0000000000541923
AUTHOR
Simone Bénazeth
Recent Achievement and Perspectives in Synchrotron Radiation X-Ray Absorption Spectroscopy
During the last 20 years, x-ray absorption spectroscopy (XAS) has found extensive application in the materials science [1, 2, 3]. solution chemistry [4], biology [5]. therapeutic chemistry [6] and geochemistry. However. it is relatively recently XAS methods have been utilized for measurements on archaeological materials [7,8].
Temperature and pH Dependence of Gd-DOTA and Gd-DTPA Complexes Dissociation Studied by EXAFS
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…