A study of out-of-plane cation dynamics in a bis-thiourea pyridinium chloride inclusion compound

作者：Pajzderska A^*; Czarnecki P; Embs J P; Gonzalez M A; Juranyi F; Krawczyk J; Peplinska B; Wasicki J

来源：Physical Chemistry Chemical Physics, 2011, 13(19): 8908-8914.

DOI：10.1039/c0cp02716b

The out-of-plane motion of the pyridinium cation in the bis-thiourea pyridinium chloride inclusion compound has been studied in a wide temperature range using (1)H NMR, dielectric spectroscopy and quasielastic neutron scattering. The geometry of this motion is obtained from the Q-dependence of the elastic incoherent structure factor determined from the quasielastic neutron scattering measurements. We find that the pyridinium cation performs out-of-plane reorientations around the axis passing through two opposite atoms of the ring. The correlation times as a function of temperature were measured in the three known crystallographic phases, finding a good agreement between the three techniques employed. The activation energy for this motion changes from 5 +/- 1 kJ mol(-1) in the low-temperature phase to 1.2 +/- 0.2 kJ mol(-1) in the intermediate and high-temperature phases.

• 出版日期2011