Dielectric properties of 2-methoxyethanol and 1,2-dimethoxyethane: Comparison with ethylene glycol

Low-frequency dielectric constants epsilon of 2-methoxyethanol (MOE) and 1,2-dimethoxyethane (DME) were measured as a function of temperature (-20 divided by +50 degrees C), and the best fittings are given in an exponential form. Dipole moments mu of the same molecules wore measured at different temperatures (DME at 25 degrees C, MOE at 25, 39. 55 degrees C) in diluted solutions of apolar solvents (CCl4 and C6H6). The values of epsilon and u are compared with those previously published. Also the density rho of DME was measured as a function of temperature (-10 divided by +40 degrees C) and the best fitting is given in a linear form. The correlation factor g, introduced by Kirkwood, is calculated for the two molecules and is compared with that of ethylene glycol (EG) calculated from the available data. The g values are discussed in the light of previous conformational studies, in order to give further insight into the association networks formed by intermolecular H bond. The results support the idea of the existence of three-dimensional branched structures in EG.