In this project funded by the Chemical Synthesis program of the Chemistry Division, Professor John Brennan of Rutgers University probes the fundamental chemistry of the actinide elements combined with the chalcogens sulfur, selenium, and tellurium, including the synthesis and characterization of both molecular and nanoscale materials. An understanding of how actinides interact with these chalcogens improves our ability to separate actinide ions in nuclear fuel reprocessing and environmental waste remediation.
The project begins with the synthesis and characterization of select molecular actinide compounds with a variety of chalcogenolate ligands. A series of molecules with potential covalent bonding character are targeted in order to evaluate how the metal, oxidation state, chalcogenolate, and Lewis base donors influence structure and bonding. These will serve as model systems for theoretical calculations to uncover the nature of the bonding and to predict the chemical reactivity in actinide systems. The molecular products are used as starting materials in the low-temperature synthesis of nanoscale actinide clusters and solid-state materials. Both ionic (oxide, fluoride) and covalent (sulfide, selenide, telluride) ligands are incorporated into cluster cores, with chalcogenolate ligands that cap the cluster surface and inhibit the formation of solid-state products. The relationships between the electronic and magnetic properties of actinide molecules, nanoscale clusters, and solid-state materials are defined by measurements on these molecular chalcogenolate and nanoscale products. The multidisciplinary nature of this work affords undergraduate and graduate students an entrée to a range of potential career paths.
