Low-Frequency Dielectric Absorption and Direct-Current Conductivity in Quinol

Abstract

THE large dielectric absorption at low frequencies recently observed¹ in crystalline long-chain alcohols has been shown to be probably due to a hydrogen bonding of the hydroxyl groups to form chains. Hydrogen-bonded hydroxyl groups are also present in the dihydric phenol quinol, according to a structure proposed from X-ray crystallographic data², but in this case the hydrogen bonds form regular hexagons. With such a structure the resultant dipole moment should be zero and the compound should give no dielectric absorption. However, in recent measurements in this laboratory, considerable low-frequency absorption was observed in three samples of quinol crystallized from water, ethanol and methanol respectively. This absorption decreased with time of storage at room temperature, as shown in the graph (p. 1122) of the results for the sample crystallized from water. The curves are similar in shape to those obtained previously for n-hexadecyl alcohol³, in which the dielectric absorption was attributed to the presence of extensive hydrogen-bond chains, and it seems likely that the results for quinol can be similarly explained.