Apparent molar volumes and apparent molar adiabatic compressibilities of some symmetricai tetraalkylammonium bromides in 1,2-dimethoxyethane

Abstract

Apparent molar volumes (<i>ф</i>_v) and apparent molar adiabatic compressibilities (<i>ф</i>_K) of four symmetrical tetraalkylammonium bromides have been determined in 1,2-dimethoxyethane from precise density and sound velocity measurements. Limiting apparent molar volumes and adiabatic compressibilities of the salts obtained from the concentration dependence of <i>ф_v </i> and <i>ф</i>_K data are separated into ionic contributions. The data have been quantitatively interpreted in terms of solute-solvent and solute-solute interactions. Strong electrostriction occurs around bromide ions whereas the larger tetraalkylammonium ions which are scarcely solvated in 1,2-dimethoxyethane, cause a greater degree of disorder in the solvent structure.