Logo image
Fluoride solvation-the case of the missing ion
Journal article   Open access   Peer reviewed

Fluoride solvation-the case of the missing ion

G.T. Hefter
Pure and Applied Chemistry, Vol.63(12), pp.1749-1758
1991
pdf
fluoride_solvation.pdfDownloadView
Published (Version of Record) Open Access
url
Link to Published Version *Subscription may be requiredView

Abstract

The thermodynamics of fluoride ion solvation in nonaqueous and mixed aqueous solvents are reviewed. Gibbs energies of transfer , ∆tG⁰ (F -) H20-s , indicate that the solvation of the fluoride ion is dominated by hydrogen bonding. Thus, ∆tG⁰ (F -) H20-s is unfavourable for virtually all solvents, especially dipolar aprotics, and correlates well with solvent acceptor strength. The corresponding enthalpy and entropy data are few and are of low quality but suggest F- solvation is entropy controlled: the only ion known to be so. In mixed aqueous solvents the values of ∆tG⁰ (F -) H20-s generally increase monotonically with declining water content. However, this results from the fortuitous cancellation of dramatic, but largely opposing, variations in ∆tH⁰ and ∆tS⁰. The complex changes in these parameters are related to subtle changes in ion-solvent and solvent-solvent interactions. Finally, a relationship between fluoride and hydroxide solvation is proposed.

Details

Metrics

515 File views/ downloads
107 Record Views
Logo image