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Volume 67, Nº 3 (2025)
Articles
Reaction of Technetium(I) Tricarbonyl Hexafluoroacetylacetonate Complexes with CCl4: Formation and Crystal Structure of [99ТсСl(СО)3(РРh3)2] Stereoisomers and of fac-[99ТсСl(СО)3(С5Н5N)2]
Resumo
In the course of prolonged interaction in the system consisting of [99Тс(hfa)(СО)4] (hfa is the anion of 1,1,1,5,5,5-hexafluoroacetylacetone), triphenylphosphine (РРh3) or pyridine (py), and CCl4, the hfa anion is gradually displaced by the chloride ion with the formation of the complexes fac- and mer-[99ТсСl(СО)3(РРh3)2] and fac-[99ТсСl(СО)3(py)2]. The crystal and molecular structures of the complexes were determined. The complex fac [99ТсСl(СО)3(РРh3)2] is the first structurally confirmed example of technetium(I) tricarbonyl bis(triphenylphosphine) complexes of facial structure.
Radiochemistry. 2025;67(3):185-194
185-194
The Action of Oxidizing Agents on Neptunium(VI) in Acid Solutions
Resumo
In solutions with pH 1.5–2.5, terbium(IV) stabilized by anions of unsaturated phosphotungstate K10P2W17O61
10–, slowly oxidizes NpO2
2+·5H2O. During oxidation, the resulting Np(VII) cation retains the Np(VI) configuration; i.e., it remains a pentagonal bipyramid. Therefore, the oxidation potential of the Np(VII)/(VI) pair is higher than the potential of the pair in which Np(VII) obtained by acidifying the Np(VII) anion retains the octahedral configuration. The high potential of Np(VII) with the pentagonal bipyramidal structure makes Np(VII) unstable. It was impossible to obtain it using strong oxidizing agents such as persulfate, perxenate, and xenon difluoride. Probably, pulse radiolysis will be an effective method for oxidizing Np(VI) in deaerated solutions at pH 1.5–3, containing persulfate or XeO3.
Radiochemistry. 2025;67(3):195-198
195-198
Extraction of Lanthanides(III) from Solutions of Mineral Acids with Solutions of N,N' -Dimethyl-N,N'-dicyclohexyldiglycolamide Complex with Bis[(trifluoromethyl)sulfonyl]imide
Resumo
Extraction of lanthanides(III) from aqueous solutions of nitric and perchloric acids and bis[(trifluoromethyl)sulfonyl]imide with solutions of N,N'-dimethyl-N,N'-dicyclohexyldiglycolamide in organic solvents was studied depending on the concentration of acids in the aqueous phase. The stoichiometry of the extracted complexes was determined. It was found that the transformation of N,N'-dimethyl-N,N'-dicyclohexyldiglycolamide into a complex with bis[(trifluoromethyl)sulfonyl]imide leads to a significant increase in the extraction of lanthanide(III) ions from solutions of nitric, hydrochloric, sulfuric, and phosphoric acids.
Radiochemistry. 2025;67(3):199-204
199-204
Extraction of Lutetium with Solutions of 2-Ethylhexyl Hydrogen 2-Ethylhexylphosphonate in Hexane from Nitric Acid Solutions Containing Ytterbium
Resumo
The extraction of lutetium with 0.5–2 M solutions of 2-ethylhexyl hydrogen 2-ethylhexylphosphonate (HEH[EHP]) in hexane from 0.5–2 M solutions of nitric acid containing ytterbium at a lutetium concentration of 0.57 mM (0.1 g/L) and a ratio of lutetium and ytterbium concentrations of 1 : 1 to 1 : 50 was studied. The extraction mechanisms of both lanthanides are identical under the conditions studied. The effect of excess ytterbium on the distribution of lutetium during extraction is due to a decrease in the concentration of the free extractant. A model describing the dependence of the lutetium distribution coefficient on the concentration of ytterbium in the aqueous phase at various concentrations of the extractant and nitric acid is proposed; it satisfactorily agrees with the experimental data.
