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RESEARCH PRODUCT
Temperature and pH Dependence of Gd-DOTA and Gd-DTPA Complexes Dissociation Studied by EXAFS
J. PuransJ. PuransCh. SouleauA. GaudemerM. C. ChalbotK. NguyenL. NicolasSimone BénazethSimone Bénazethsubject
chemistry.chemical_compoundAqueous solutionchemistryExtended X-ray absorption fine structureScatteringMedium rangeAnalytical chemistryPh dependenceGeneral Physics and AstronomyDOTADissociation (chemistry)X-ray absorption fine structuredescription
The Gd L3-edge of Gd(DTPA) 2- and Gd(DOTA) - complexes, in crystalline state and aqueous solutions presenting various pH (0.15-8) at different temperatures (25-90 °C), are investigated by XAFS experiments. For the Gd(DTPA) 2- . complexes we observe a strong pH (0.15-1.5) dependence of XAFS signals. On the other hand, the XAFS signals of Gd(DOTA) - complexes exhibit a light pH (1-1.5) dependence and for pH<1 we observe a ligand decomposition. Conceming both complexes, we note just a light temperature dependence. To obtain information about the short and medium range order (up to 5 A), multiple scattering calculation is performed. For the first coordination shell, we apply multi-shell fitting and RDF reconstruction. The comparative XAFS and XRD results are discussed, and some discrepancies with previous RMN experiments are underlined.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1997-04-01 | Le Journal de Physique IV |