Establishing Bonding and Reactivity in Organometallic Uranium Species

本项目由化学学部化学合成项目资助。普渡大学的苏珊娜·巴特教授研究铀的有机金属化学。有机金属化学是研究含有金属-碳键的化合物的学科，药物、材料和精细化学品的许多进展都是以有机金属化学为基础的。虽然人们对铀的行为已经研究了许多年，但它的有机金属化学性质仍然相当有限。一般来说，金属可以与碳形成一个、两个或三个化学键。本研究制备了含铀碳双键的化合物，并对其反应性进行了研究。在这些发现的基础上，还制备了铀硅和铀氮双键化合物。这些研究为今后开发铀的新用途奠定了基础。此外，该项目还培养铀化学方面的本科生和研究生。这一点非常重要，因为铀化学工作人员正在老龄化，目前很少有年轻科学家在该领域接受培训。巴特教授和她的学生还为高中教师组织了一个科学夏令营，他们的目标是通过动手活动和设计新的演示，让教师掌握铀化学的新技能。使用立体体积大的氢（二甲基吡唑）硼酸盐作为支撑配体，形成铀双（烷基），用作合成物制备铀-烷基、-硅烯和-亚胺配合物。这些化合物使用多种分析技术进行表征，包括多核核磁共振，红外和电子吸收光谱，以及x射线晶体学和计算方法。用氢原子转移法评价了铀氮键的强度，评价了铀氮多键的键强度，并从理论上考察了f轨道在多键中的作用。一个拓展项目将锕系化学引入科学夏令营。

This project is funded by the Chemical Synthesis program of the Chemistry Division. Professor Suzanne Bart, Purdue University, studies the organometallic chemistry of uranium. Organometallic chemistry is the study of compounds that contain metal-carbon bonds and many advances in pharmaceuticals, materials, and fine chemicals are based on organometallic chemistry. While the behavior of uranium has been studied for many years, its organometallic chemistry remains quite limited. In general, metals can form one, two, or three chemical bond to carbon. This study prepares compounds containing uranium carbon double bonds and investigates their reactivity. Building on these findings compounds with uranium silicon and uranium-nitrogen double bonds also are prepared. These studies lay the ground work for the future development of new applications for uranium. In addition, the project trains undergraduate and graduate students in uranium chemistry. This is extremely important as the uranium chemistry workforce is aging and very few young scientists currently receive training in the field. Prof. Bart and her students also organize a science summer camp for high school teachers where they aim to give the teachers new skills in uranium chemistry through hands on activities and the design new demonstrations. Using sterically bulky hydrotris(dimethylpyrazoly)borate as supporting ligands, uranium bis(alkys) are formed as used as synthons to prepare uranium-alkyledene, -silene, and -imido complexes. These compounds are characterized using multiple analytical techniques, including multinuclear NMR, infrared, and electronic absorption spectroscopies, as well as X-ray crystallography and computational methods. The strength of the uranium-nitrogen bonds is assessed using hydrogen atom transfer studies the bond strength of the uranium-nitrogen multiple bonds are assessed and the role of f-orbitals in the multibonds is examined theoretically. An outreach program introduces actinide chemistry into a science summer camp.