Radiochemistry. 2025;67(3):205-213
205-213
Evaluation of the Efficacy of N-Succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) as a Synthon for Labeling Peptides, Illustrated by the Reaction with Glutathione
Resumo
The conjugation of N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB), a widely used radiosynthon for labeling biologically complex molecules for use as radiopharmaceuticals (RPs) in positron emission tomography (PET), with a model tripeptide, glutathione (GSH), was studied. [18F]SFB was prepared using the previously developed method of direct copper(II)-mediated radiofluorination of arylpinacolboronate as a labeling precursor. The efficiency of the conjugation of [18F]SFB, which was recovered from the reaction mixture by solid-phase extraction (SPE) on disposable cartridges, with GSH in an acetonitrile/phosphate buffered mixture with pH 8.4 depended on the ratio of the aqueous and nonaqueous phases and the peptide concentration. With equal volumes of the components (0.5 mL) and a GSH concentration of 1.0 mg/mL, the conjugation yield of 97% was achieved. This serves as further evidence of the efficiency of SPE purification, which removes chemical impurities that could otherwise compete in the conjugation reaction. This purification method using disposable cartridges can be easily adapted to any automated modules, including cassette ones. This contributes to the more effective use of [18F]SFB in synthesizing radiopharmaceuticals based on complex biomolecules.
Radiochemistry. 2025;67(3):214-220
214-220
Immobilization of Boron-Containing Radioactive Waste from Nuclear Power Plants in Magnesium Potassium Phosphate Compound
Resumo
Samples of magnesium potassium phosphate compound containing a simulant of boron-containing evaporator bottom after concentration of liquid radioactive waste from nuclear power plants were synthesized. The possibility of solidifying up to 14 wt % evaporator bottom simulant components into a compound containing 15–20 wt % wollastonite was demonstrated. The phase composition of the samples obtained, their compressive strength, resistance to thermal cycles, water resistance, and hydrolytic stability were determined. The integral leaching rate of 137Cs is 5.7 × 10−4 g/(cm2 day), and the leaching index is 10.7. The quality indicators of the compound obtained meet the regulatory requirements for a compound for solidifying radioactive waste.
Radiochemistry. 2025;67(3):221-229
221-229
Influence of Sodium Aluminum Iron Phosphate Glass Composition on Its Resistance to Leaching
Resumo
The influence of the content of structure-forming components of sodium aluminum iron phosphate glass on its phase composition, structure, and resistance to leaching at elevated temperatures as necessary characteristics of vitrified iron-containing high-level waste during its deep disposal was studied. It was found that the samples studied (mol %), 40.0Na2O–12.5Al2O3–12.5Fe2O3–35.0P2O5, 35.0Na2O–12.5Al2O3–12.5Fe2O3–40.0P2O5, and 35.0Na2O–10.0Al2O3–10.0Fe2O3–45.0P2O5, are represented by a single amorphous glass phase and have high hydrothermal stability. The leaching rate of sodium and phosphorus from the above samples under semidynamic (on the 28th day) and dynamic (on the 10th day) conditions at 90 and 95°C, respectively, was about 10−5 g/(cm2 day), that of aluminum, within the range (2–10) × 10−6 and (0.6–2) × 10−5 g/(cm2 day), respectively, and that of iron, within the range (7–12) × 10−7 and (0.4–3) × 10−6 g/(cm2 day), respectively.
Radiochemistry. 2025;67(3):230-238
230-238
A Study of the Radionuclide Diffusion in Clay Materials Taking into Account the Coupled Physicochemical Processes
Resumo
In an experimental study of the diffusion of manmade radionuclides in pore solutions of compacted clay materials, in addition to the sorption retention on the surface of clay minerals, which is typical for many radionuclides, effects caused by other physicochemical processes occurring simultaneously with the diffusion were observed. These processes, called coupled, are associated mainly with the precipitation—dissolution of radionuclide compounds in pore solutions, as well as with the sorption—desorption of radionuclide particles on the surface of solid phases as a result of their diffusion transfer in the pore medium together with chemically contrasting components of leachates of technogenic materials used in the radioactive waste disposal. Without taking into account the coupled processes, it is impossible to correctly interpret the experimental results, as well as to reliably predict the migration of manmade radionuclides and justify the safety of radioactive waste disposal facilities.
Radiochemistry. 2025;67(3):239-253
239-253
Comprehensive Method for Sorption Concentration of Radionuclides from Seawater
Resumo
The study evaluated the possibility and efficiency of sorption of artificial (137Cs), natural (210Pb, 210Po, 226Ra, 228Ra, 234Th), and cosmogenic (7Be, 32P, 33P) radionuclides from large volumes of seawater using various types of sorbents. The sorption of the radionuclides studied was scaled up and optimized, with optimal parameters for sorption concentration being established. Based on the obtained data, a comprehensive method was developed and tested for simultaneous concentration of a wide range of radionuclides from seawater using the most efficient sorbents. The study demonstrated the possibility of concentrating multiple radionuclides from a single sample, which significantly simplifies sampling procedures and field research.
Radiochemistry. 2025;67(3):254-264
254-264