Search

Periodically arranging coordination‐distinct actinides into one crystalline architecture is intriguing but of great synthetic challenge. We report a rare example of a heterobimetallic actinide metal–organic framework (An‐MOF) by a unique reaction‐induced preorganization strategy. A thorium MOF (SCU‐16) with the largest unit cell among all Th‐MOFs was prepared as the precursor, then the uranyl was precisely embedded into the MOF precursor under oxidation condition. Single crystal of the resulting thorium‐uranium MOF (SCU‐16‐U) shows that a uranyl‐specific site was in situ induced by the formate‐to‐carbonate oxidation reaction. The heterobimetallic SCU‐16‐U exhibits multifunction catalysis properties derived from two distinct actinides. The strategy proposed here offers a new avenue to create mixed‐actinide functional material with unique architecture and versatile functionality. [ABSTRACT FROM AUTHOR]

Three phosphine oxide functionalized pillar[5]arenes were dissolved in 1‐butyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][Tf2N]), a room‐temperature ionic liquid, and the solutions were used to extract representative tri‐, tetra‐ and hexavalent actinide ions, namely Am3+, Pu4+ and UO22+ ions, from nitric acid feeds. Although the extraction of Am3+ and UO22+ ions decreased with increasing feed acid concentration, the opposite trend was observed for Pu4+. The extraction of the actinide ions followed the trend Pu4+ > UO22+ > Am3+ at 3 m HNO3, and the extraction efficiency of the ligands followed the trend LIII > LII > LI with decreasing spacer lengths. The extraction mechanism conformed to the “solvation” type usually encountered in the case of molecular diluents. The nature of the extracted species was ascertained by “slope analysis”, in which the ligand, nitrate ion and C4mim+ ion concentrations were varied, as well as luminescence spectroscopic measurements. The possibility of recycling of the ionic‐liquid‐based solvent systems was evaluated by carrying out back‐extraction as well as radiolytic degradation studies. [ABSTRACT FROM AUTHOR]