Number of inner-sphere water molecules in Gd3+ and Eu3+ complexes of DTPA-amide and -ester conjugates

1988 ◽  
Vol 8 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Carlos F. G. C. Geraldes ◽  
A. Dean Sherry ◽  
William P. Cacheris ◽  
Kah-Tiong Kuan ◽  
Rodney D. Brown ◽  
...  
Keyword(s):  
Water Molecules ◽  
Inner Sphere

Determination of the number of inner-sphere water molecules in lanthanide(III) polyaminocarboxylate complexes

1992 ◽  
pp. 463 ◽  
Author(s):  
M. Carmen Alpoim ◽  
Ana M. Urbano ◽  
Carlos F. G. C. Geraldes ◽  
Joop A. Peters
Keyword(s):  
Water Molecules ◽  
Inner Sphere

Hyperfine Coupling Constants on Inner-Sphere Water Molecules of a Triazacyclononane-based Mn(II) Complex and Related Systems Relevant as MRI Contrast Agents

2013 ◽  
Vol 52 (19) ◽  
pp. 11173-11184 ◽  
Author(s):  
Véronique Patinec ◽  
Gabriele A. Rolla ◽  
Mauro Botta ◽  
Raphaël Tripier ◽  
David Esteban-Gómez ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Hyperfine Coupling ◽  
Mri Contrast Agents ◽  
Coupling Constants ◽  
Water Molecules ◽  
Hyperfine Coupling Constants ◽  
Mri Contrast ◽  
Inner Sphere

Quantum chemical study of inner-sphere complexes of trivalent lanthanide and actinide ions on the corundum (110) surface

2013 ◽  
Vol 101 (9) ◽  
pp. 561-570
Author(s):  
R. Polly ◽  
B. Schimmelpfennig ◽  
M. Flörsheimer ◽  
Th. Rabung ◽  
T. Kupcik ◽  
...  
Keyword(s):  
Metal Ions ◽  
Density Functional ◽  
Single Point ◽  
Quantum Chemical Study ◽  
Basis Sets ◽  
Water Molecules ◽  
Point Energy ◽  
Inner Sphere ◽  
Sphere Complex ◽  
Inner Sphere Complexes

Summary Sorption plays a major role in the safety assessment of nuclear waste disposal. In the present theoretical study we focused on understanding the interaction of trivalent lanthanides and actinides (La3+, Eu3+ and Cm3+) with the corundum (110) surface. Optimization of the structures were carried out using density functional theory with different basis sets. Additionally, Møller-Plesset perturbation theory of second order was used for single point energy calculations. We studied the structure of different inner-sphere complexes depending on the surface deprotonation and the number of water molecules in the first coordination shell. The most likely structure of the inner-sphere complex (tri- or tetradentate) was predicted. For the calculations we used a cluster model for the surface. By deprotonating the cluster a chemical environment at elevated pH values was mimicked. Our calculations predict the highest stability for a tetradentate inner-sphere surface complexes with five water molecules remaining in the first coordination sphere of the metal ions. The formation of the inner-sphere complexes is favored when a coordination takes place with at most one deprotonated surface aluminol group located beneath the inner-sphere complex. The mutual interaction between sorbing metal ions at the surface is studied as well. The minimal possible distance between two inner-sphere sorbed metal ions at the surface was determined to be 530 pm.

Molecular Dynamics of Cation Hydration in the Presence of Carboxylated Molecules: Implications for Calcification

2011 ◽  
Vol 1301 ◽  
Author(s):  
Laura M. Hamm ◽  
Adam F. Wallace ◽  
Patricia M. Dove
Keyword(s):  
Molecular Dynamics ◽  
Divalent Cations ◽  
Bulk Water ◽  
Ion Pair ◽  
Water Molecules ◽  
Residence Times ◽  
Polymorph Selection ◽  
Inner Sphere ◽  
Cation Hydration ◽  
Kinetics Of

ABSTRACTBiomolecules rich in aspartic acid (Asp) are known to play a role in biomineral morphology and polymorph selection, and have been shown to greatly enhance the growth kinetics of calcite. The mechanism by which these compounds favor calcification may be related to their effects upon cation solvation. Using molecular dynamics, we investigated the influence of small carboxylated molecules on the hydration states and water exchange rates of divalent cations. We show that the carboxylate moieties of Asp promote dehydration of Ca2+ and Sr2+ and that contact ion pair (CIP) formation is not required to disrupt the hydration of these cations. Ca2+- Asp and Sr2+ - Asp CIP formation decreases the total inner sphere coordination from an average of 8.0 and 8.4 in bulk water to 7.5 and 8.0, respectively. Water residence times estimated for Mg2+, Ca2+and Sr2+ follow the expected trend of decreasing residence time with increasing ionic radius. In the presence of Asp, both solvent-separated ion pair (SSIP) and CIP formation decrease the residence times of Ca2+and Sr2+ inner sphere water molecules. Comparable impacts on Mg2+ hydration are not observed. Mg2+ - Asp CIP formation is energetically unfavorable and Asp does not affect Mg2+ inner sphere water residence times.

Hyperfine Coupling Constants on Inner-Sphere Water Molecules of GdIII-Based MRI Contrast Agents

ChemPhysChem ◽  
2012 ◽  
Vol 13 (16) ◽  
pp. 3640-3650 ◽  
Author(s):  
David Esteban-Gómez ◽  
Andrés de Blas ◽  
Teresa Rodríguez-Blas ◽  
Lothar Helm ◽  
Carlos Platas-Iglesias
Keyword(s):  
Contrast Agents ◽  
Hyperfine Coupling ◽  
Mri Contrast Agents ◽  
Coupling Constants ◽  
Water Molecules ◽  
Hyperfine Coupling Constants ◽  
Mri Contrast ◽  
Inner Sphere
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