✍ Scribed by Ē. Kupče; P.A. Keifer; M. Delepierre
No coin nor oath required. For personal study only.
The effect of magic angle spinning (MAS) of liquids upon the performance of various isotropic mixing sequences is investigated. Although the mathematical formalism for isotropic mixing under MAS conditions is similar for both liquids and solids, the mechanism through which the coherence transfer is disturbed is different. In liquids, the use of sample spinning in the presence of both RF and magnetic-field inhomogeneities introduces a modulation of the effective field, which compromises the performance of the conventional mixing sequences. This effect is further amplified by supercycles, which normally improve the performance of the mixing and decoupling experiments. It is demonstrated that adiabatic mixing sequences are less susceptible to such modulations and perform considerably better in TOCSY MAS experiments. The best performance of TOCSY MAS is observed under the rotational resonance condition when the sample appears static in the nutation reference frame.
📜 SIMILAR VOLUMES
Adiabatic spin inversion has been used in the liquid state very efficiently for decoupling purposes. Here we show that it can also be adapted for spin mixing experiments, such as the TOCSY and clean TOCSY experiment, and is superior to previously employed mixing sequences. The main advantage of adia