Europium Determination in Rare Earth Mixtures

Foster, D.C.; Kremers, Howard E.

doi:10.1021/ac60084a039

Cited by 15 publications

(2 citation statements)

References 9 publications

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“…Determination of the Eu II Concentration. The exact concentration of the reduced [Eu II (DTPA)(H 2 O)] 3- sample was always determined by a Reinhardt−Zimmermann redox titration. , Therefore, an excess of Fe 2 (SO 4 ) 3 in 0.5 M H 2 SO 4 was saturated with N 2 and then reacted with a known volume of the reduced [Eu II (DTPA)(H 2 O)] 3- solution. The produced Fe II , corresponding to the amount of Eu II , is stable in acidic medium and was titrated with a K 2 Cr 2 O 7 solution.…”

Section: Methodsmentioning

confidence: 99%

Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [Eu^II(DTPA)(H₂O)]³^-and [Gd^III(DTPA)(H₂O)]²^-Complexes (DTPA = Diethylenetriamine Pentaacetate)¹

2000

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The [EuII(DTPA)(H2O)]3- complex (DTPA = diethylenetriamine pentaacetate) has been prepared by controlled potential coulometry from [EuIII(DTPA)(H2O)]2-. [EuII(DTPA)(H2O)]3- is less stable toward oxidation than Eu2+ (aq), as shown by its more negative redox potential (E 1/2 = −1.34 V in comparison to E 1/2 = −0.61 V vs calomel electrode, respectively). Nevertheless, the rate of oxidation was found to be reasonably slow in highly concentrated solutions. Variable-temperature and -pressure, multiple-field 17O NMR and nuclear magnetic relaxation dispersion (NMRD) measurements have been performed on [EuII(DTPA)(H2O)]3- in aqueous solution. The water-exchange rate (k ex 298 = 1.3 × 109 s-1) is 3 orders of magnitude higher than that on the corresponding Gd(III) complex, and it is only slightly smaller than that on the Eu(II) aqua ion. The positive activation volume (ΔV ⧧ = +4.5 cm3 mol-1) indicates a dissociatively activated water-exchange process. The rotational correlation time is slightly longer for [EuII(DTPA)(H2O)]3- as compared to that for [GdIII(DTPA)(H2O)]2-, which is explained by the higher number of water molecules hydrogen-bonded to the carboxylates of the ligand in the highly charged Eu(II) chelate. The electronic relaxation parameters obtained from NMRD and low-field transverse 17O relaxation rates indicate that electron spin relaxation is considerably faster on [EuII(DTPA)(H2O)]3- than on Eu2+ (aq) or on the isoelectronic [GdIII(DTPA)(H2O)]2-. Possibilities to use EuII complexes as MRI contrast agents are discussed.

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Section: Methodsmentioning

confidence: 99%

Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [Eu^II(DTPA)(H₂O)]³^-and [Gd^III(DTPA)(H₂O)]²^-Complexes (DTPA = Diethylenetriamine Pentaacetate)¹

2000

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“…42 The content of the Eu 3+ ions was measured by redox titration. 43 The ratio of Eu 3+ / Dy 3+ /PMP was 0.78 : 0.22 : 1. The emission quantum yield of PED was measured in THF using quinine sulfate in 0.1 M H 2 SO 4 (w = 0.546) as the standard.…”

Section: Methodsmentioning

confidence: 93%

White photoluminescent material based on a functional polysiloxane complex with lanthanide ions (Eu3+ and Dy3+)

2013

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Scandium, Yttrium und die Elemente der seltenen Erden, Röntgenspektralanalyse

Brukl¹,

Faessler²

1956

Elemente Der Dritten Hauptgruppe Teil II Und Der Dritten Nebengruppe

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Europium Determination in Rare Earth Mixtures

Cited by 15 publications

References 9 publications

Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [Eu^II(DTPA)(H₂O)]³^-and [Gd^III(DTPA)(H₂O)]²^-Complexes (DTPA = Diethylenetriamine Pentaacetate)¹

Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [Eu^II(DTPA)(H₂O)]³^-and [Gd^III(DTPA)(H₂O)]²^-Complexes (DTPA = Diethylenetriamine Pentaacetate)¹

White photoluminescent material based on a functional polysiloxane complex with lanthanide ions (Eu3+ and Dy3+)

Scandium, Yttrium und die Elemente der seltenen Erden, Röntgenspektralanalyse

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Europium Determination in Rare Earth Mixtures

Cited by 15 publications

References 9 publications

Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [EuII(DTPA)(H2O)]3-and [GdIII(DTPA)(H2O)]2-Complexes (DTPA = Diethylenetriamine Pentaacetate)1

Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [EuII(DTPA)(H2O)]3-and [GdIII(DTPA)(H2O)]2-Complexes (DTPA = Diethylenetriamine Pentaacetate)1

White photoluminescent material based on a functional polysiloxane complex with lanthanide ions (Eu3+ and Dy3+)

Scandium, Yttrium und die Elemente der seltenen Erden, Röntgenspektralanalyse

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Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [Eu^II(DTPA)(H₂O)]³^-and [Gd^III(DTPA)(H₂O)]²^-Complexes (DTPA = Diethylenetriamine Pentaacetate)¹

Unexpected Differences in the Dynamics and in the Nuclear and Electronic Relaxation Properties of the Isoelectronic [Eu^II(DTPA)(H₂O)]³^-and [Gd^III(DTPA)(H₂O)]²^-Complexes (DTPA = Diethylenetriamine Pentaacetate)¹