To overcome this obstacle and drive forward the development of chelators that can effectively stabilize Ra for targeted alpha therapy (TAT), a better understanding of the structure and bonding of the Ra 2+ ion within coordination complexes is required. Of the few solid-state structural studies reported to date for Ra 2+ , efforts have been confined to the synthesis of simple inorganic Ra 2+ compounds and their characterization by X-ray powder diffraction (pXRD). Although pXRD can rapidly provide data on the symmetry properties of microcrystalline samples and enable a general comparison of the structural similarities between complexes of Ra 2+ and its congeners (e.g., Ba 2+ , Sr 2+ , and Ca 2+ ), this technique is unable to provide precise information regarding metal-ligand bond distances and coordination geometries about the metal center. Furthermore, the ionic salts studied to date offer limited insight into the behavior and structural organization of Ra 2+ with larger, multidentate molecular chelators used in nuclear medicine. Solution-state characterization of Ra 2+ also lags behind most other metals in the Periodic Table, such that the experimental hydration structure of the Ra-aquo ion was only revealed in 2022 using extended X-ray absorption fine structure (EXAFS) spectroscopy. These fundamental studies of Ra 2+ have been sparsely reported because all its isotopes are short-lived, highly radioactive, and available only in small quantities. These features render them difficult to obtain and handle safely on the macroscopic scale necessary for conventional structural characterization studies. Consequently, even 125 years after its first discovery, insight into the coordination chemistry of Ra 2+ is still remarkably scarce.