Nuclear relaxation and molecular motions in liquid trifluoroacetonitrile

Abstract

1 9F and 14N nuclear magnetic spin-lattice relaxation rates in liquid CF3CN have been measured at 14.1 kG. From 14N relaxation rates, the correlation times of the tumbling motion were directly determined. By separating 19F relaxation rates into terms contributed from the dipolar and the spin-rotational interactions, the correlation times of the spinning motion were also obtained. Spin-rotational relaxation rates were used to estimate the angular momentum correlation times. Gordon’s J diffusion model was found to be appropriate to describe the molecular reorientations of this molecule. Some 13C spin-lattice relaxation rates have also been measured and used to estimate the magnitude of 13C spin-rotational constants and chemical shielding anisotropies.