19F spin-rotation tensors in CCl3F and ClO3F and their application to liquid-phase rotational diffusion

Abstract

Shielding anisotropies of 19F nuclei in CCl3F and ClO3F of Δσ=117 and 590 ppm, respectively, were found by analysis of the rigid-lattice NMR line shapes of these molecules enclathrated in D2O hydrates. Spin-rotation interaction tensor components were obtained from the shielding constants and used to derive angular momentum correlation times for these molecules in the liquid from the spin-rotation contribution to the 19F relaxation rates. For CCl3F and ClO3F the available data agree almost quantitatively with the predictions of McClung’s J diffusion model for the relation between angular momentum and orientational correlation times of symmetric top molecules.