Calculation of the structural parameters of 1,2,6-hexanetriol associates

The dispersion of the dielectric permittivity epsilon*(omega) of 1,2,6-hexa netriol over the temperature range 238-423 K were analyzed within the frame work of the DH cluster model. The relaxation frequency omega (p) and the pa rameters of intra-n and intercluster rn correlation were determined. The ca lculated cluster dipole moment <(<mu>)over bar>(c) was found to decrease fr om 656 to 12.64 D with as the temperature increased. The ratio <(<mu>)over bar>(c)/mu (v) (mu (v) is the dipole moment of the molecule in vacuum) for 1,2,6-hexanetriol clusters was found to be higher than the average number o f molecules in chain associates of n-hexanol. The energy barrier height B t hat needs to be overcome during the libration of the 1,2,6-hexanetriol mole cules comprising a cluster was found to he 812 J/mol. The temperature depen dence of the activation energy was described by a fourth-order polynomial, a procedure that made it possible to calculate the relaxation time with an uncertainty below 7%. The values of the activation energy at 413 and 423 K, 37.73 and 34.42 kJ/mol were found to be close to the values of the activat ion enthalpy for the low-frequency dispersion of the permittivity of 1,2- a nd 1,3-propanediols (35 and 32 kJ/mol, respectively). These activation ener gies were attributed to the rearrangement of the network structure: of the diols via the formation and dissociation of intramolecular and intermolecul ar H-bonds.