Bajnóczi, Eva
- University of Szeged
Abstract
The identity of the predominating tin(II)-hydroxide complex formed in hyper-alkaline aqueous solutions (0.2 <= C-NaOH <= 12 mol dm(-3)) is determined by potentiometric titrations, Raman, Mossbauer and XANES spectroscopy, supplemented by quantum chemical calculations. Thermodynamic studies using a H-2/Pt electrode up to free hydroxide concentrations of 1 mol dm(-3) showed the presence of a single monomeric complex with a tin(II) : hydroxide ratio of 1 : 3. This observation together with Raman and Mossbauer spectroscopic measurements supplemented by quantum mechanical calculations proved that the predominating complex is [Sn(OH)(3)](-), and that the presence of the other possible complex, [SnO(OH)](-), could not be proven with either experiments or simulations. The structure of the trihydroxidostannate(II) complex, [Sn(OH)(3)](-), was determined by EXAFS and was found to be independent of the applied hydroxide and tin(II) concentrations. The mean Sn-O bond distance is short, 2.078 angstrom, and in very good agreement with the only structure reported in the solid state. It is also shown that at pH values above 13 the speciation of the predominant trihydroxidostannate(II) complex is not affected by the presence of high concentrations of chloride ions.
Keywords
Hyper-alkaline aqueous solution; tin(II); speciation; structure
Published in
Dalton Transactions
2014, volume: 43, number: 48, pages: 17971–17979
SLU Authors
Persson, Ingmar
- The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
- The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
UKÄ Subject classification
Inorganic Chemistry
Publication identifier
- DOI: https://doi.org/10.1039/c4dt02706j
Permanent link to this page (URI)
https://res.slu.se/id/publ/63420