Nuclear magnetic resonance studies of preferential solvation. Part 7.—Sodium iodide in ethylene glycol–acetonitrile and in propylene glycol–acetonitrile mixtures
Abstract
23 Na n.m.r. chemical shifts and iodide ion CTTS band maxima have been used as probes for ion–ion and ion–solvent interactions for NaI in ethylene glycol (EG)–acetonitrile (AN) and propylene glycol (PG)–acetonitrile mixtures. Since EG–AN mixtures are approximately isodielectric, changes in ion–solvent interactions on transfer from the pure solvents to EG–AN mixtures can be attributed to changes in the short-range, ‘chemical’ interactions. In combination with a stepwise thermodynamic model for solvation in a binary solvent taking into account non-ideal solvent behaviour, quantitative evidence for preferential solvation by the glycol component was obtained.