Rotational motion in plastic quinuclidine : Results from quasielastic neutron scattering

Abstract

Results of incoherent quasielastic neutron scattering experiments on quinuclidine, C7Hl3N, in its plastic phase (room temperature) are presented. The observed quasielastic spectra are compared to several models for the rotational motion of the molecules. It is found that the data support a picture, where the molecules perform 90°-reorientations about crystallographic C4-axes with a residence time of (24.8 ± 2.5).10-12 s, and 120°-reorientations about the molecular C3-axis with a residence time of (9.6 ± 2.0). 10-12 s