Conductivity, viscosity and IR spectra of Li, Na and Mg perchlorate solutions in propylene carbonate/water mixed solvents

Abstract

The influence of water addition on the electric conductivity, viscosity and IR spectra of Mg, Li and Na perchlorate solutions in propylene carbonate (PC) was examined. Conductivity and viscosity data pointed out ion–solvent and ion–ion associations that were most pronounced in Mg(ClO₄)₂ solutions. IR investigations were directed towards the spectral region 1000–600 cm^-1. The changes of the ν₄ band of the perchlorate anion at 624 cm^-1 and the changes of solvent bands in the spectral region 980–890 cm^-1 caused by water addition to 1 M solutions indicated the formation of contact ion pairs. The appearance and increase in intensity of the otherwise IR-inactive perchlorate band at 931 cm^-1, upon water addition, was attributed to cation–H₂O–ClO₄^- solvent shared ion pairs.