction Chemistry Using 2,2′-Bipyridine

使用 2,2-联吡啶获取镧系金属茂双电子还原化学

• DOI: 10.1021/acs.organomet.3c00074
• 发表时间: 2023
• 期刊: Organometallics
• 影响因子: 2.8
• 作者: Stennett, Cary R.;Nguyen, Joseph Q.;Ziller, Joseph W.;Evans, William J.
• 通讯作者: Evans, William J.

Reduction of Rare-Earth Metal Complexes Induced by γ Irradiation

γ 辐照引起的稀土金属配合物的还原

• DOI: 10.1021/acs.inorgchem.2c02857
• 发表时间: 2022
• 期刊: Inorganic Chemistry
• 影响因子: 4.6
• 作者: Moore, William N.;White, Jessica R.;Wedal, Justin C.;Furche, Filipp;Evans, William J.
• 通讯作者: Evans, William J.

van der Waals Heterostructures Based on Nanolayered Paramagnetic Tm(II) Compounds and Boron Nitride for Investigating Spin Frustration

基于纳米层顺磁 Tm(II) 化合物和氮化硼的范德华异质结构用于研究自旋挫败

• DOI: 10.1021/acsanm.3c00662
• 发表时间: 2023
• 期刊: ACS Applied Nano Materials
• 影响因子: 5.9
• 作者: Moore, William N.;McSorley, Timothy J.;Vincent, Alexandre;Ziller, Joseph W.;Jauregui, Luis A.;Evans, William J.
• 通讯作者: Evans, William J.

Room-Temperature Stable Ln(II) Complexes Supported by 2,6-Diadamantyl Aryloxide Ligands

• DOI: 10.1021/acs.inorgchem.2c02167
• 发表时间: 2023-01-03
• 期刊: INORGANIC CHEMISTRY
• 影响因子: 4.6
• 作者: Anderson-Sanchez, Lauren M.;Yu, Jason M.;Evans, William J.
• 通讯作者: Evans, William J.