Dielectric studies of the switch-over mechanism in the principal relaxation process of alkan-1-ols

Abstract

Dielectric absorption studies have been made on the alkan-1-ols in inert and weakly interacting solvent over a wide range concentration at various temperatures and in the frequency range 10⁶–10⁹ Hz. Some representative alcohols have also been studied in the strongly hydrogen bonding solvents, diethyl ether and di-n-butyl ether. It has been found that not only does the flexible chain of the alkan-1-ol influence the enthalpy of activation on its dilution with a dialkyl ether, but the chain length of the latter also exerts an influence. Altogether the work strongly supports a switch-over type of mechanism as being involved in the principal relaxation process of the alkan-1-ols. The data for the alkan-1-ols in n-heptane and toluene solutions have been employed to test more quantitatively a switch-over theory, and for the shorter-chain alkan-1-ols this has been found to yield reasonable agreement between the measured and estimated principal relaxation time (τ₁) over a wide range of concentration and temperature.