A Coordination Chemistry Approach to the Synthesis of Single-Molecule Magnets

在化学系化学结构、动力学和机理B(CSDM-B)计划的支持下，加州大学伯克利分校化学系的Jeffrey R.Long教授正在设计和合成新的单分子磁体。在去除外加磁场后，这些物种显示出磁记忆的特征，长期以来，人们一直认为这一特性完全源于块状永磁体材料中的长程磁序。然而，在单个纳米分子中观察到这种行为是值得注意的，并可能导致高密度数据处理、量子信息科学和量子传感等领域的变革性进展。该项目位于合成分子化学和物理学的交界处，因此非常适合具有广泛兴趣的跨学科年轻科学家，并促进纳入来自代表性不足背景的学生。最后，一个推广计划将寻求教育湾区K-12的学生关于磁性分子在社会中的作用和奇迹。这项研究将利用基本的分子设计原理来新合成单分子磁体，目标是工作温度较高的系统。该项目将检验中心假设，即配位化学可以合成具有定制电子结构的分子，从而产生具有前所未有的工作温度的单分子磁体。更具体地说，这一建议侧重于设计和合成具有(I)最大轴向晶场各向异性以提供高弛豫势垒和(Ii)强磁交换相互作用以缓解有害量子隧穿的新型稀土和过渡金属基分子。这个项目将扩展我们关于如何操纵分子中广泛的磁性性质的知识，包括单离子磁各向异性、磁矫正力和磁耦合相互作用。该项目所产生的基础知识可能会导致众多技术领域的进步，包括量子信息科学、超硬磁学和生物医学成像。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Structure, Dynamics & Mechanisms B (CSDM-B) Program of the Chemistry Division, Professor Jeffrey R. Long of the Department of Chemistry at the University of California, Berkeley, is designing and synthesizing new single-molecule magnets. Upon removal of an applied magnetic field, these species display signatures of magnetic memory, a property long thought to arise exclusively from long-range magnetic order in bulk permanent magnet materials. However, the observation of such behavior in individual nanoscopic molecules is remarkable and may lead to transformative advances in areas such as high-density data processing, quantum information science, and quantum sensing. This project lies at the interface of synthetic molecular chemistry and physics and is therefore ideally suited for interdisciplinary young scientists with broad interests and for promoting the inclusion of students from underrepresented backgrounds. Finally, an outreach program will seek to educate Bay Area K–12 students on the role and wonder of magnetic molecules in society.This research will employ fundamental molecular design principles to newly synthesize single-molecule magnets, aiming for systems with high operating temperatures. The project will test the central hypothesis that coordination chemistry can enable the synthesis of molecules with tailored electronic structures, thereby giving rise to single-molecule magnets with unprecedented operating temperatures. More specifically, this proposal focuses on the design and synthesis of new lanthanide- and transition metal-based molecules with (i) maximal axial crystal-field anisotropy to give high relaxation barriers and (ii) strong magnetic exchange interactions to mitigate deleterious quantum tunneling. This project will expand our knowledge of how to manipulate a wide range of magnetic properties in molecules, including single-ion magnetic anisotropy, magnetic coercivity, and magnetic coupling interactions. The fundamental knowledge generated from this project may lead to advances in myriad technological areas–including quantum information science, ultra-hard magnetism, and biomedical imaging.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.