Structural and kinetic studies on uranyl(V) carbonate complex using C-13 NMR spectroscopy
2005 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 13, 4472-4474 p.Article in journal (Refereed) Published
We have measured C-13 NMR spectra of uranyl(V) carbonate complex in D2O solution containing 1.003 M Na-2 (CO3)-C-13 at various temperatures. Two singlet signals corresponding to free and coordinated CO32- were observed at 169.13 and 106.70 ppm, respectively. From the peak area ratio, the structure of the uranyl(V) carbonate complex was determined as [(UO2)-O-V(CO3)(3)](5-). Furthermore, kinetic analyses of the exchange reaction of free and coordinated CO32- in [(UO2)-O-V(CO3)(3)](5-) were carried out using 13C NMR line-broadening. As a result, the first-order rate constant at 298 K and the activation parameters for CO32- exchange reaction in [(UO2)-O-V(CO3)(3)](5-) were evaluated as 1.13 x 10(3) s(-1) and Delta H-not equal = 62.0 +/- 0.7 KJ(.)mol(-1), Delta S-not equal = 22 +/- 3 J(.)mol(-1.)K(-1), respectively. We suggest that the exchange follows a dissociative mechanism as in the corresponding [(UO2)-O-VI(CO3)(3)](4-) complex.
Place, publisher, year, edition, pages
2005. Vol. 44, no 13, 4472-4474 p.
NUCLEAR MAGNETIC-RESONANCE, LIGAND-EXCHANGE REACTIONS, AQUEOUS-SOLUTION, WATER EXCHANGE, URANIUM(V), REDUCTION, C-13, ACETYLACETONATE, SPECTROSCOPY, MECHANISMS
IdentifiersURN: urn:nbn:se:kth:diva-37852DOI: 10.1021/ic050308xISI: 000229982700011ScopusID: 2-s2.0-22544467767OAI: oai:DiVA.org:kth-37852DiVA: diva2:435401
QC 201108182011-08-182011-08-182011-08-18Bibliographically approved