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

这个大分子、超分子和纳米化学项目的奖项授予了加州大学伯克利分校的Jeffrey R. Long教授，该奖项涉及到一些作为单分子磁铁的复合物的合成和详细表征。本项目包括以下研究：(a)具有高各向异性铼基结构单元的新型氰基配位团簇和链化合物的合成和表征，重点是确定导致高磁各向异性势垒的因素；(b)将已知具有自旋交叉行为的铁（II）配合物掺入到这些化合物中，可能导致光开关单分子和单链磁铁的第一个例子；(c)钒（II/III）或铁（II/III）混合价通过双重交换机制导致能量隔离良好的高自旋基态的高对称、多核咪唑盐桥接团簇的合成；(d)合成具有严格轴对称的镧系和锕系配合物，这可以提供产生大弛豫势垒的手段；(e)对选定的三角锥体铁（II）配合物配体场的操纵，以及由此产生的零场分裂参数。总之，龙博士和他的团队将为合成新的单分子磁体制定总体策略，这些磁体有望揭示高密度信息存储和基于自旋的分子电子学的潜在兴趣的新型磁性行为。这项研究的广泛影响包括合成技术的遗产，具有潜在技术重要性的新材料的创造，以及无机材料合成和表征方面的博士后、研究生和本科生的教育和培训。作为一项相关的教育活动，龙博士将继续努力在加州大学伯克利分校化学系内创建一个材料化学专业。

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.