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Updated: Jun 29, 2025
Nucleoside Triphosphates - From Synthesis to Biochemical Characterization
Published on: April 3, 2014
Speciation of Technetium Dibutylphosphate in the Third Phase Formed in the TBP/HNO3 Solvent Extraction System
Jonathan George1, Ramsey Salcedo2,3,4, Rachel Greenberg2,3,4
1Radiochemistry Program, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154, United States.
Abstract:
The speciation of technetium in the nitric acid/dibutylphosphoric acid (HDBP)-n-dodecane system was studied by extended X-ray absorption fine structure (EXAFS) spectroscopy and theoretical methods. Tetravalent technetium, produced by the hydrazine reduction of TcO4- in 3 M HNO3, was extracted by HDBP in n-dodecane (30% by volume). During extraction, the splitting of the organic phase into a heavy phase and a light phase was observed. EXAFS analysis is consistent with the presence of Tc(NO3)3(DBP)(HDBP)2 in the light phase and Tc(NO3)2(DBP)2(HDBP)2 in the heavy phase. Density functional theory calculations at the B3LYP/6-31G* level confirm the stability of the proposed species and indicate that stereoisomers -mer- and fac-Tc(NO3)3(DBP)(HDBP)2 for the light phase and cis- and trans-Tc(NO3)2(DBP)2(HDBP)2 for the heavy phase] could coexist in the system (in the n-dodecane solution). Mechanisms of formation of Tc(NO3)3(DBP)(HDBP)2 and Tc(NO3)2(DBP)2(HDBP)2 are proposed.
