In summary, we have prepared and characterized the first molecular Ra 2+ coordination compound in the solid-state by scXRD, to the best of our knowledge. In comparing the Ra 2+ complex to other crystal structures of DB30C10 complexed with Ba 2+ and Sm 2+ , two chemically similar divalent ions, we highlight key differences in their structural conformation and in the lability of coordinated water. Collectively, our results emphasize the disparate coordination chemistries of Ra 2+ and Ba 2+ , such that using Ba 2+ as a nonradioactive surrogate to model the behavior of Ra 2+ in studies must be done so with caution. We anticipate that the crystallization methods reported in this study will guide other researchers in their efforts to advance the solid-state chemistry of Ra 2+ . Additionally, these results in the solid-state complement our solution-state efforts to characterize the complexation thermodynamics of Ra 2+ in aqueous media, and we expect that the combined insight from these studies will be helpful in rationally designing new chelators for Rabased TAT. To advance this endeavor, efforts are ongoing in our lab to synthesize and characterize other related Ra 2+ complexes by scXRD.