Scientists in the Netherlands and Germany have synthesised a series of new pyrazine substituted ligands that are promising for actinide separation.
The team used the ligands to differentiate trivalent actinides from lanthanides, with a very good selectivity for Am3+ over Eu3+ with separation factors up to 40 at pH 1 at 0.01 mol/L ligand concentration.
The ligands are resistant to strong acids and water soluble, which makes them ideal for the innovative SANEX concept (Selective ActiNide Extraction).
The team says: ‘It is basically a DIAMEX (DIAMide EXtraction) process (An(III) and Ln(III) coextraction) with selective back extraction of An(III) from the loaded organic phase. Instead of a water-soluble complexing agent such as diethylene triamine pentaacetic acid, which requires in most cases buffering agents to adjust the pH, the search is for stronger acid resistant water-soluble ligands.’
Palladium–catalyzed cross-coupling of various phosphorus pronucleophiles with chloropyrazines: synthesis of novel Am(III)-selective extractants
W. Verboom, Nicolai I. Nilishkin, Jurriaan Huskens, Giuseppe Modolo, Jana Assenmacher and Andreas Wilde