Establishing Bonding and Reactivity in Organometallic Uranium Species

Purdue University, West Lafayette IN

Investigators

Abstract

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.