The interaction of water with non-electrolytes. The system water–acetonitrile–1,4-dioxane

Abstract

¹ H, ¹³C and ¹⁷O magnetic resonance has been used to investigate the degree of modification of the aqueous structure in water–acetonitrile–1,4-dioxane mixtures of different compositions. Chemical-shift data of the hydrogen and oxygen nuclei of water have enabled the calculation of a parameter (ƒ_M), which may be considered representative of the average situation experienced by one molecule of water in the presence of one molecule of non-electrolyte. Chemical-shift data of the hydrogen and carbon nuclei of acetonitrile and dioxan have been used to determine similar parameters (ƒ^AN_M and ƒ^DO_M) representative of the situation experienced by one molecule of water in the presence of one molecule of acetonitrile or dioxane, respectively. The values of ƒ^AN_M and ƒ^DO_M accord with those of ƒ_M, and indicate that the degree of modification of the aqueous structure is generally independent of the composition of the non-electrolyte.