A XANES and EXAFS Study of Hydration and Ion Pairing in Ambient Aqueous MnBr[subscript 2] Solutions
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 MnBr{sub 2} 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 {yields} 4p transition at 6545.5 eV confirmed the observation of Mn-Br contact ion pairs at high concentrations and the 1s {yields} 3d transition at 6539.5 eV showed that the first shell coordination symmetry remained octahedral even in the presence of Mn-Br ion pairs.
- Authors:
-
- PNNL
- Publication Date:
- Research Org.:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1008624
- Resource Type:
- Journal Article
- Journal Name:
- J. Solution Chem.
- Additional Journal Information:
- Journal Volume: 34; Journal Issue: (9) ; 09, 2005; Journal ID: ISSN 0095-9782
- Country of Publication:
- United States
- Language:
- ENGLISH
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION; ATOMS; BROMINE; COORDINATION NUMBER; FINE STRUCTURE; HYDRATION; ION PAIRS; PROBES; SATURATION; SPECTRA; SYMMETRY; WATER
Citation Formats
Chen, Yongsheng, Fulton, John L, Partenheimer, Walter, and DuPont). A XANES and EXAFS Study of Hydration and Ion Pairing in Ambient Aqueous MnBr[subscript 2] Solutions. United States: N. p., 2008.
Web.
Chen, Yongsheng, Fulton, John L, Partenheimer, Walter, & DuPont). A XANES and EXAFS Study of Hydration and Ion Pairing in Ambient Aqueous MnBr[subscript 2] Solutions. United States.
Chen, Yongsheng, Fulton, John L, Partenheimer, Walter, and DuPont). 2008.
"A XANES and EXAFS Study of Hydration and Ion Pairing in Ambient Aqueous MnBr[subscript 2] Solutions". United States.
@article{osti_1008624,
title = {A XANES and EXAFS Study of Hydration and Ion Pairing in Ambient Aqueous MnBr[subscript 2] Solutions},
author = {Chen, Yongsheng and Fulton, John L and Partenheimer, Walter and DuPont)},
abstractNote = {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 MnBr{sub 2} 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 {yields} 4p transition at 6545.5 eV confirmed the observation of Mn-Br contact ion pairs at high concentrations and the 1s {yields} 3d transition at 6539.5 eV showed that the first shell coordination symmetry remained octahedral even in the presence of Mn-Br ion pairs.},
doi = {},
url = {https://www.osti.gov/biblio/1008624},
journal = {J. Solution Chem.},
issn = {0095-9782},
number = (9) ; 09, 2005,
volume = 34,
place = {United States},
year = {Thu Sep 25 00:00:00 EDT 2008},
month = {Thu Sep 25 00:00:00 EDT 2008}
}