Phosphonate-Based Aza-Macrocycle Ligands for Low-Temperature, Stable Chelation of Medicinally Relevant Rare Earth Radiometals and Radiofluorination.

Radioisotopes of fluorine (F), scandium (Sc, Sc), lutetium (Lu), and yttrium (Y, Y) have decay properties ideally suited for targeted nuclear imaging and therapy with small biologics, such as peptides and antibody fragments. However, a single-molecule strategy to introduce these radionuclides into radiopharmaceuticals under mild conditions to afford inert in vivo complexes is critically lacking. Here, we introduce HL2 and HL3, two small-cavity macrocyclic chelator structural isomers bearing a single phosphonate functional group.

Recycling of Cr electroplated targets for Mn production.

Mn is a promising radionuclide for positron emission tomography (PET). Enriched Cr targets are required to minimize formation of Mn radioisotopic impurities during production with proton beams. The need for radioisotopically pure Mn, accessibility and cost of Cr, sustainability of the radiochemical process, and potential for iterative purification of target materials motivate this development of recyclable, electroplated Cr metal targets and radiochemical isolation and labeling with resulting >99.