Challenging conventional f-element separation chemistry--reversing uranyl(VI)/lanthanide(III) solvent extraction...

Area of Science:

• Coordination Chemistry
• Radiochemistry
• Separation Science

Background:

• Schiff base ligands are versatile chelators.
• Uranyl(VI) and lanthanide ions present separation challenges.
• Solvent extraction is a common separation technique.

Purpose of the Study:

• To synthesize and characterize a water-soluble tetradentate Schiff base, H2salen-SO3.
• To investigate the coordination behavior of H2salen-SO3 with uranyl(VI) and trivalent lanthanide cations.
• To explore the potential of H2salen-SO3 for novel separation processes.

Main Methods:

• Synthesis of N,N'-bis(5-sulfonatosalicylidene)-diaminoethane (H2salen-SO3).
• Coordination studies with uranyl(VI) and lanthanide salts.
• Analysis of binding affinities and selectivities.

Main Results:

• H2salen-SO3 readily coordinates to uranyl(VI) cations.
• Coordination to trivalent lanthanide cations is significantly less pronounced.
• The ligand exhibits selective binding towards uranyl(VI).

Conclusions:

• H2salen-SO3 demonstrates high selectivity for uranyl(VI) over lanthanides.
• This selectivity allows for the reversal of conventional solvent extraction properties.
• The findings open possibilities for novel separation and purification processes involving actinides and lanthanides.