Temperature Dependence of DMR Splittings in Nematic PAA: A Quantitative Interpretation in Terms of Changes in the Molecular Conformation—Comparison with Other Models

Abstract

It is shown that the deuterium magnetic resonance data of Emsley et al. (Mol. Phys. 37, 959(1979) on nematic PAA, can be quantitatively explained in terms of a single order parameter model which permits changes in the most probable conformation. The question of straight line plots of ratios of splittings introduced by Bos and Doane (Phys. Rev. Lett. 40, 1030 (1978)) in the framework of a two order parameter model, is discussed in detail. In the case of PAA, it is shown that the single order parameter model also predicts such plots, and a simple geometrical interpretation of this result is given for this particular case. Comments on other approaches to the same data are also made.