Oxidation is the process where atoms lose electrons during a chemical reaction. Among the radioactive elements, neptunium and plutonium are much harder to oxidize than uranium. To study these elements, scientists have designed donor ligands — molecules that contribute electron density to metal centers. This allows scientists to stabilize these metals as they become more electron-poor. Accessing and studying the high oxidation states of uranium, neptunium, and plutonium complexes helps scientists understand their chemical reactivities—how easily they form new chemical compounds. These studies can shed light on how radioactive materials may behave in nuclear waste streams and waste storage. This study summary was written by Henry La Pierre, associate professor in the School of Chemistry and Biochemistry and Director of the National Nuclear Security Administration Transuranic Chemistry Center of Excellence.