High-field cross polarization NMR from laser-polarized xenon to a polymer surface

We report the use of laser-polarized xenon as the source of magnetization for a high-field cross polarization experiment, obtaining surface-selective magnetization transfer. Contact between laser-polarized xenon and surface spins was achieved in high field by Hartmann-Hahn matching of the energy levels in the rotating frame with direct NMR detection of the polarized species. Proton spins are observed due to their abundance at the surface and the dominant dipolar interactions with adsorbed xenon. The sample, poly(triarylcarbinol) is a microporous, hypercross-linked, rigid-rod polymer. We have demonstrated that under favorable circumstances (high surface area, long relaxation time), laser-polarized, adsorbed xenon can be used to selectively transfer spin order to surface spins. 13 refs., 3 figs.