Expanding Reductive Chemistry and Oxidation State Diversity with the Synthetic Chemistry of the Rare Earth Metals

化学系的化学合成计划支持了加州大学欧文分校化学系William J. Evans教授的项目，以研究含有稀土金属（即钪、钇和镧系元素）的化合物。 含有这些金属的分子和材料对于节能照明和磁性设备等技术非常重要，它们已被美国政府指定为战略材料。 埃文斯教授正在利用稀土金属的特殊性质来发现新的方法来完成最基本的化学反应之一，还原化学。 他还试图提高世界上最小的（即，分子）磁体。该项目同时涉及培训下一代科学家研究这些至关重要的金属，并涉及科学界通常代表性不足的群体的人员。稀土元素在日常技术中的无数用途为各级教育的推广计划提供了良好的基础。埃文斯教授是在最近发现的Y 2+，Ho 2+，Er 2+，Tb 2+，Pr 2+，Gd 2+和Lu 2+的第一分子络合物中的七种稀土元素的新氧化态的基础上进行的。 这些离子的混合主量子数4fn 5d 1电子配置的电子结构正在使用计算方法建模。获得新的氧化态与配位环境，允许更高的说谎轨道被填充的一般性正在综合探索。 由于新的氧化态扩大了进行氧化还原化学的机会，埃文斯教授正在研究这些复合物的反应化学和光化学。 这些化合物的混合电子构型可能导致过渡金属和稀土化学的不寻常组合。 的混合配置的化合物的物理性质的影响也正在研究中，因为Ho 2+复合物具有最高的磁化率，11.4 μ-B，曾经观察到的monoclonal复合物。 总的来说，研究人员正在使用合成方法从新的角度探索还原反应性，氧化态多样性和磁性的基本方面。来自不同背景的学生目前参与了该项目，参与者正在花时间开展旨在扩大STEM领域代表性不足群体参与的外联活动。

The Chemical Synthesis Program of the Chemistry Division supports the project by Professor William J. Evans of the Department of Chemistry at the University of California, Irvine, to investigate chemical compounds that contain the rare earth metals, i.e. scandium, yttrium, and the lanthanides. Molecules and materials that contain these metals are important for technologies such as energy efficient lighting and magnetic devices, and they have been designated strategic materials by the U.S. Government. Professor Evans is using the special properties of the rare earth metals to discover new methods to accomplish one of the most fundamental types of chemical reaction, reduction chemistry. He is also trying to improve the performance of the world's smallest (i.e., molecular) magnets. This project simultaneously involves training the next generation of scientists to study these critically important metals and involves personnel from groups commonly underrepresented in science. The myriad uses of the rare earth elements in everyday technologies are providing an excellent basis for outreach programs at all educational levels. Professor Evans is building upon the recent discovery of new oxidation states for seven rare earth elements in the first molecular complexes of Y2+, Ho2+, Er2+, Tb2+, Pr2+, Gd2+, and Lu2+. The electronic structure of these ions with mixed principal quantum number 4fn5d1 electron configurations is being modeled using computational methods. The generality of obtaining new oxidation states with coordination environments that allow higher-lying orbitals to be populated is being explored synthetically. Because new oxidation states expand opportunities to do redox chemistry, Professor Evans is examining the reaction chemistry and photochemistry of these complexes. The mixed electron configuration of these compounds may lead to an unusual combination of transition metal and rare earth chemistry. The influence of the mixed configuration on physical properties of the compounds is also being studied, because the Ho2+ complex has the highest magnetic susceptibility, 11.4 mu-B, ever observed for a monometallic complex. In general the researchers are using synthetic approaches to explore fundamental aspects of reductive reactivity, oxidation state diversity, and magnetism from new perspectives. Students from diverse backgrounds are currently involved in the project, and the participants are spending time in outreach activities directed towards broadening the participation of underrepresented groups in STEM fields.