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The structure of Fe(III) ions in strongly alkaline aqueous solutions from EXAFS and Mossbauer spectroscopy

Sipos, Pal; Zeller, Dalma; Kuzmann, Erno; Vertes, Attila; Homonnay, Zoltan; Walczak, Monika LU and Canton, Sophie LU (2008) In Dalton Transactions p.5603-5611
Abstract
To establish the structure of ferric ions in strongly alkaline (pH > 13) environments, aqueous NaOH solutions supersaturated with respect to Fe(III) and the solid ferric-hydroxo complex salts precipitating from them have been characterized with a variety of experimental techniques. From UV measurements, in solutions of pH > 13, only one kind of Fe(III)-hydroxo complex species was found to be present. The micro crystals obtained from such solutions were proven to be a new, so far unidentified solid phase. Mossbauer spectra of the quick-frozen solution and that of the complex salt indicated a highly symmetrical ferric environment in both systems From the EXAFS and XANES spectra, the environment of the ferric ion in these solutions... (More)
To establish the structure of ferric ions in strongly alkaline (pH > 13) environments, aqueous NaOH solutions supersaturated with respect to Fe(III) and the solid ferric-hydroxo complex salts precipitating from them have been characterized with a variety of experimental techniques. From UV measurements, in solutions of pH > 13, only one kind of Fe(III)-hydroxo complex species was found to be present. The micro crystals obtained from such solutions were proven to be a new, so far unidentified solid phase. Mossbauer spectra of the quick-frozen solution and that of the complex salt indicated a highly symmetrical ferric environment in both systems From the EXAFS and XANES spectra, the environment of the ferric ion in these solutions (both native and quick-frozen) and in the complex salt was found to be different. In the complex salt, the bond lengths are consistent with an octahedral coordination around the ferric centres. In solution, the coordination geometry of Fe(III) is most probably tetrahedral. Our results demonstrate that in strongly alkaline aqueous solutions, ferric ions behave very similarly to other structurally related tervalent ions, like Al(III) or Ga(III). (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Dalton Transactions
issue
41
pages
5603 - 5611
publisher
Royal Society of Chemistry
external identifiers
  • wos:000260023300012
  • scopus:54049145119
ISSN
1477-9234
DOI
10.1039/b806937a
language
English
LU publication?
yes
id
5bf9167c-bf3b-4f0b-9b5c-58c95ccf28eb (old id 1286771)
date added to LUP
2009-01-29 15:46:57
date last changed
2017-08-13 03:42:56
@article{5bf9167c-bf3b-4f0b-9b5c-58c95ccf28eb,
  abstract     = {To establish the structure of ferric ions in strongly alkaline (pH > 13) environments, aqueous NaOH solutions supersaturated with respect to Fe(III) and the solid ferric-hydroxo complex salts precipitating from them have been characterized with a variety of experimental techniques. From UV measurements, in solutions of pH > 13, only one kind of Fe(III)-hydroxo complex species was found to be present. The micro crystals obtained from such solutions were proven to be a new, so far unidentified solid phase. Mossbauer spectra of the quick-frozen solution and that of the complex salt indicated a highly symmetrical ferric environment in both systems From the EXAFS and XANES spectra, the environment of the ferric ion in these solutions (both native and quick-frozen) and in the complex salt was found to be different. In the complex salt, the bond lengths are consistent with an octahedral coordination around the ferric centres. In solution, the coordination geometry of Fe(III) is most probably tetrahedral. Our results demonstrate that in strongly alkaline aqueous solutions, ferric ions behave very similarly to other structurally related tervalent ions, like Al(III) or Ga(III).},
  author       = {Sipos, Pal and Zeller, Dalma and Kuzmann, Erno and Vertes, Attila and Homonnay, Zoltan and Walczak, Monika and Canton, Sophie},
  issn         = {1477-9234},
  language     = {eng},
  number       = {41},
  pages        = {5603--5611},
  publisher    = {Royal Society of Chemistry},
  series       = {Dalton Transactions},
  title        = {The structure of Fe(III) ions in strongly alkaline aqueous solutions from EXAFS and Mossbauer spectroscopy},
  url          = {http://dx.doi.org/10.1039/b806937a},
  year         = {2008},
}