Open AccessThe pH dependence of Am(III) complexation with acetate: an EXAFS study
Author(s) -
Fröhlich Daniel R.,
SkerencakFrech Andrej,
Bauer Nicole,
Rossberg André,
Panak Petra J.
Publication year - 2015
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577514022498
Subject(s) - extended x ray absorption fine structure , chemistry , coordination number , denticity , genetic algorithm , absorption spectroscopy , absorption (acoustics) , analytical chemistry (journal) , crystallography , materials science , crystal structure , organic chemistry , physics , ion , quantum mechanics , evolutionary biology , composite material , biology
The complexation of acetate with Am(III) is studied as a function of the pH (1–6) by extended X‐ray absorption fine‐structure (EXAFS) spectroscopy. The molecular structure of the Am(III)–acetate complexes (coordination numbers, oxygen and carbon distances) is determined from the raw k 3 ‐weighted Am L III ‐edge EXAFS spectra. The results show a continuous shift of Am(III) speciation with increasing pH value towards the complexed species. Furthermore, it is verified that acetate coordinates in a bidentate coordination mode to Am(III) (Am—C distance: 2.82 ± 0.03 Å). The EXAFS data are analyzed by iterative transformation factor analysis to further verify the chemical speciation, which is calculated on the basis of thermodynamic constants, and the used structural model. The experimental results are in very good agreement with the thermodynamic modelling.