Multiple-quantum magic-angle spinning spectroscopy

Goldbourt, A. and Madhu, P.K. (2005) Multiple-quantum magic-angle spinning high-resolution NMR spectroscopy of half-integer spin quadrupolar nuclei. Annu. Rep. NMR Spectrosc., 54, 81-153. 

Progress in Multiple-Quantum Magic-Angle Spinning NMR Spectroscopy... 

Abstract Recent advances in nuclear magnetic resonance spectroscopy of quadrupolar (/> 1/2) nuclei with half-integer spins in solids have been reviewed. The advent of multiple-quantum (MQ) magic-angle spinning (MAS) spectroscopy gave new momentum to the study of quadrupolar nuclei in materials of academic and industrial interest such as min-... 

Progress in Multiple-Quantum Magic-Angle Spinning NMR Spectroscopy J. Rocha C. M. Morais C. Fernandez. 141... 

While the main recent advance in NMR has been the development of multidimensional spectroscopy, novel catalytic applications include in situ studies and two-dimensional (2D) solid-state techniques such as correlation spectroscopy, spin diffusion, and quadrupole nutation. Completely new techniques have appeared, such as multiple-quantum spin counting, and old ones have developed in quite unexpected directions. For example, cross-polarization, a 20-year-old experiment, has recently been applied to quadmpolar nuclei to yield important new information on heterogeneous catalysts. Magic-angle spinning (MAS) of quadru-polar nuclei has been extended to methods in which the sample is spun about two different angles either simultaneously or sequentially (DOR and DAS). These experiments have been made possible by the significant advances in NMR instrumentation in the last decade. 

We present a solid-state nuclear magnetic resonance (NMR) experiment that allows the observation of a high-resolution two-dimensional heteronuclear correlation (2D HETCOR) spectrum between aluminum and phosphorous in aluminophosphate molecular sieve VPI-5. The experiment uses multiple quantum magic angle spinning (MQMAS) spectroscopy to remove the second order quadrupolar broadening in Al nuclei. The magnetization is then transferred to spin-1/2 nuclei of P via cross polarization (CP) to produce for the first time isotropic resolution in both dimensions. 

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