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Le Naour C, Maloubier M, Aupiais J. The speciation of protactinium since its discovery: a nightmare or a path of resilience. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2021-1126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
This review concerns the speciation of protactinium in aqueous solution under its both oxidation states +IV and +V. Emphasis is placed on experimental data obtained at trace level but also in macroscopic amount leading to the determination of thermodynamic and structural data. Thus, the complexation of Pa(V) with mineral acids and organic acids, mainly polyaminocarboxylic acids (iminodiacetic acid [IDA], nitrilotriacetic acid [NTA], ethylenediaminetetraacetic acid [EDTA] and diethylenetriaminepentaacetic acid [DTPA]) are highlighted and compared. The review also includes the actual knowledge about the Pa(IV) aqueous chemistry pinpointing its spectroscopic features.
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Affiliation(s)
- Claire Le Naour
- Université Paris-Saclay, CNRS/IN2P3, IJCLab , 91405 Orsay , France
| | - Melody Maloubier
- Université Paris-Saclay, CNRS/IN2P3, IJCLab , 91405 Orsay , France
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Gäggeler HW, Eichler B, Jost DT, Eichler R. On the volatility of protactinium in chlorinating and brominating gas media. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2021-1128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A multi-target recoil chamber technique was applied to study online chemical properties of protactinium in chlorinating and brominating gas media using 226Pa (T
1/2 = 1.8 min) decaying by alpha emission (74%) and β+/EC decay (26%). A 58 MeV proton beam passing 15 × 50 μg/cm2 thick 232Th targets enabled production of 226Pa formed in the reaction 232Th(p,7n). Isothermal gas chromatography in quartz columns allowed for the determination of adsorption enthalpies of oxohalides and pure halides of Pa5+ compounds. On the basis of empirical correlations, these adsorption enthalpies (ΔH0
ads) could be converted to sublimation enthalpies (ΔH0
subl). Resulting values for the assumed compounds PaCl5, PaOCl3, PaBr5, and PaOBr3 were 113 ± 15, 329 ± 16, 165 ± 5 and 235 ± 17 kJ/mol, respectively. These values are rather similar to known ΔH0
subl data for group-5 elements Nb, Ta and Db in support of the assumption that Pa is a pseudo-group 5 element.
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Affiliation(s)
- Heinz W. Gäggeler
- Labor für Radiochemie, Paul Scherrer Institut , 5232 Villigen , Switzerland
- Departement für Chemie und Biochemie , Universität Bern , 3012 Bern , Switzerland
| | - Bernd Eichler
- Labor für Radiochemie, Paul Scherrer Institut , 5232 Villigen , Switzerland
| | - Dieter T. Jost
- Labor für Radiochemie, Paul Scherrer Institut , 5232 Villigen , Switzerland
| | - Robert Eichler
- Labor für Radiochemie, Paul Scherrer Institut , 5232 Villigen , Switzerland
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