PROTON CHEMICAL SHIFT OF WATER IN QUATERNARY AMMONIUM SALT-ELECTROLYTE MIXTURES

Abstract

The proton chemical shifts of water were measured in solutions of mixtures of quaternary ammonium salts (Me4NCl and Me3BeNCl) and metal chlorides (LiCl, KCl, CsCl and MgCl2) as a function of the metal chloride molality. Two additivity rules were examined: (1) eq. (1) which evaluates the contribution of the metal salt by the actual concentration in the mixture solution. where Δν′_??_ means the difference between the chemical shifts of the mixture solution and the reference ammonium salt solution, a1, b1 are the constants, x1 is the mole fraction of the metal chloride and mt is the molality of the salt mixture in solution, and (2) eq. (2) which evaluates the metal salt contribution per mole by the total concentration of the salt mixture. The difference, Δν′_??_, for the mixtures including Me4NCl was explained by rule (2), but not by rule (1). On the other hand, the difference for the mixtures including Me3BeNCl was not accounted for by either rule. We suggest that this divergence may be related to Me3BeN+-Me3BeN+ interaction in the relevant solutions.