Isothermal transport coefficients in concentrated aqueous solutions of unsymmetrical electrolytes:  lanthanum trichloride at 25.degree.C

Weingaertner, Hermann; Braun, Bernd M.; Schmoll, Jutta M.

doi:10.1021/j100288a041

Cited by 26 publications

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“…(1) and (2) The present measurements agree satisfactorily with those obtained by Weingärtner et al [16] for LaCl3 solutions for higher concentrations. Numerical application of Eqs.…”

Section: Experimental Methodssupporting

confidence: 92%

Self-Diffusion Coefficients and Structure of the Trivalent Transplutonium Ion Berkelium(249) in Aqueous Solution

Latrous

Olivier²,

Chemla³

1988

Zeitschrift Für Physikalische Chemie

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Self-diffusion (coefficients) \ Solvation / Actinide / Lanthanide / Trivalent (aqueous ions) Self-diffusion coefficients D of the trivalent aquo ion Bk3+ have been determined in aqueous Nd(C104)3-HC104 solutions (pH 2.5) at 25 C by the open-end capillary method.The variation of D versus the square root of the concentration of inactive solution is not linear in the studied range of concentration. The limiting value D0 at zero ionic strength is 5.95 10"6 cm2 s_1. The curve D =/([/C) relating to Bk3+ can be compared to those of Am3 + (241) and Eu3 + (152) obtained under the same conditions. Moreover, it may be argued that the Bk3 + , Am3+ and Eu3+ ions in solution have the same hydration as tripositive other 5f and 4/ions in the absence of hydrolysis, complexing or ion pairing at pH 2.5. The present study contributes to show the analogy of solvation structure of trivalent actinides ion in aqueous solution at pH 2.5 with that of the lanthanides trivalent ions as a help for predicting the thermodynamic properties.Es wurden Selbstdiffusionskoeffizienten D des dreiwertigen Aquo-Ions Bk3 + in wäßrigen Nd(C104)3H004-Lösungen bei pH 2.5 mit einer Rapillartechnik bei 25°C bestimmt. Im untersuchten Konzentrationsbereich wurde keine lineare Abhängigkeit der Selbstdiffusionskoeffizienten von der Wurzel der Konzentration der inaktiven Lösung beobachtet. Der Grenzwert des Selbstdiffusionskoeffizienten bei unendlicher Verdünnung beträgt 5,95 10-6 cm2 s_1. Die für Bk3+ gefundene Kurve D = f (yC) kann mit unter den gleichen Bedingungen erhaltenen Kurven für Am3 + und Eu3 + verglichen werden. Zusätzlich kann angenommen werden, daß Bk3 + , Am3 + -und Eu3 +-Ionen in Abwesenheit von Hydrolyse, Ionenpaarund Komplexbildung bei pH 2,5 dieselben Hydratationseigenschaften zeigen wie andere Ionen der 5/und 4/-Reihe. Die Messungen weisen daher auf die Analogie zwischen der Solvatationsstruktur der dreiwertigen Ionen der Aktinidenreihe und derjenigen der Lanthanidenreihe bei pH 2,5 hin und können damit auch einen Beitrag zur Vorhersage der thermodynamischen Eigenschaften leisten.

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“…(1) and (2) The present measurements agree satisfactorily with those obtained by Weingärtner et al [16] for LaCl3 solutions for higher concentrations. Numerical application of Eqs.…”

Section: Experimental Methodssupporting

confidence: 92%

Self-Diffusion Coefficients and Structure of the Trivalent Transplutonium Ion Berkelium(249) in Aqueous Solution

Latrous

Olivier²,

Chemla³

1988

Zeitschrift Für Physikalische Chemie

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“…Consider the aqua ion [Gd(H 2 O) 8 ] 3+ . The distance of closest approach of two Gd 3+ ions can be estimated to be twice the Gd−H distance, which can be estimated at 3.05 Å from neutron diffraction data for Sm 3+ and Nd 3+ solutions. , The diffusion coefficient for the [Gd(H 2 O) 8 ] 3+ should be similar to the limiting value of 6 × 10 -10 m 2 s -1 at 298 K found for La 3+ in aqueous LnCl 3 solution, and the diffusion coefficient for motion of one complex relative to another should be twice this value. Thus with a GdGd ≈ 6.1 Å and D GdGd ≈ 1.2 × 10 -9 m 2 s -1 one can estimate τ GdGd ≈ 3 × 10 -10 s at 298 K whereas, from Figure , the transverse electronic relaxation time is longer than 10 -9 s at the same temperature, so that τ d /T i e will be small compared to ω S τ d and the effect of the electronic relaxation rates on the spectral density functions will be minor.…”

Section: Resultsmentioning

confidence: 83%

Structural and Dynamic Parameters Obtained from ¹⁷O NMR, EPR, and NMRD Studies of Monomeric and Dimeric Gd³⁺ Complexes of Interest in Magnetic Resonance Imaging: An Integrated and Theoretically Self-Consistent Approach¹

