Journal of Solution Chemistry

, Volume 34, Issue 9, pp 993–1007

A XANES and EXAFS Study of Hydration and Ion Pairing in Ambient Aqueous MnBr2 Solutions

  • Yongsheng Chen
  • John L. Fulton
  • Walter Partenheimer
Article

DOI: 10.1007/s10953-005-6986-4

Cite this article as:
Chen, Y., Fulton, J.L. & Partenheimer, W. J Solution Chem (2005) 34: 993. doi:10.1007/s10953-005-6986-4

Abstract

Extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectroscopies were used to probe the first-shell coordination structure of Mn(II) in aqueous MnBr2 solutions at ambient conditions from very dilute to the near saturation limit. The Mn K-edge EXAFS spectra for 0.05 and 0.2 m solutions showed that there was no Br(−I) in the first shell, and that the Mn(II) was fully hydrated with six water molecules in an octahedral arrangement. In contrast, for 6 m solution, the coordination number of water was reduced to about 5, and an average of about one bromine atom was present in the first shell as a contact ion pair. The 1s → 4p transition at 6545.5 eV confirmed the observation of Mn–Br contact ion pairs at high concentrations and the 1s → 3d transition at 6539.5 eV showed that the first shell coordination symmetry remained octahedral even in the presence of Mn–Br ion pairs.

Keywords

XANES EXAFS manganese bromide aqueous solution hydration structure 

Copyright information

© Springer Science + Business Media, Inc. 2005

Authors and Affiliations

  • Yongsheng Chen
    • 1
  • John L. Fulton
    • 1
  • Walter Partenheimer
    • 2
  1. 1.Fundamental Science DivisionPacific Northwest National LaboratoryRichland
  2. 2.Central Research and DevelopmentE. I. DuPont de Nemours & Co., Inc.Wilmington