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

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.