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Updated: Jan 18, 2026
10:51
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
12.7K
Solvation Structure of 237Np4+ in a Noncomplexing Environment.
Daria V Boglaienko1, Amity Andersen1, John L Fulton1
1Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
Inorganic Chemistry
|September 9, 2025
Summary
Neptunium (Np4+) ion solvation in triflic acid was studied. Results show changes in hydration and potential sulfonate coordination at higher acid concentrations, impacting Np4+ speciation.
Area of Science:
- Solution chemistry
- Actinide chemistry
- Spectroscopy
Background:
- Understanding neptunium speciation is crucial for nuclear waste management.
- The solvation structure of tetravalent neptunium (Np4+) in aqueous solutions is not fully characterized.
- Trifluoromethanesulfonic acid provides a noncomplexing, nonoxidizing environment for studying Np4+.
Purpose of the Study:
- To investigate the solvation structure of Np4+ in aqueous triflic acid.
- To determine the coordination environment and speciation of Np4+ as a function of triflic acid concentration.
- To elucidate the interactions between Np4+ and triflate ions.
Main Methods:
- X-ray absorption spectroscopy (XAS) including XANES and EXAFS.
- Ab initio molecular dynamics (AIMD) simulations.
- Time-dependent density functional theory (TDDFT) calculations.
Main Results:
- Experimental and computational methods provided consistent data.
- TDDFT revealed a previously unreported weak pre-edge feature in Np LIII-edge XANES.
- AIMD simulations showed concentration-dependent changes in the Np4+ hydration shell.
- EXAFS analysis indicated similar Np-O coordination to perchloric acid at low concentrations but multiple Np-O distances at 7 M triflic acid.
Conclusions:
- Np4+ exhibits concentration-dependent solvation in triflic acid.
- Monodentate coordination with sulfonate groups is implied at 7 M triflic acid.
- The formation of proto-neptunyl species is suggested in low-concentration Np4+ solutions.
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