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

最近开发的多量子（MQ）魔角旋转（MAS）和卫星跃迁（ST） MAS实验允许仅使用传统硬件就可以在固体中获得重要的四极核，如17- 0,23 - na和27-Al的真正高分辨率NMR光谱。这些新技术已经在学术界和工业界广泛应用于研究矿物、玻璃、沸石和其他微孔材料。自1995年以来，我们一直致力于这些方法的开发，我们在这一领域的研究已经获得了广泛的国际认可。之前的两个EPSRC资助项目（GR/M12209和GR/N07622）发表了超过25篇论文，并得到了评审人员的高度评价，但这两个项目现在都已经过期了。本建议的目的是使我们能够进一步发展STMAS方法。这是一项特别令人兴奋的新技术，因为它比旧的MAMAS方法具有更高的灵敏度，而许多有趣和不寻常的自旋相互作用仅在STMAS光谱中得到证实。这项技术在很大程度上仍处于起步阶段，因为它是在2000年GRIN07622拨款授予之后才出现的。特别是，我们计划进一步提高该技术的灵敏度，并将STMAS核磁共振实验发展为(a)记录高分辨率的25-Mg， 47-Ti和95-Mo光谱而不需要同位素富集的方法，以及(b)研究二阶交叉项和三阶四极相互作用对卫星跃迁的影响。我们还致力于进一步开发STMAS的新型SCAM（自补偿角度偏差）变体。

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.