Spectral editing based on selective excitation and Lee-Goldburg cross-polarization under magic angle spinning

Abstract

We show that a Gaussian-shaped pulse can be used to excite selected 1H signals in hydroxyapatite, monetite and H–Y zeolite loaded with trimethylphosphine oxide (TMPO). This selective excitation method can be incorporated into Lee-Goldburg (LG) cross-polarization to obtain useful spectral editing opportunity. This new strategy has been applied to identify the Brønsted and the Lewis acid sites in H–Y zeolite using TMPO as the probe molecule.