Satellite-Transition MAS: A New Technique for High-Resolution Quadrupolar NMR

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The recently developed multiple-quantum (MQ) magic-angle-spinning (MAS) and satellite-transition (ST) MAS experiments allow truly high-resolution NMR spectra of important quadrupolar nuclei, such as 17-0, 23-Na and 27-Al, to be obtained in solids using only conventional hardware. These new techniques are already being used extensively in both academia and industry to study minerals, glasses, zeolites and other microporous materials. We have been working on the development of these methods since 1995 and our research in this area has achieved wide international recognition. The two previous EPSRC grants that supported this work (GR/M12209 and GR/N07622) yielded over 25 publications and were rated extremely highly by assessors, but both have now expired.The aim of the the present proposal is to allow us to develop the STMAS method further. This is a particularly exciting new technique as it has much higher sensitivity than the older MAMAS method, while a number of interesting and unusual spin interactions are evidenced only in STMAS spectra. The technique is still very much in its infancy, since it appeared only during 2000, after the award of grant GRIN07622. In particular, we plan to improve the sensitivity of the technique still further and to develop the STMAS NMR experiment as a method of (a) recording high-resolution 25-Mg, 47-Ti and 95-Mo spectra without isotopic enrichment, and (b) studying the effects of second-order cross-term and third-order quadrupolar interactions on satellite transitions. We also aim to develop further our new SCAM (self-compensated for angle misset) variant of STMAS.