Raman study of cation effect on sulfate vibration modes in solid state and in aqueous solutions
Article first published online: 11 SEP 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Volume 44, Issue 11, pages 1603–1608, November 2013
How to Cite
Ben Mabrouk, K., Kauffmann, T. H., Aroui, H. and Fontana, M. D. (2013), Raman study of cation effect on sulfate vibration modes in solid state and in aqueous solutions. J. Raman Spectrosc., 44: 1603–1608. doi: 10.1002/jrs.4374
- Issue published online: 8 NOV 2013
- Article first published online: 11 SEP 2013
- Manuscript Accepted: 9 AUG 2013
- Manuscript Revised: 8 AUG 2013
- Manuscript Received: 12 JUN 2013
- cation dependence;
- Raman study
Raman spectra of potassium, sodium, and ammonium sulfates (K2SO4, Na2SO4, and (NH4)2SO4) are reported and analyzed. These sulfates have been investigated under two states: solid (anhydrous and hydrated) salts and aqueous solutions. The effects of monovalent ions (K+, Na+, and NH4+) and hydration on the position of Raman lines assigned to internal vibrations of sulfate anion SO42− are discussed. In solid salts, the line position of each Raman peak is shown to decrease with increasing radius of the cation. The main ν1 mode of sulfate molecule is particularly affected. It is emphasized that this sensitivity in solid sulfates vanishes in aqueous solutions. As a consequence, this mode can be probed by Raman spectroscopy as the main signature of SO42− to determine its concentration within a single calibration. Copyright © 2013 John Wiley & Sons, Ltd.