Partial Molar Volumes of 15-Crown-5 Ether in Mixtures of N,N-Dimethylformamide with Water

Magdalena Tyczyńska,Małgorzata Jóźwiak

doi:10.1007/s10953-014-0138-7

Abstract

The density of 15-crown-5 ether (15C5) solutions in the mixtures of N,N-dimethylformamide (DMF) and water (H2O) was measured within the temperature range 293.15–308.15 K using an Anton Paar oscillatory U-tube densimeter. The results were used to calculate the apparent molar volumes (V Φ) of 15C5 in the mixtures of DMF + H2O over the whole concentration range. Using the apparent molar volumes and Redlich and Mayer equation, the standard partial molar volumes of 15-crown-5 were calculated at infinite dilution ( V_{text{m}}^{^circ } ). The limiting apparent molar expansibilities (α) were also calculated. The data are discussed from the point of view of the effect of concentration changes on interactions in solution.

Highlights

Studies of the properties of solutions connected with their density within a wide range of concentration and temperatures are a valuable source of information
In this paper we present the effect of the mixed solvent composition and temperature on the volumetric properties of the system 15-crown-5 ether (15C5) ? DMF ? H2O
Where M is a molar mass of 15C5, qo is the density of DMF ? H2O mixtures, q indicates the density of the 15C5 ? DMF ? H2O system and m is the concentration of 15C5 in moles per kilogram of solvent

Summary

Introduction

Studies of the properties of solutions connected with their density within a wide range of concentration and temperatures are a valuable source of information. The investigation of changes in the interactions among the components of mixed solvent and solute with hydrophobic–hydrophilic properties requires one to choose an organic solvent that does not react with water. This will allow one to observe changes in the interactions among the mixture components and solute, brought about by the process of preferential solvation including the hydrophobic hydration of the solute. Crown ethers constitute a very interesting class of compounds characterized by hydrophilic–hydrophobic properties resulting from their structure They are capable of selective complexation of ions and small organic molecules; for example, they are used to make ion selective electrodes [12]. The data are compared with analogous results previously obtained for the solutions of urea (a hydrophilic compound) in the mixtures of DMF and water [21]

Materials

Measurements

Results and Discussion

Conclusion