An NQR and NMR study of solid trichlorofluoromethane

Abstract

35Cl nuclear quadrupolar resonance linewidth and spin-lattice relaxation time and 19F nuclear magnetic resonance lineshape and spin-lattice relaxation time measurements are reported for polycrystalline trichlorofluoromethane over the temperature range 80 to 160 K. The possibility of lattice vacancies as a mechanism for the 35Cl line broadening and the nuclear relaxation is discussed and rejected. It is concluded that the dominant motional mechanism above 120 K is the reorientation of the molecules around the threefold axis characterized by an activation energy of 27.2 kJ mol −1. A two-exponential analysis of the 19F nonexponential relaxation gives almost the same activation energy. The 19F lineshape shows a structure suggesting that the molecules arrange themselves in a very different way than they do in related CYX 3 compounds.