Structure of Concentrated Aqueous Solutions of Alkaline Earth Metal Chlorides and Bromides
(2026) In Journal of Solution Chemistry- Abstract
The magnesium, calcium, strontium and barium ions bind six, eight, eight and nine water molecules in the first hydration shell, and ca. 12, 16, 16 and 18 water molecules in the second one, in dilute aqueous solution, respectively. With increasing concentration of alkaline earth metal halides, water molecules in the second hydration shell are exchanged for hydrated chloride and bromide ions forming solvent shared ion–pairs. At high concentrations the coordination number of the calcium and strontium ions decreases to seven in aqueous solution, while the magnesium and barium ions maintain their octahedral and nine–coordinate configuration, respectively. In the case of highly concentrated calcium chloride solutions a di– or polymeric... (More)
The magnesium, calcium, strontium and barium ions bind six, eight, eight and nine water molecules in the first hydration shell, and ca. 12, 16, 16 and 18 water molecules in the second one, in dilute aqueous solution, respectively. With increasing concentration of alkaline earth metal halides, water molecules in the second hydration shell are exchanged for hydrated chloride and bromide ions forming solvent shared ion–pairs. At high concentrations the coordination number of the calcium and strontium ions decreases to seven in aqueous solution, while the magnesium and barium ions maintain their octahedral and nine–coordinate configuration, respectively. In the case of highly concentrated calcium chloride solutions a di– or polymeric complex with a double aqua bridge is formed. The inner–coordination shell of water molecules remains in solid magnesium halide hydrates precipitated from aqueous solution. Dimeric and polymeric aqua complexes of hydrated calcium, strontium and barium halides form in the solid state. However, except for highly concentrated calcium chloride solutions, such complexes have not been detected in aqueous solution.
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- author
- Bajnóczi, Éva G. ; Persson, Ingmar and Sigfridsson Clauss, Kajsa LU
- organization
- publishing date
- 2026
- type
- Contribution to journal
- publication status
- epub
- subject
- keywords
- Alkaline earth metal ions, EXAFS, Hydration, Large angle X-ray scattering, Outer sphere halide complexes, Structure in solution
- in
- Journal of Solution Chemistry
- publisher
- Springer
- external identifiers
-
- scopus:105026412493
- ISSN
- 0095-9782
- DOI
- 10.1007/s10953-025-01559-9
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © The Author(s) 2026.
- id
- 2785c2bc-7e7c-4906-9c04-b0e9987b6618
- date added to LUP
- 2026-03-23 11:20:02
- date last changed
- 2026-03-23 11:20:21
@article{2785c2bc-7e7c-4906-9c04-b0e9987b6618,
abstract = {{<p>The magnesium, calcium, strontium and barium ions bind six, eight, eight and nine water molecules in the first hydration shell, and ca. 12, 16, 16 and 18 water molecules in the second one, in dilute aqueous solution, respectively. With increasing concentration of alkaline earth metal halides, water molecules in the second hydration shell are exchanged for hydrated chloride and bromide ions forming solvent shared ion–pairs. At high concentrations the coordination number of the calcium and strontium ions decreases to seven in aqueous solution, while the magnesium and barium ions maintain their octahedral and nine–coordinate configuration, respectively. In the case of highly concentrated calcium chloride solutions a di– or polymeric complex with a double aqua bridge is formed. The inner–coordination shell of water molecules remains in solid magnesium halide hydrates precipitated from aqueous solution. Dimeric and polymeric aqua complexes of hydrated calcium, strontium and barium halides form in the solid state. However, except for highly concentrated calcium chloride solutions, such complexes have not been detected in aqueous solution.</p>}},
author = {{Bajnóczi, Éva G. and Persson, Ingmar and Sigfridsson Clauss, Kajsa}},
issn = {{0095-9782}},
keywords = {{Alkaline earth metal ions; EXAFS; Hydration; Large angle X-ray scattering; Outer sphere halide complexes; Structure in solution}},
language = {{eng}},
publisher = {{Springer}},
series = {{Journal of Solution Chemistry}},
title = {{Structure of Concentrated Aqueous Solutions of Alkaline Earth Metal Chlorides and Bromides}},
url = {{http://dx.doi.org/10.1007/s10953-025-01559-9}},
doi = {{10.1007/s10953-025-01559-9}},
year = {{2026}},
}