Nuclear Magnetic Resonance Study of Solid Perfluorocyclohexane

A nuclear magnetic resonance second-moment study of perfluorocyclohexane over the temperature range +25° to —130°C gave evidence for a rotational transition at about —95°C. This transition was indicated by a sharp decrease in the second moment from a value of 9.6 to 0.5 G2. Theoretical second moments agreed favorably with the experimental rigid-lattice value, if the chair form of the molecule was assumed. In addition, spin—lattice relaxation times were measured as a function of temperature. Again rotational motion in the solid was indicated by a sharp minimum in the T1 vs T curve at about —93°C.