aInstitute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
bDepartment of Chemistry, National Taiwan University, Taipei, Taiwan
cGraduate Institute of Clinical Dentistry, National Taiwan University, Taipei, Taiwan
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.