Ry. Dong et X. Shen, ROTATIONAL DIFFUSION OF ASYMMETRIC MOLECULES IN LIQUID-CRYSTALS - A GLOBAL ANALYSIS OF DEUTERON RELAXATION DATA, The Journal of chemical physics, 105(5), 1996, pp. 2106-2111
A new global analysis of the relaxation data in the nematic and smecti
c A phases of 4-n-pentyloxybenzylidene-4'-heptylaniline [Phys. Rev. E
49, 538 (1994)] supports a model which includes director fluctuations
and rotational diffusion of an asymmetric rigid rotor in a biaxial pot
ential of mean torque. The molecular biaxiality of the molecule is fou
nd, based on the relaxation data, to give a small positive biaxial ord
er parameter S-yy-S-xx. In addition, the activation energy for the tum
bling motion of the molecule is found to be larger than that for the s
pinning motion. The usefulness of globally analyzing the deuteron rela
xation data at different temperatures and frequencies is demonstrated.
(C) 1996 American Institute of Physics.