CAREER: Design Strategies for High-Performance Bismuth- and Lanthanide-Based Single-Molecule Magnets

职业：高性能铋基和镧系单分子磁体的设计策略

• 批准号: 2339595
• 负责人: Selvan Demir
• 金额: $ 77万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2029-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2339595&HistoricalAwards=false
• 关键词: CAREER; Design; Strategies; Performance; Bismuth

With support from the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, Selvan Demir of the Department of Chemistry at Michigan State University is employing organometallic chemistry to develop new classes of molecular compounds with interesting magnetic properties, known as single-molecule magnets (SMMs). The exciting potential applications of SMMs span from high-density information storage, quantum computing, to spin-based electronic devices, but hinge on increasing the spin-reversal barrier, magnetic blocking temperature, and coercive field - all metrics that describe the molecule’s ability to retain information after removing an applied external magnetic field. This project will develop new rational design strategies to engender new types of SMMs comprising bismuth and the paramagnetic lanthanides. The combination of the electronic features of bismuth and lanthanide sites could usher in a new generation of SMMs with unparalleled performance characteristics. The project tightly integrates academic research and education in several ways to provide the highest level of education to the public and students at all stages. This includes a creative approach “Science Meets Art” that utilizes the power of visualization to facilitate entry into the elaborate spin-based science subject where exhibitions in a gallery and museums are planned. The development of an experimental quantum information science course accompanied with a magnetism kit is also encompassed alongside lectures at local schools.Single molecule magnets (SMMs) exhibit a barrier to spin reversal and in the absence of quantum tunneling, magnetic hysteresis similar to bulk magnets. Therefore, one of the most important but also challenging goals is to increase simultaneously spin ground state and magnetic anisotropy, critical goals in the pursuit of strongly coupled multinuclear SMMs. Strong coupling is required as it suppresses fast relaxation pathways such as quantum tunneling which is needed for high-temperature SMMs. In addition, new chemical space must be explored to advance the field. Accordingly, this project aims to develop new rational design strategies to engender (i) the first bismuth-centered SMMs, (ii) new lanthanide SMMs containing bismuth radicals, (iii) new redox-active heterocyclic ligands composed of bismuth and nitrogen donors, (iv) the first multinuclear SMMs consisting of bismuth-nitrogen heterocyclic bridges, and (v) the first multinuclear SMMs containing bismuth-nitrogen heterocyclic radicals. From a fundamental point of view, the thorough study of magnetic coupling pathways through diamagnetic and paramagnetic bridges has the potential to advance knowledge of relaxation dynamics occurring in SMMs, and in so doing, pave the way for future SMM design.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，密歇根州立大学化学系的Selvan Demir正在利用有机金属化学开发具有有趣磁性的新型分子化合物，称为单分子磁体（SMM）。SMM令人兴奋的潜在应用范围从高密度信息存储，量子计算到基于自旋的电子设备，但取决于增加自旋反转势垒，磁阻挡温度和矫顽场-所有指标都描述了分子在去除外加磁场后保留信息的能力。本计画将开发新的合理设计策略，以产生包含铋及顺磁镧系元素的新型SMM。铋和镧系元素位点的电子特征的组合可以带来具有无与伦比的性能特征的新一代SMM。该项目以多种方式将学术研究和教育紧密结合起来，为公众和各个阶段的学生提供最高水平的教育。这包括一种创造性的方法“科学遇见艺术”，利用可视化的力量，以促进进入精心制作的自旋为基础的科学主题，其中在画廊和博物馆的展览计划。除了在当地学校举办讲座外，还开发了一个实验性量子信息科学课程，并配备了一套磁性材料。单分子磁体（SMM）表现出自旋反转的势垒，在没有量子隧穿的情况下，磁滞与块状磁体相似。因此，最重要但也是最具挑战性的目标之一是同时增加自旋基态和磁各向异性，这是追求强耦合多核SMM的关键目标。需要强耦合，因为它抑制了快速弛豫路径，例如高温SMM所需的量子隧穿。此外，必须探索新的化学空间以推进该领域。因此，本项目旨在开发新的合理设计策略，以产生（i）第一个铋中心的SMM，（ii）新的含铋自由基的镧系SMM，（iii）由铋和氮供体组成的新的氧化还原活性杂环配体，（iv）第一个由铋-氮杂环桥组成的多核SMM，以及（v）第一个含铋-氮杂环自由基的多核SMM。从基本的角度来看，通过反磁和顺磁桥的磁耦合路径的深入研究有可能推进在SMM中发生的弛豫动力学知识，并在这样做，为未来的SMM设计铺平了道路。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。