Transition Metal Clusters as Single-Molecule Magnets

在这个由化学系化学结构、动力学和机制B计划资助的项目中，佛罗里达大学化学系的乔治·克里斯托教授正在寻找新的分子化合物，这些分子化合物可以用作纳米级磁性材料，具有与量子计算机和自旋电子学等新的世纪技术相关的特性。分子化学为这一目标带来了溶解度和结晶度等优势。 它还提供了优化特定研究分子的方法，例如表征对这些潜在应用重要的量子物理特性。该项目的范围广泛，涵盖化学和物理。 该项目还提供了纳米尺度的新知识，这是传统磁性纳米颗粒通常无法获得的。研究的多学科性质还为学生，包括代表性不足的少数群体提供了广泛的高水平教育和培训。此外，还开展了一些外联，教育和国际活动，包括国家和国际会议组织以及针对K-12学生的当地社区的年度化学日。这项研究包括两个主要目标。第一个是合成由二肟或二羧酸桥连接的两个或多个单分子磁体（SMM）的共价连接聚集体，并研究其磁性和量子物理性质。SMM之间的弱相互作用导致量子叠加/纠缠态。 这些模糊和脆弱的影响，检测和研究的技术，如高频电子顺磁（HFEPR）光谱在固态。将HFEPR研究扩展到冷冻溶液对于确定结构和量子效应在溶解时是否保持不变至关重要，为他们的研究提供了第二阶段。第二个目的是制备具有Mnx/O（x = 8-12）笼状结构的分子，所述笼状结构包含不同类型的杂金属M'（M' = Ca、La、Ln、Bi、Pb等）。在他们的中心。目标是在分子化合物中模拟具有钙钛矿结构的某些混合金属氧化物的重复单元，特别是多铁性的BiMnO 3和LnMnO 3（Ln =镧系元素），从而制备用作“分子多铁性”的分子，表现出SMM和可切换的电极化。

In this project funded by the Chemical Structure, Dynamics and Mechanisms B Program of the Chemistry Division, Professor George Christou of the Department of Chemistry at the University of Florida is seeking new molecular compounds that can function as nanoscale magnetic materials with properties relevant to new 21st century technologies such as quantum computers and spintronics. Molecular chemistry brings advantages such as solubility and crystallinity to this goal. It also provides methods for optimizing molecules for particular studies, such as characterizing the quantum physics properties important to these potential applications. The project's scope is broad spanning chemistry and physics. The project also provides new knowledge at the nanoscale that is not often available from traditional magnetic nanoparticles. The multi-disciplinary nature of the research also provides broad, high-level education and training for students, including underrepresented minorities. In addition, a number of outreach, education and international activities are carried out, including state and international conference organization and an annual Chemistry Day in the local community targeted at K-12 students. This research consists of two main objectives. The first one is to synthesize covalently-linked aggregates of two or more single-molecule magnets (SMMs) linked by dioximate or dicarboxylate bridges and to study their magnetic and quantum physics properties. Weak interactions between the SMMs leads to quantum superposition/entanglement states. These nebulous and fragile effects are detected and studied with techniques such as high-frequency electron paramagnetic (HFEPR) spectroscopy in the solid state. Extension of the HFEPR studies to frozen solutions is crucial to determine if structures and quantum effects remain unchanged on dissolution, providing a second phase for their study. The second objective is the preparation of molecules with a Mnx/O (x = 8-12) cage-like structures containing a heterometal M' of a different type (M' = Ca, La, Ln, Bi, Pb, etc.) at their center. The goal is to mimic in molecular compounds the repeating unit of certain mixed-metal oxides with the perovskite structure, particularly BiMnO3 and LnMnO3 (Ln = lanthanide) that are multiferroics, and thus to prepare molecules that function as 'molecular multiferroics', exhibiting both SMM and switchable electric polarization.