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Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
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A hydrolytically stable complexant for minor An separation from Ln in process relevant diluents
Lesta S Fletcher1, Mariah L Tedder1, Samiat O Olayiwola1
1Department of Chemistry, Tennessee Technological University, Cookeville, TN 38505-0001, USA. jcarrick@tntech.edu.
Chemical Communications (Cambridge, England)
|May 9, 2024
Summary
New bis-1,2,4-triazine complexants show improved solubility and stability for selective minor actinide extraction from nuclear waste. These compounds effectively separate actinides from lanthanides, overcoming limitations of previous BTP complexants.
Area of Science:
- Nuclear Chemistry
- Radiochemistry
- Separation Science
Background:
- Bis-1,2,4-triazine (BTP) complexants are crucial for separating minor actinides from nuclear waste.
- Limitations of current BTP complexants include poor solubility in nonpolar diluents and susceptibility to hydrolysis.
- Developing stable and soluble complexants is essential for efficient nuclear waste reprocessing.
Purpose of the Study:
- To evaluate novel bis-1,2,4-triazine complexants with alkoxy-functionalized phenyl substituents.
- To assess the chemoselective extraction of minor actinides over lanthanides in simulated high-level waste.
- To overcome solubility and stability barriers associated with traditional BTP complexants.
Main Methods:
- Synthesis of bis-1,2,4-triazine complexants with specific phenyl substituents.
- Solubility tests in nonpolar diluents (kerosene, isooctanol) and contact with nitric acid.
- Liquid-liquid extraction experiments to determine selectivity for actinides (e.g., 241Am3+) over lanthanides (e.g., 154Eu3+).
- Spectroscopic analysis to confirm complexant structure and performance.
Main Results:
- The novel BTP complexants exhibit excellent solubility in both kerosene and isooctanol.
- No precipitates, emulsions, or third phases formed upon contact with nitric acid, indicating high hydrolytic stability.
- Chemoselective extraction of actinides over lanthanides was maintained, with successful separation of 241Am3+ from 154Eu3+.
- The functionalized BTP complexants overcome key limitations of existing BTP systems.
Conclusions:
- Alkoxy-functionalized phenyl-substituted BTP complexants offer a promising solution for selective minor actinide extraction.
- These complexants demonstrate enhanced solubility and hydrolytic stability, crucial for industrial applications in nuclear waste management.
- The developed BTP complexants represent a significant advancement in reprocessing technologies for high-level radioactive waste.
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