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Yeh, M.; Maddison, Andrew P.; Clark, Sue B.

doi:10.1023/a:1010605900175

Cited by 5 publications

(7 citation statements)

References 22 publications

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“…To allow a comparison between data at different temperatures, the constants in molarity should be converted to the constants in molality. According to the method in the literature, 6 the equilibrium constant of a reaction in molality (K m ) is related to that in molarity (K M ) by eqn (12).…”

Section: Data On Actinide Complexation At Elevated Temperaturesmentioning

confidence: 99%

“…Data on the complexation of trivalent actinides in solution at variable temperatures are extremely scarce. There are only a few studies on the complexation of Am(III) and Cm(III) with carbonate [9][10][11] and chloride 12 (Table 1). In none of the studies is calorimetry used to directly measure the enthalpy of complexation.…”

Section: Trivalent Actinidesmentioning

confidence: 99%

“…Yeh et al determined the stability constants of AmCl 2+ (at 25 and 50 uC) and EuCl 2+ (at 25, 50 and 75 uC) using solvent extraction. 12 The stability constants increased as the temperature was elevated (Table 1). The enthalpies of complexation were calculated by the van't Hoff equation to be about 20 kJ mol 21 for both AmCl 2+ and EuCl 2+ , contradicting some data in the literature that showed the 1 : 1 lanthanide-chloro complexation was exothermic.…”

Section: Trivalent Actinidesmentioning

confidence: 99%

“…The enthalpies of complexation were calculated by the van't Hoff equation to be about 20 kJ mol 21 for both AmCl 2+ and EuCl 2+ , contradicting some data in the literature that showed the 1 : 1 lanthanide-chloro complexation was exothermic. 12 Such discrepancy might be due to the inherent weakness of metal chloro-complexes in the aqueous solution that results in large scatter in the data and makes it difficult to accurately determine the enthalpy by the temperature dependency of the stability constants. Direct measurements of the reaction enthalpy by microcalorimetry could generate more reliable data and help to resolve the discrepancy.…”

Section: Trivalent Actinidesmentioning

confidence: 99%

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Thermodynamics of actinide complexation in solution at elevated temperatures: application of variable-temperature titration calorimetry

Rao

2007

Chem. Soc. Rev.

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Studies of actinide complexation in solution at elevated temperatures provide insight into the effect of solvation and the energetics of complexation, and help to predict the chemical behavior of actinides in nuclear waste processing and disposal where temperatures are high. This tutorial review summarizes the data on the complexation of actinides at elevated temperatures and describes the methodology for thermodynamic measurements, with the emphasis on variable-temperature titration calorimetry, a highly valuable technique to determine the enthalpy and, under appropriate conditions, the equilibrium constants of complexation as well.

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Section: Data On Actinide Complexation At Elevated Temperaturesmentioning

confidence: 99%

Section: Trivalent Actinidesmentioning

confidence: 99%

Section: Trivalent Actinidesmentioning

confidence: 99%

Section: Trivalent Actinidesmentioning

confidence: 99%

See 2 more Smart Citations

Thermodynamics of actinide complexation in solution at elevated temperatures: application of variable-temperature titration calorimetry

Rao

2007

Chem. Soc. Rev.

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“…Literature data on the complexation of trivalent actinides with chloride at increased temperatures are scarce. Yeh et al used a solvent extraction method to study the formation of AmCl 2+ complexs in 1.0 M NaClO 4 at T = 25 and 50 °C . The authors determined a slight increase of log β′ 1 (25 °C)(AmCl 2+ ) = 0.11 ± 0.05 to log β′ 1 (50 °C)(AmCl 2+ ) = 0.38 ± 0.05 in the studied temperature range, yielding a reaction enthalpy of Δ r H = 19.39 ± 7.35 kJ/mol.…”

Section: Introductionmentioning

confidence: 99%

Combined Time-Resolved Laser Fluorescence Spectroscopy and Extended X-ray Absorption Fine Structure Spectroscopy Study on the Complexation of Trivalent Actinides with Chloride at T = 25–200 °C

et al. 2014

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The complexation of trivalent actinides (An(III)) with chloride is studied in the temperature range from 25 to 200 °C by spectroscopic methods. Time-resolved laser fluorescence spectroscopy (TRLFS) is applied to determine the thermodynamic data of Cm(III)-Cl(-) complexes, while extended X-ray absorption fine structure spectroscopy (EXAFS) is used to determine the structural data of the respective Am(III) complexes. The experiments are performed in a custom-built high-temperature cell which is modified for the respective spectroscopic technique. The TRLFS results show that at 25 °C the speciation is dominated mainly by the Cm(3+) aquo ion. Only a minor fraction of the CmCl(2+) complex is present in solution. As the temperature increases, the fraction of this species decreases further. Simultaneously, the fraction of the CmCl2(+) complex increases strongly with the temperature. Also, the CmCl3 complex is formed to a minor extent at T > 160 °C. The conditional stability constant log β'2 is determined as a function of the temperature and extrapolated to zero ionic strength with the specific ion interaction theory approach. The log β°2(T) values increase by more than 3 orders of magnitude in the studied temperature range. The temperature dependency of log β°2 is fitted by the extended van't Hoff equation to determine ΔrH°m, ΔrS°m, and ΔrC°p,m. The EXAFS results support these findings. The results confirm the absence of americium(III) chloride complexes at T = 25 and 90 °C ([Am(III)] = 10(-3) m, [Cl(-)] = 3.0 m), and the spectra are described by 9-10 oxygen atoms at a distance of 2.44-2.48 Å. At T = 200 °C two chloride ligands are present in the inner coordination sphere of Am(III) at a distance of 2.78 Å.

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A critical review of the solution chemistry, solubility, and thermodynamics of europium: Recent advances on the Eu3+ aqua ion and the Eu(III) aqueous complexes and solid phases with the sulphate, chloride, and phosphate inorganic ligands

Jordan

Thoenen

Starke

et al. 2022

Coordination Chemistry Reviews

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Untitled

Cited by 5 publications

References 22 publications

Thermodynamics of actinide complexation in solution at elevated temperatures: application of variable-temperature titration calorimetry

Thermodynamics of actinide complexation in solution at elevated temperatures: application of variable-temperature titration calorimetry

Combined Time-Resolved Laser Fluorescence Spectroscopy and Extended X-ray Absorption Fine Structure Spectroscopy Study on the Complexation of Trivalent Actinides with Chloride at T = 25–200 °C

A critical review of the solution chemistry, solubility, and thermodynamics of europium: Recent advances on the Eu3+ aqua ion and the Eu(III) aqueous complexes and solid phases with the sulphate, chloride, and phosphate inorganic ligands

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