Selective Crystallization of a Highly Radiation-Resistant Isonicotinic Acid-Based Metal–Organic Framework as a Primary Actinide Waste Form

Isonicotinic acid (INA), as a prototypical N,O-donor bifunctional ligand, has demonstrated its ability to differentiate Th4+ from representative ions for products in spent nuclear fuels (Cs+, Ba2+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Pd2+, ReO4–, La3+, Ce3+, Ce4+, UO22+), yielding an actinide metal–organic framework, Th-INA-1, by selective crystallization. This unprecedented motif with the highest ligand-binding number (i.e., 16) shows promise as a primary waste form due to its structural integrity, especially exposed to β- or γ-irradiation to achieve doses of 6 MGy.