Combined Computational and Experimental Study of Uranyl(VI) Complexation by Aromatic Acids

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Jonas Wiebke - , University of Cologne (Author)
  • Anna Weigand - , University of Cologne (Author)
  • Daniel Weissmann - , University of Cologne (Author)
  • Maja Glorius - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Henry Moll - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Gert Bernhard - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Michael Dolg - , University of Cologne (Author)

Abstract

The bis(salicylhydroxamato) and bis(benzohydroxamato) complexes of UO22+ in aqueous solution have been investigated in a combined experimental and computational effort using extended X-ray absorption fine structure and UV-vis spectroscopy and density functional theory (DFT) techniques, respectively. The experimentally unknown bis(benzoate) complex of UO22+ was investigated computationally for comparison. Experimental data indicate 5-fold UO22+ coordination with mean equatorial U-O distances of 2.42 and 2.40 angstrom for the salicyl- and benzohydroxamate systems, respectively. DFT calculations on microsolvated model systems [UO2L2OH2] indicate UO22+ eta(2)-chelation via the hydroxamate oxygen atoms in excellent agreement with experimental data; calculated complex stabilities support that UO22+ prefers hydroxamate over carboxylate coordination. The 414 nm absorption band of UO22+ in aqueous solution is blue-shifted to 390 and 386 nm upon complexation by salicyl- and benzohydroxamate, respectively. Calculated time-dependent DFT excitation energies of [UO2L2OH2], however, occasionally fail to reproduce accurately experimental UV-vis spectra, which are dominated by UO22+

Details

Original languageEnglish
Pages (from-to)6428-6435
Number of pages8
JournalInorganic chemistry
Volume49
Issue number14
Publication statusPublished - 19 Jul 2010
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 77955432923
ORCID /0000-0003-0087-5723/work/142250070

Keywords

Keywords

  • WATER EXCHANGE-REACTION, AQUEOUS-SOLUTION, BASIS-SETS, ELECTRONIC-STRUCTURE, MOLECULAR-STRUCTURE, SOLVENT-EXTRACTION, CHARGE-TRANSFER, URANIUM(VI)