PROGRESS IN HIGH RESOLUTION SOLID STATE NMR OF QUADRUPOLAR NUCLEI: APPLICATIONS TO POROUS MATERIALS AND CATALYSTS

摘要

Several new experiments are reviewed that combine multiple quantum magic angle spinning (MQMAS) NMR with cross polarization (CP) or heteronuclear recoupling via REDOR. The advantage of these techniques is that they provide direct inference of the connectivities between spin-1/2 and half-integer quadrupolar nuclei in the isotropic spectra of the latter. Additionally, the MQ-REDOR methods yield the internuclear distances in these systems. We have demonstrated the capabilities of these techniques in the studies of ~1H-~(27)A1 and ~(19)F-~(27)AI spin pairs in aluminophosphate molecular sieves.