Nuclear magnetic resonance from a quasi two dimensional fluid

Abstract

Pulsed Fourier transform nuclear magnetic resonance spectra of a quasi two-dimensional fluid, neopentane adsorbed upon graphite, have been measured. Large upfield chemical shifts arising from the diamagnetic anisotropy of the graphite substrate have been observed for the fluid phase and are consistent with the two-dimensional character of the layer. The shifts allow an estimate of the mean molecule-surface distance to be made. Diffusion constant measurements show an enhanced translational mobility compared with the bulk liquid at the same temperature. Spin-lattice and spin-spin relaxation time measurements cannot be explained by the theory of spin relaxation in bulk liquids but are in qualitative agreement with the behaviour predicted by theories of nuclear spin relaxation in two dimensions.