Comparison of the Macroscopic Molecular Properties in Understanding the Structural Aspects of Mixed Aquo–Organic Binary Mixtures

Abstract

Understanding the structural aspects of aquo + organic mixtures and finding out a suitable physico-chemical parameter as a structural probe is of great importance from a theoretical and experimental point of view.

Attempts have been made to derive useful relations regarding the structure of aquo + organic mixtures [ethylene glycol + water, glycerol + water, dioxane + water, acetone + water and acetonitrile + water mixtures] of widely divergent characteristics based on different macroscopic molecular properties: (i) excess thermodynamic properties of mixing, (ii) excess dielectric constants, (iii) excess polarizability volumes, (iii) correlation factor ‘g’, (v) ultrasonic sound absorption, (vi) basicity or other suitable expressions. The properties give valuable details regarding the structure of aquo + organic mixtures.

Macroscopic molecular properties provide a summary of all interaction energies over a long time, but finer structural details may be available from microscopic properties (using relaxation techniques etc.).

A comparison of the macroscopic and microscopic methods for the determination of structural aspects of solvent systems is presented.