Optically Polarized 129Xe in NMR Spectroscopy*

Abstract

¹²⁹ Xe has found widespread applications in NMR spectroscopy, but its use is often restricted by its low sensitivity and long relaxation times. Optical pumping of rubidium followed by spin exchange with xenon provides a well understood technique to enhance the ¹²⁹ XePolarization by several orders of magnitude. The exploitation of this highly spin‐polarized xenon as a surface probe in NMR studies of various meterials is discussed. Applications of this technique make use not only of ¹²⁹Xe NMR detection, but also of the‐high spin polarization as a magnetization reservoir for selective cross‐polarization experiments to surface nuclei. A diverse variety of materials has been studied, ranging from mesoscopic structures such as semiconductor nanocrystals and porous silicon to high surface area polymers.