@article {488, title = {Solid-state Al-27 NMR studies of aluminophosphate molecular sieves}, journal = {Solid State Nuclear Magnetic Resonance}, volume = {1}, year = {1992}, note = {Solid State Nucl MagV26hsTimes Cited:12Cited References Count:33}, month = {Nov}, pages = {217-225}, abstract = {Solid-state Al-27 NMR spectra of several aluminophosphate molecular sieves have been recorded with conventional magic-angle spinning (MAS), double-rotation (DOR) and quadrupole nutation with fast MAS. Enhanced resolution was obtained in the quadrupole nutation experiment at certain radiofrequency pulse strengths. This extra resolution can be comparable to that attainable using DOR, and does not introduce spinning sidebands.}, keywords = {double-rotation}, isbn = {0926-2040}, url = {://WOS:000208537300007}, author = {Rocha, J. and Klinowski, J. and Barrie, P. J. and Jelinek, R. and Pines, A.} } @article {508, title = {Study of the Aluminophosphates Alpo4-21 and Alpo4-25 by Al-27 Double-Rotation Nmr}, journal = {Journal of the American Chemical Society}, volume = {113}, year = {1991}, note = {J Am Chem SocFn005Times Cited:53Cited References Count:16}, month = {May 22}, pages = {4097-4101}, abstract = {

Aluminum-27 double-rotation NMR in a magnetic field of 11.7 T distinguishes the extremely distorted five-coordinated aluminum sites in the molecular sieve precursor ALPO4(-21). Upon calcination, ALPO4(-21) transforms to ALPO4(-25), which has two tetrahedral aluminum sites with similar isotropic chemical shifts that cannot be resolved in an 11.7 T field. The two tetrahedral environments, however, have a different quadrupole coupling constants and are distinguished by double rotation at 4.2 T field. The quadrupole coupling constants obtained for these sites indicates that the tetrahedral aluminum environments are less distorted in the hydrated material.

}, keywords = {nuclei}, isbn = {0002-7863}, doi = {Doi 10.1021/Ja00011a007}, url = {://WOS:A1991FN00500007}, author = {Jelinek, R. and Chmelka, B. F. and Wu, Y. and Grandinetti, P. J. and Pines, A. and Barrie, P. J. and Klinowski, J.} }