Relationship between the structure and thermal properties of 4-n-alkyl-4′-cyanobiphenyls

The relationship between the molecular structure and thermal properties in the homologous series nCB with n = 5-10 is investigated by the Monte Carlo and atom-atomic potential methods by dividing the thermodynamic properties of liquid crystal systems into inter- and intramolecular increments. An explicit even-odd correlation between the intermolecular term of the inner configuration energy U-inter, hear capacity C-V(inter), and the anisotropy of the geometrical form (sigma(parallel to)/sigma(perpendicular to)) of nCB molecules is established It is shown that internal degrees of freedom are responsible to a certain extent for the even-odd effect of some physicochemical properties of nCB. The major contribution to the heat capacity C-v is made by the vibrational motion.