Quadrupolar nuclei half-integer

The MQMAS experiment is technically straightforward and has truly revolutionized solid-state NMR of half-integer quadrupolar nuclei (see Sects. 5.3, 5.4, 6, and 7). 

The CP can also be used for polarization transfer to MQ coherences of half-integer quadrupolar nuclei [222, 223, 228-231]. This type of transfer is mainly used in the context of MQMAS [228,229,231], although the spin-locking of MQ coherences is also featured in experiments involving homonuclear dipolar recoupling experiments [232]. 

Vega, A.J. (1992) MAS NMR spin locking of half-integer quadrupolar nuclei./. Magn. Reson., 96, 50-68. 

Samoson, A. and Lippmaa, E. (1983) Excitation phenomena and line intensities in high-resolution NMR powder spectra of half-integer quadrupolar nuclei. Phys. Rev. E, 28, 6567-6570. 

Gan, Z. (2000) Isotropic NMR spectra of half-integer quadrupolar nuclei using satellite transitions and magjc-angle spinning. /. Am. Chem. Soc., 122, 3242-3243. 

A. P. M. Kentgens, A practical guide to solid-state NMR of half-integer quadrupolar nuclei with some applications to disordered systems. Geoderma, 1997, 80,271-306. 

J. Trebosc, J.-P. Amoureux and Z. Gan, Comparison of high-resolution solid-state NMR MQMAS and STMAS methods for half-integer quadrupolar nuclei. Solid State Nucl. Magn. Reson., 2007, 31,1-9. 

F. H. Larsen, H. J. Jakobsen, P. D. ElUs and N. C. Nielsen, Sensitivity-enhanced quad-rupolar-echo NMR of half-integer quadrupolar nuclei. Magnitudes and relative orientation of chemical shielding and quadrupolar coupling tensors. /. Phys. Chem. A, 1997, 101,8597-8606. 

R. Siegel, T. T. Nakashima and R. E. Wasylishen, Signal enhancement of NMR spectra of half-integer quadrupolar nuclei in solids using hyperbolic secant pulses. Chem. Phys. Lett, 2004, 388,441 5. 

R. W. Schurko, 1. Hung and C. M. Widdifield, Signal enhancement in NMR spectra of half-integer quadrupolar nuclei via DFS-QCPMG and RAPT-QCPMG pulse sequences. Chem. Phys. Lett., 2003, 379,1-10. 

Central transitions, half-integer quadrupolar nuclei NM R spectra, 1, 457, 1, 464 Ceramics... 

CS tensors for complex spectra, 1, 463 dicyclopentadienylberyllium compounds, 2, 74 tj4-diene and rf-allyl pseudo-rotations, 1, 416 half-integer quadrupolar nuclei, central transition, 1, 457 half-integer spin quadrupolar nuclei central transition,... 

Contents 1. Introduction 104 2. Theory 106 2.1. Specifically for spin-1 nuclei 112 2.2. Two-axis jump processes 114 2.3. 2-by-2-site jump 114 2.4. 2-by-3-site jump 115 3. Numerical Simulations 117 3.1. Spin-1 nuclei 118 3.2. Half-integer quadrupolar nuclei 118 4. Results and Discussion 119 4.1. Spin-1 nuclei 119 4.2. Dynamic effects in 14N MAS spectra by SQ or DQ coherences 123 4.3. Multi-axis jump processes 124 4.4. Half-integer quadrupolar nuclei 129 5. Conclusions 134 Acknowledgements 135 References 135... 

Analysis of molecular motion in solids using NMR spectroscopy has been a developing field during the past decades. In this context, 2H NMR is the most used approach but recently a number of other quadrupolar nuclei have been studied. This includes spin-1 as well as half-integer quadrupolar nuclei such as 7Li and 23Na. 

Most NMR-groups exploring effects of molecular motion tend to develop their own software to simulate these effects. Recently the simulation program EXPRESS developed by Void and Hoatson69 was presented. By this program, effects of dynamics can be simulated (see Table 1 in Ref. 69 for details) but so far effects of finite rf-pulses and the motional effects on satellite transitions in half-integer quadrupolar nuclei are not included. 

Taking an experimental point of view variable temperature experiments used for dynamics studies are easiest to perform under static conditions as rotation of the sample cause frictional heating and at very high or very low temperatures it may be difficult to construct MAS probe that would allow sufficiently fast spinning when studying half-integer quadrupolar nuclei. This makes the... 

Cross-Polarization of Half-Integer Quadrupolar Nuclei. 176... 

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