NMR Studies of Ion Solvation in Water

One of the most important applications of NMR spectroscopy is the determination of the solvation number of ions in aqueous solutions. This can be accomplished in some cases using NMR or using NMR in isotopically enriched 

When the rate of solvent exchange around the ion is fast, only one line is seen in the NMR spectrum. In this case, the H nucleus in the solvent may experience all possible environments in the solution within the time corresponding to the 

Cations Cation Chemical Shift / ppm Solvation Number 

The trends for the alkali metals and alkaline earth metals are separated by 0.033 ppm. As argued by Davies et al. [13], this difference gives the effect of the extra Cl ion which is in the alkaline earth metal solution (MCI2). By shifting the dependence for the alkaline earth metal chloride solutions down by two times 0.033 ppm, and that for the alkali metal chlorides down by 0.033 pm, one trend is 

Electrolyte Chemical ShifC 8 / ppm kg mol Electrolyte Chemical ShifC 8 / ppm kg mol  

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