et al. 1996

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We present the results of new and previously published 17O NMR, EPR, and NMRD studies of aqueous solutions of the Gd3+ octaaqua ion and the commercial MRI contrast agents [Gd(DTPA)(H2O)]2- (MAGNEVIST, Schering AG, DTPA = 1,1,4,7,7-pentakis(carboxymethyl)-1,4,7-triazaheptane), [Gd(DTPA-BMA)(H2O)] (OMNISCAN, Sanofi Nycomed, DTPA-BMA = 1,7-bis[(N-methylcarbamoyl)methyl]-1,4,7-tris(carboxymethyl)-1,4,7-triazaheptane), and [Gd(DOTA)(H2O)]- (DOTAREM, Guerbet, DOTA = 1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecane). High-field EPR measurements at different concentrations give evidence of an intermolecular dipole−dipole electronic relaxation mechanism that has not previously been described for Gd3+ complexes. For the first time, the experimental data from the three techniques for each complex have been treated using a self-consistent theoretical model in a simultaneous multiple parameter least-squares fitting procedure. The lower quality of the fits compared to separate fits of the data for each of the three techniques shows that the increase in the number of adjustable parameters is outweighed by the increased constraint on the fits. The parameters governing the relaxivity of the complexes are thus determined with greater confidence than previously possible. The same approach was used to study two dimeric Gd3+ complexes [pip{Gd(DO3A)(H2O)}2] and [bisoxa{Gd(DO3A)(H2O)}2] (pip(DO3A)2 = bis(1,4-(1-(carboxymethyl)-1,4,7,10-tetraaza-4,7,10-tris(carboxymethyl)-1-cyclododecyl-1,4-diazacyclohexane, bisoxa(DO3A)2 = bis(1,4-(1-(carboxymethyl)-1,4,7,10-tetraaza-4,7,10-tris(carboxymethyl)-1-cyclododecyl))-1,10-diaza-3,6-dioxadecane) that are being developed as potential second-generation MRI contrast agents. These dimeric complexes are expected to have higher relaxivities than the monomeric contrast agents, due to their longer rotational correlation times. The results of this study show that further relaxivity gain for these complexes will be hindered by the slow rate of water exchange on the complexes. High-field EPR measurements suggest that there is a previously unrecorded intramolecular dipole−dipole mechanism of electronic relaxation, but that this additional contribution to electronic relaxation is of minor importance compared to the limiting effect of water exchange rates in the determination of proton relaxivity in MRI applications.

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“…These coefficients together with the velocity cross correlation coefficients (which can be calculated by extending the formalism of a ternary system [23] to a pentanary system) will characterize the coupled pairwise diffusion of ions and can be related to the corresponding solvent averaged ion-ion potentials. A calculation of these coefficients over the whole concentration range and comparison with experimental values given for 1:1, 1:2 and 1:3 electrolyte systems [24][25][26] may help to give a satisfactory description of the structure of these systems in correlation with their environment and to gain much information so that we can explain how the dynamical properties of the diffusing species govern the local and global structure of its environment during transport for a complex liquid system consisting of dissociating electrolyte.…”

Section: Resultsmentioning

confidence: 99%

Anomalies in the ion transport of phosphoric acid in water and heavy-water environments

Chakrabarti

1996

J. Phys.: Condens. Matter

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This paper presents the experimentally determined precise transport data - (tracer) diffusion coefficients in both water and heavy-water environments, together with molar conductivity and viscosity of (ortho)phosphoric acid in water over an extended concentration range at [Formula: see text]. The concentration (c) dependence of the diffusion coefficients (D), viscosity [Formula: see text] and molar conductivity [Formula: see text] have been analysed. An anomalous depression in the D - [Formula: see text] curve for both [Formula: see text] - [Formula: see text] and [Formula: see text] - [Formula: see text] systems in the neighbourhood of 0.8 M is observed, which is complementary to the sudden sharp rise observed in the [Formula: see text] curve in the neighbourhood of 0.8 M. Although the occurrence of such an anomaly could be inferred from the earlier conductance, e.m.f. and diffusion data, it was never conclusively inferred earlier. This new set of diffusion and viscosity data clearly delineates anomalies in the ion transport of phosphoric acid.

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Isothermal transport coefficients in concentrated aqueous solutions of unsymmetrical electrolytes: lanthanum trichloride at 25.degree.C

Cited by 26 publications

References 1 publication

Self-Diffusion Coefficients and Structure of the Trivalent Transplutonium Ion Berkelium(249) in Aqueous Solution

Self-Diffusion Coefficients and Structure of the Trivalent Transplutonium Ion Berkelium(249) in Aqueous Solution

Structural and Dynamic Parameters Obtained from ¹⁷O NMR, EPR, and NMRD Studies of Monomeric and Dimeric Gd³⁺ Complexes of Interest in Magnetic Resonance Imaging: An Integrated and Theoretically Self-Consistent Approach¹

Anomalies in the ion transport of phosphoric acid in water and heavy-water environments

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Isothermal transport coefficients in concentrated aqueous solutions of unsymmetrical electrolytes: lanthanum trichloride at 25.degree.C

Cited by 26 publications

References 1 publication

Self-Diffusion Coefficients and Structure of the Trivalent Transplutonium Ion Berkelium(249) in Aqueous Solution

Self-Diffusion Coefficients and Structure of the Trivalent Transplutonium Ion Berkelium(249) in Aqueous Solution

Structural and Dynamic Parameters Obtained from 17O NMR, EPR, and NMRD Studies of Monomeric and Dimeric Gd3+ Complexes of Interest in Magnetic Resonance Imaging: An Integrated and Theoretically Self-Consistent Approach1

Anomalies in the ion transport of phosphoric acid in water and heavy-water environments

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Product

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Structural and Dynamic Parameters Obtained from ¹⁷O NMR, EPR, and NMRD Studies of Monomeric and Dimeric Gd³⁺ Complexes of Interest in Magnetic Resonance Imaging: An Integrated and Theoretically Self-Consistent Approach¹