SusChEM: Expanding Reductive Chemistry with the Rare Earth Metals

加州大学欧文分校化学系的William J. Evans教授和他的学生将利用稀土金属的独特性质，即镧系元素、钇和钪，探索氧化还原化学的新方面，即构成两种最常见化学反应之一的还原/氧化反应。由于稀土金属不寻常的物理性质，它们在元素周期表中代表了极端，因此它们是扩展这种基本反应类型极限的一组极好的元素。（N2）3-和（NO）2-自由基是通过稀土发现的具有生物、工业和大气意义的双原子分子的新还原形式，其化学性质将被研究。为什么（N2）3-在形成单分子磁体方面如此有效，并且具有迄今为止已知的最高阻断温度，其原因将被继续研究。在探索产生上述阴离子自由基的还原反应时发现的7种新的稀土氧化态，即Y、Ho、Er、Tb、Pr、Gd和Lu的二价阳离子的反应性和物理性质，也将进行研究。此外，将研究最近发现的稀土配合物的还原性光化学反应，该反应足以将二氮还原为阴离子（N=N）2-。由于氧化还原反应是生命中许多过程的核心，并且对太阳能水分解和氮还原等全球可持续性重要过程至关重要，因此这项研究可以对科学和技术产生广泛的影响。更具体地说，基于还原稀土金属的（N2）3-和（NO）2-自由基阴离子的发现对生物、工业和大气中的二氮和氮氧化物化学具有重要意义。（N2）3-自由基也展示了一种合成单分子磁体的新方法，这些磁体在能量利用和数据存储方面可能具有深远的意义。总的来说，该项目允许探索一组未开发的元素，即稀土金属，这是一种具有许多技术应用的宝贵国家资源，同时为学生提供元素化学方面的培训，这对于解决与放射性废物处理有关的问题至关重要，同时培训该领域的下一代学生。

With this award from the Chemical Synthesis (SYN) Program of the Chemistry Division,, Professor William J. Evans of the Department of Chemistry of the University of California, Irvine, and his students will utilize the unique properties of the rare earth metals, i.e., the lanthanides, yttrium, and scandium, to explore new aspects of redox chemistry, i.e., the reduction/oxidation reactions that constitute one of the two most general classes of chemical reactions. Because the rare earth metals represent extremes in the periodic table due to their unusual physical properties, they are an excellent set of elements for expanding the limits of this fundamental reaction type. The chemistry of the (N2)3- and (NO)2- radicals, new reduced forms of diatomic molecules of biological, industrial, and atmospheric significance that were discovered via the rare earths, will be examined. The reasons why (N2)3- is so effective in forming single molecule magnets with the highest blocking temperatures known to date will be pursued. The reactivity and physical properties of seven new rare earth oxidation states, the divalent cations of Y, Ho, Er, Tb, Pr, Gd, and Lu, discovered while exploring the reductive reactions that generated the anionic radicals above, will also be examined. In addition, the recent discovery of reductive photochemistry for rare earth complexes, found in a reaction powerful enough to reduce dinitrogen to the anion (N=N)2-, will be studied.Because redox reactions are central to so many processes in life and are critical to processes important in global sustainability such as solar water splitting and dinitrogen reduction, this research can have a broad impact on science and technology. More specifically, the reductive rare earth metal based discovery of the (N2)3- and (NO)2- radical anions has implications in biological, industrial, and atmospheric dinitrogen and nitrogen oxide chemistry. The (N2)3- radical also has demonstrated a new approach to the synthesis of single molecule magnets, entities that could have far-reaching implications in energy utilization and data storage. In general, this project allows the exploration of an under-developed set of elements, the rare earth metals, which are a valuable national resource with many technological applications, while providing training to students in f element chemistry that is essential to addressing issues associated with radioactive waste disposal while training the next generation of students in this field.