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

这一奖项授予加州大学伯克利分校的Jeffrey R.Long教授，该奖项授予大分子、超分子和纳米化学项目，涉及作为单分子磁体的许多络合物的合成和详细表征。该项目包括以下研究：(A)以高各向异性Re为基础的结构单元为特征的新型氰桥联配位簇合物和链化合物的合成和表征，重点是确定哪些因素导致高磁各向异性势垒；(B)将已知的具有自旋交叉行为的铁(II)配合物引入此类化合物，可能导致第一批可光开关的单分子和单链磁体的例子；(C)合成高对称性的多核咪唑桥联簇合物，其中钒(II/III)或铁(II/III)的混合价态通过双交换机制导致能量很好地隔离的高自旋基态；(D)具有严格的轴对称的镧系元素和榄系元素配合物的合成，这可以提供一种产生大弛豫势垒的手段；(E)对所选的三角锥体铁(II)配合物的配位场以及零场分裂参数的操纵。总而言之，龙博士和他的团队将开发合成新的单分子磁体的一般策略，预计将揭示高密度信息存储和基于自旋的分子电子潜在感兴趣的新型磁性行为。这项研究的更广泛影响包括合成技术遗产，创造具有潜在技术重要性的新材料，以及对博士后、研究生和本科生进行无机材料合成和表征方面的教育和培训。作为一项相关的教育活动，龙博士将继续领导加州大学伯克利分校化学系创建材料化学专业的努力。

This award in the Macromolecular, Supramolecular & Nanochemistry Program to Professor Jeffrey R. Long of the University of California, Berkeley, involves the synthesis and detailed characterization of a number of complexes as single-molecule magnets. The project consists of the following studies: (a) synthesis and characterization of new cyano-bridged coordination clusters and chain compounds featuring high-anisotropy rhenium-based building units, with emphasis on establishing what factors contribute to high magnetic anisotropy barriers; (b) incorporation of iron(II) complexes known to exhibit spin crossover behavior into such compounds, possibly leading to the first examples of photoswitchable single-molecule and single-chain magnets; (c) synthesis of high-symmetry, multinuclear imidazolate-bridged clusters in which vanadium(II/III) or iron(II/III) mixed valence leads to an energetically well-isolated high-spin ground state via a double exchange mechanism; (d) synthesis of lanthanide and actinide complexes with rigorous axial symmetry, which could provide a means of generating a large relaxation barrier; (e) manipulation of the ligand field, and consequently the zero-field splitting parameters, of selected trigonal pyramidal iron(II) complexes. In sum, Dr. Long and his group will develop general strategies for the synthesis of new single-molecule magnets that are expected to reveal new types of magnetic behavior of potential interest for high-density information storage and spin-based molecular electronics.The broader impacts of this research include a legacy of synthetic techniques, the creation of new materials of potential technological importance, and the education and training of postdoctoral, graduate, and undergraduate students in the synthesis and characterization of inorganic materials. As a related educational activity, Dr. Long will continue to lead an effort to create a materials chemistry major within the Department of Chemistry at UC Berkeley.