Complexes of Trivalent Lanthanide and Actinide Ions. II. Inner-Sphere Complexes

1965 ◽  
Vol 4 (9) ◽  
pp. 1254-1257 ◽  
Author(s):  
Gregory R. Choppin ◽  
Anthony J. Graffeo
Keyword(s):  
Trivalent Lanthanide ◽  
Inner Sphere ◽  
Actinide Ions ◽  
Inner Sphere Complexes

Quantum chemical study of inner-sphere complexes of trivalent lanthanide and actinide ions on the corundum (0001) surface

2010 ◽  
Vol 98 (9-11) ◽  
pp. 627-634 ◽  
Author(s):  
Robert Polly ◽  
Bernd Schimmelpfennig ◽  
Thomas Rabung ◽  
Mathias Flörsheimer ◽  
Reinhardt Klenze ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Trivalent Lanthanide ◽  
Inner Sphere ◽  
Actinide Ions ◽  
Inner Sphere Complexes

Bond-length distributions for ions bonded to oxygen: Results for the lanthanides and actinides and discussion of the f-block contraction

2017 ◽  
Author(s):  
Olivier Charles Gagné
Keyword(s):  
Bond Length ◽  
Coordination Number ◽  
Lanthanide Ions ◽  
Lanthanide Contraction ◽  
Trivalent Lanthanide ◽  
Actinide Ions

Bond-length distributions have been examined for eighty-four configurations of the lanthanide ions and twenty-two configurations of the actinide ions bonded to oxygen. The lanthanide contraction for the trivalent lanthanide ions bonded to O<sup>2-</sup> is shown to vary as a function of coordination number and to diminish in scale with increasing coordination number.

Thermodynamic properties of trivalent lanthanide and actinide ions in molten mixtures of LiCl and KCl

2012 ◽  
Vol 424 (1-3) ◽  
pp. 17-22 ◽  
Author(s):  
Kazuhito Fukasawa ◽  
Akihiro Uehara ◽  
Takayuki Nagai ◽  
Nobuaki Sato ◽  
Toshiyuki Fujii ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Trivalent Lanthanide ◽  
Actinide Ions

Surface Complexation of Neptunium(V) with Goethite

2006 ◽  
Vol 985 ◽  
Author(s):  
James L Jerden ◽  
A Jeremy Kropf
Keyword(s):  
Sodium Chloride ◽  
Sodium Silicate ◽  
Outer Sphere ◽  
Distribution Coefficients ◽  
Batch Adsorption ◽  
Inner Sphere ◽  
Show Evidence ◽  
X Ray Absorption ◽  
Outer Sphere Complexes ◽  
Inner Sphere Complexes

AbstractBatch adsorption experiments in which neptunium bearing solutions were reacted with goethite (alpha-FeOOH) have been performed to study uptake mechanisms in sodium chloride and calcium-bearing sodium silicate solutions. This paper presents results identifying and quantifying the mechanisms by which neptunium is adsorbed as a function of pH and reaction time (aging). Also presented are results from tests in which neptunium is reacted with goethite in the presence of other cations (uranyl and calcium) that may compete with neptunium for sorption sites. The desorption of neptunium from goethite has been studied by resuspending the neptunium-loaded goethite samples in solutions containing no neptunium. Selected reacted sorbent samples were analyzed by x-ray absorption spectroscopy (XAS) to determine the oxidation state and molecular speciation of the adsorbed neptunium. Results have been used to establish the pH adsorption edge of neptunium on goethite in sodium chloride and calcium-bearing sodium silicate solutions. The results indicate that neptunium uptake on goethite reaches 95% at a pH of approximately 7 and begins to decrease at pH values greater than 8.5. Distribution coefficients for neptunium sorption range from less than 1000 (moles/kg)sorbed / (moles/kg)solution at pH less than 5.0 to greater than 10,000 (moles/kg)sorbed / (moles/kg)solution at pH greater than 7.0. Distribution coefficients as high as 100,000 (moles/kg)sorbed / (moles/kg)solution were recorded for the tests done in calcite equilibrated sodium silicate solutions. XAS results show that neptunium complexes with the goethite surface mainly as Np(V) (although Np(IV) is prevalent in some of the longer-duration sorption tests). The neptunium adsorbed to goethite shows Np-O bond length of approximately 1.8 angstroms which is representative of the Np-O axial bond in the neptunyl(V) complex. This neptunyl(V) ion is coordinated to 5 or 6 equatorial oxygens with Np-O bond lengths of 2.45 angstroms. The absence of a clearly recognizable Np-Fe interaction for the sodium chloride sorption tests suggests that neptunium in these solutions adsorbs as an outer-sphere complex. XAS results from the calcium-bearing sodium silicate sorption tests show evidence for a neptunyl(V) inner-sphere surface complex with a Np-Fe interaction at 3.5 angstroms. Desorption tests indicate that samples in which neptunium is bound as inner-sphere complexes show significant sorption hysteresis relative to samples in which neptunium is bound largely as outer-sphere complexes.

Coordination Chemistry of Trivalent Lanthanide and Actinide Ions in Dilute and Concentrated Chloride Solutions

2000 ◽  
Vol 39 (3) ◽  
pp. 595-601 ◽  
Author(s):  
P. G. Allen ◽  
J. J. Bucher ◽  
D. K. Shuh ◽  
N. M. Edelstein ◽  
I. Craig
Keyword(s):  
Coordination Chemistry ◽  
Chloride Solutions ◽  
Trivalent Lanthanide ◽  
Actinide Ions

Do the lanthanides form inner sphere complexes with ClO4− ions in competition with H2O molecules?

1992 ◽  
Vol 31 (1-2) ◽  
pp. 117-122 ◽  
Author(s):  
E. Huskowska ◽  
J. Legendziewicz ◽  
Th. Schleid ◽  
G. Meyer
Keyword(s):  
Inner Sphere ◽  
Inner Sphere Complexes

Enthalpies of formation of Cr3+(aq) and the inner sphere complexes CrF2+(aq), CrCl2+(aq), CrBr2+(aq), and CrSO4+(aq)

1976 ◽  
Vol 54 (9) ◽  
pp. 1383-1387 ◽  
Author(s):  
Ingemar Dellien ◽  
Loren G. Hepler
Keyword(s):  
Enthalpies Of Formation ◽  
Calorimetric Measurements ◽  
Inner Sphere ◽  
Inner Sphere Complexes

We have carried out calorimetric measurements leading to ΔHf0 = −60 kcal mol−1 for Cr3+(aq). Further calorimetric measurements have led to enthalpies of reaction of Cr3+(aq) with HF(aq), Cl−(aq), Br−(aq), and SO42−(aq) to form the 'inner sphere' complexes CrF2+(aq), CrCl2+(aq), CrBr2+(aq), and CrSO4+(aq). Results of our measurements lead to ΔHf0 = (−60.0 ± 1.5) kcal mol−1 for Cr3+(aq), ΔHf0 = −136.8 kcal mol−1 for CrF2+(aq), ΔHf0 = −93.7 kcal mol−1 for CrCl2+(aq), ΔHf0 = −80.1 kcal mol−1 for CrBr2+(aq), and ΔHf0 = −269.7 kcal mol−1 for CrSO4+(aq).

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