Nuclear quadrupole and magnetic resonance studies of structure and the molecular motion in SYM C6Cl 3F 3

Abstract

35Cl and 19F relaxation time measurements were carried out on sym C 6Cl 3F 3. The analyses of the 19F high-resolution NMR spectra and the 35Cl spin-lattice relaxation time showed that the crystal belongs to a trigonal or a hexagonal crystal system in which the molecules undergo three-fold reorientation about the molecular figure axis with the correlation time τ c/s=3.42·10 −7 exp(18.2 kJ mol −1/ RT). Temperature dependences of the 35Cl NQR frequency and 19F spin-lattice relaxation times are such that only a minor structural change is associated with the phase transition at 296 K.